A chemical compound is a molecular substance consisting of multiple atoms which are bonded together by a chemical reaction. This type can be used for compounds made of the same element (e.g. allotropes) or multiple different elements. Compounds are different from chemical mixtures because mixtures can be mixed and separated physically, without a reaction.
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Coluracetam (BCI-540) is a nootropic drug of the racetam family. Coluracetam (formerly known as MKC-231) was initially developed and tested by the Mitsubishi Tanabe Pharma Corporation for Alzheimer's disease. After the drug failed to reach endpoints in its clinical trials it was in-licensed by BrainCells Inc for investigations into major depression disorder (MDD), after being awarded a "Qualifying Therapeutic Discovery Program Grant" by the state of California. Findings from its Phase 2a clinical trials have suggested that it would be an ideal medication for co-morbid MDD with generalized anxiety disorder (GAD). BrainCells Inc is currently out-licensing the drug for this purpose. It may also have potential use in prevention and treatment of ischemic retinopathy and retinal and optic nerve injury.
Coluracetam enhances high-affinity choline uptake (HACU) which is the rate-limiting step of acetylcholine (ACh) synthesis, and is the only known choline uptake enhancer to currently exist. Studies have shown Coluracetam to improve learning impairment on a single oral dose given to rats which have been exposed to cholinergic neurotoxins. Subsequent studies have shown that it may induce
Diisopropyl tartrate (DIPT) is a diester of tartaric acid. It has a two chiral carbon atoms giving rise to three stereoisomeric variants. It is commonly used in asymmetric synthesis as a catalyst and as chiral building block for pharmaceuticals and agrochemicals. Its main application is in Sharpless epoxidation, where it serves as a chiral ligand to titanium after reaction with titanium isopropoxide.
Pulegone is a naturally occurring organic compound obtained from the essential oils of a variety of plants such as Nepeta cataria (catnip), Mentha piperita, and pennyroyal. It is classified as a monoterpene.
Pulegone is a clear colorless oily liquid and has a pleasant odor similar to pennyroyal, peppermint and camphor. It is used in flavoring agents, in perfumery, and in aromatherapy.
It was reported that the chemical is toxic to rats if a large quantity is consumed. Asekun et al. found that the chemical content of Mentha longifolia L was decreased by the treatments at high temperatures, suggesting that the herb should be oven dried or thoroughly cooked before consumption.
Thymidine monophosphate, also known as 5'-thymidylate, thymidylate, or TMP, is a nucleotide that is used as a monomer in DNA. It is an ester of phosphoric acid with the nucleoside thymidine. TMP consists of a phosphate group, the pentose sugar deoxyribose, and the nucleobase thymine. Unlike the other deoxyribonucleotides, thymidine monophosphate does not contain the "deoxy" prefix in its name. As a substituent, it takes the form of the prefix thymidylyl-.
Chlorodifluoromethane or difluoromonochloromethane is a hydrochlorofluorocarbon (HCFC). This colorless gas is better known as HCFC-22, or R-22. It is commonly used as a propellant and refrigerant. These applications are being phased out in developed countries due to the compound's ozone depletion potential (ODP) and high global warming potential (GWP), although global use of R-22 continues to increase because of high demand in developing countries. R-22 is a versatile intermediate in industrial organofluorine chemistry, e.g. as a precursor to tetrafluoroethylene.
Worldwide production of R-22 in 2008 was about 800 Gg per year, up from about 450 Gg per year in 1998, with most production in developing countries. R-22 use is increasing in developing countries, largely for air conditioning applications. Air conditioning sales are growing 20% annually in India and China.
R-22 is prepared from chloroform:
An important application of R-22 is as a precursor to tetrafluoroethylene. This conversion involves pyrolysis to give difluorocarbene, which dimerizes:
The compound also yields difluorocarbene upon treatment with strong base and is used in the laboratory as a source of this reactive
Benzamide is an off-white solid with the chemical formula of C6H5CONH2. It is a derivative of benzoic acid. It is slightly soluble in water, and soluble in many organic solvents.
A number of substituted benzamides exist, including:
MCPA or 2-methyl-4-chlorophenoxyacetic acid is a powerful, selective, widely used phenoxy herbicide. The pure compound is a brown-colored powder.
In 1936 investigations began at ICIs Jealott's Hill research centre into the effects of synthetic hormones on plant growth looking specifically for a way to kill weeds without harming crops such as corn.
Synthesis of MCPA was first reported by Synerholme and Zimmerman in 1945 and by Templeman and Foster in 1946. Templeman and Foster were searching for compounds with similar or greater selective activity than 1-naphthaleneacetic acid in inhibiting the growth of weeds while not adversely affecting the growth of cereal grains. They synthesized MCPA from the corresponding phenol by exposing it to chloroacetic acid and dilute base in a straightforward substitution reaction:
MCPA is used as an herbicide, generally as its salt or esterified forms. Used thus, it controls broadleaf weeds, including thistle and dock, in cereal crops and pasture. It is selective for plants with broad leaves, and this includes most deciduous trees. Clovers are tolerant at moderate application levels. It is currently classified as a restricted use pesticide in the
Glufosinate or its ammonium salt DL-phosphinothricin is an active ingredient in several nonselective systemic herbicides such as Basta, Rely, Finale, Ignite, Challenge, and Liberty. It interferes with the biosynthetic pathway of the amino acid glutamine and with ammonia detoxification.
Some plants have been genetically modified for resistance to glufosinate. The gene which gives resistance to glufosinate is a bar or pat gene which was first isolated from two species of Streptomyces bacteria. There are glufosinate-resistant transgenic varieties of several crops, including cotton, canola, corn, soybean, sugarbeet, and rice. Of these, only canola, cotton and maize are currently on the market. This includes Bayer's LibertyLink genes, used in over 100 hybrids.
Glufosinate was included in a biocide ban proposed by the Swedish Chemicals Agency and approved by the European Parliament on January 13, 2009.
In response to Monsanto's hugely successful Roundup Ready crops, Bayer Crop Science released its own herbicide tolerant crops. The range of crops tolerant to the herbicide glufosinate include cotton, soybean, canola and corn. These crops are also known as Liberty Link crops.
Cnicin is a sesquiterpene lactone, esterified with a substituted acrylic acid, and belonging to the germacranolide class of natural products. It is mainly found in Cnicus (Cnicus benedictus L. (Asteraceae)), and is present in spotted knapweed plants, where highest and lowest concentrations are found in the leaves (0.86-3.86% cnicin) and stems respectively. Cnicin is used as a bitter tonic and the bitterness value is approximately 1,500.
Coumarin ( /ˈkuːmərɪn/; 2H-chromen-2-one) is a fragrant organic chemical compound in the benzopyrone chemical class, which is a colorless crystalline substance in its standard state. It is found naturally in many plants, notably in high concentration in the tonka bean (Dipteryx odorata), vanilla grass (Anthoxanthum odoratum), sweet woodruff (Galium odoratum), mullein (Verbascum spp.), sweet grass (Hierochloe odorata), cassia cinnamon (Cinnamomum aromaticum), melilot (Melilotus ssp.), Deers Tongue (Panicum clandestinum) and sweet clover (Fabaceae spp.). The name comes from a French word, coumarou, for the tonka bean. It has a sweet odor, readily recognised as the scent of new-mown hay, and has been used in perfumes since 1882. Sweet woodruff, sweet grass and sweet clover in particular are named for their sweet smell, which in turn is due to their high content of this substance. When it occurs in high concentrations in forage plants, coumarin is a somewhat bitter-tasting appetite suppressant, and is presumed to be produced by plants as a defense chemical in order to discourage predation.
Coumarin has been used as an aroma enhancer in pipe tobaccos and certain alcoholic drinks,
Allyl bromide (1-bromoprop-2-ene) is an organic halide. Its refractive index is 1.4697 (20 °C, 589 nm). Allyl bromide is an alkylating agent used in synthesis of polymers, pharmaceuticals, allyls and other organic compounds. Physically, allyl bromide is a clear liquid with an intense, acrid, and persistent smell. In addition, allylzinc bromide may be produced by treating this compound with elemental zinc. Unlike most organometallic reagents, which are pyrophoric in air and destroyed by water, allylzinc bromide is stable in aqueous solvents and can attack aldehydes in a Barbier-type reaction, leading to carbon-carbon bond formation.
Calcium pyrophosphate (Ca2O7P2) is a chemical compound that can be formed by the reaction of pyrophosphoric acid and a calcium base or by strongly heating calcium phosphate or calcium ammonium phosphate.
It is commonly used as a mild abrasive agent in toothpastes.
Deposition of CPPD in articular joints causes an arthritis condition called pseudogout.
Calendic acid (sometimes α-calendic acid) is an unsaturated fatty acid, named for the pot marigold (genus Calendula), from which it is obtained. It is chemically similar to the conjugated linoleic acids; laboratory work suggests it may have similar health benefits.
Calendic acid is an omega-6 fatty acid. though not usually listed with this group. Calendic acid is synthesised in Calendula officinalis from linoleate by an unusual Δ12-oleate desaturase (a FAD 2 variant) that converts the cis-double bond in position 9 to a trans,trans-conjugated double bond system. An all-trans beta isomer has been described.
Calendula flowers have been used for many centuries. Ointments or extracts are applied medicinally for reducing inflammation, wound healing, and as an antiseptic. The US National Institute of Health's MedlinePlus states that there is 'B' grade evidence ('good scientific evidence') for the efficacy of topical use of Calendula in protecting the skin of patients undergoing radiation treatments. It assigns a 'C' grade (Unclear scientific evidence) for uses in ear infection, skin inflammation and wound and burn healing.
Calendic acid is the fatty acid responsible for the reduction in
Morpholine is an organic chemical compound having the chemical formula O(CH2CH2)2NH. This heterocycle, pictured at right, features both amine and ether functional groups. Because of the amine, morpholine is a base; its conjugate acid is called morpholinium. For example, neutralizing morpholine with hydrochloric acid makes the salt morpholinium chloride.
Morpholine may be produced by the dehydration of diethanolamine with sulfuric acid:
Morpholine is a common additive, in parts per million concentrations, for pH adjustment in both fossil fuel and nuclear power plant steam systems. Morpholine is used because its volatility is about the same as water, so once it is added to the water, its concentration becomes distributed rather evenly in both the water and steam phases. Its pH adjusting qualities then become distributed throughout the steam plant to provide corrosion protection. Morpholine is often used in conjunction with low concentrations of hydrazine or ammonia to provide a comprehensive all-volatile treatment chemistry for corrosion protection for the steam systems of such plants. Morpholine decomposes reasonably slowly in the absence of oxygen at the high temperatures and
Sodium percarbonate is a chemical, an adduct of sodium carbonate and hydrogen peroxide (a perhydrate), with formula 2Na2CO3 · 3H2O2. It is a colorless, crystalline, hygroscopic and water-soluble solid. It is used in some eco-friendly cleaning products and as a laboratory source of anhydrous hydrogen peroxide.
This product contains the carbonate anion, and should not be confused with sodium peroxocarbonate Na2CO4 or peroxodicarbonate Na2C2O6, which contain different anions.
At room temperature, solid sodium percarbonate has the orthorhombic crystal structure, with the Cmca crystallographic space group. The structure changes to Pbca as the crystals are cooled below about −30 °C.
Sodium percarbonate is produced industrially by reaction of sodium carbonate and hydrogen peroxide, followed by crystallization. Also, dry sodium carbonate may be treated directly with concentrated hydrogen peroxide solution. World production capacity of this compound was estimated at several hundred thousand tonnes for 2004. It can be obtained in the laboratory by treating the two substances in aqueous solution with proper control of the pH or concentrations.
As an oxidizing agent, sodium percarbonate is an
Neurine is an alkaloid found in egg yolk, brain, bile and in cadavers. It is formed during putrefaction of biological tissues by the dehydration of choline. It is a poisonous, syrupy liquid with a fishy odor.
Neurine is a quaternary ammonium salt with three methyl groups and one vinyl group attached to the nitrogen atom. Synthetically, neurine can be prepared by the reaction of acetylene with trimethylamine. Neurine is unstable and decomposes readily to form trimethylamine.
Sotolon (also known as sotolone) is a lactone and an extremely powerful aroma compound, with the typical smell of fenugreek or curry at high concentrations and maple syrup, caramel, or burnt sugar at lower concentrations. Sotolon is the major aroma and flavor component of fenugreek seed and lovage, and is one of several aromatic and flavor components of artificial maple syrup. It is also present in molasses, aged rum, aged sake and white wine, flor sherry, roast tobacco, and dried fruiting bodies of the mushroom Lactarius helvus. Sotolon can pass through the body relatively unchanged, and consumption of foods high in sotolon, such as fenugreek, can impart a maple syrup aroma to one's sweat and urine. In some individuals with the genetic disorder maple syrup urine disease, it is spontaneously produced in their bodies and excreted it in their urine, leading to the disease's characteristic smell.
This molecule is thought to be responsible for the mysterious maple syrup smell that has occasionally wafted over Manhattan since 2005.
Vin jaune is marked by the formation of sotolon from α-ketobutyric acid.
Ascorbyl palmitate is an ester formed from ascorbic acid and palmitic acid creating a fat-soluble form of vitamin C. In addition to its use as a source of vitamin C, it is also used as an antioxidant food additive (E number E304). It is approved for use as a food additive in the EU, USA and Australia and New Zealand.
Ascorbyl palmitate taken orally is, in all probability, far less effective than the claims made by advertisers and marketers. This is due to the fact that ascorbyl palmitate is known to be broken down (through the digestive process) into ascorbic acid and palmitic acid (a saturated fatty acid) before being absorbed into the bloodstream. Ascorbyl palmitate is also marketed as "vitamin C ester".
Cholesterol, from the Greek chole- (bile) and stereos (solid) followed by the chemical suffix -ol for an alcohol, is an organic chemical substance classified as a waxy steroid of fat. It is an essential structural component of mammalian cell membranes and is required to establish proper membrane permeability and fluidity.
In addition to its importance within cells, cholesterol also serves as a precursor for the biosynthesis of steroid hormones, bile acids, and vitamin D. Cholesterol is the principal sterol synthesized by animals; in vertebrates it is formed predominantly in the liver. Small quantities are synthesized in other cellular organisms (eukaryotes) such as plants and fungi. It is almost completely absent among prokaryotes (i.e., bacteria).
Although cholesterol is important and necessary for human health, high levels of cholesterol in the blood have been linked to damage to arteries and cardiovascular disease.
François Poulletier de la Salle first identified cholesterol in solid form in gallstones, in 1769. However, it was only in 1815 that chemist Eugène Chevreul named the compound "cholesterine".
Since cholesterol is essential for all animal life, each cell synthesizes it
Aconitic acid is an organic acid. The two isomers are cis-aconitic acid and trans-aconitic acid. The conjugate base of cis-aconitic acid, cis-aconitate is an intermediate in the isomerization of citrate to isocitrate in the citric acid cycle. It is acted upon by the enzyme aconitase.
Aconitic acid can be synthesized by dehydration of citric acid using sulfuric acid:
It was first prepared by thermal dehydration.
Aniracetam (Draganon, Sarpul, Ampamet, Memodrin, Referan) is an ampakine and nootropic of the racetam chemical class purported to be considerably more potent than piracetam. It is lipid-soluble and has possible cognition-enhancing effects. It has been tested in animals extensively, Alzheimer's patients, and temporarily-impaired healthy subjects. It has shown potential as an anxiolytic in three clinical animal models. It is sold in Europe as a prescription drug, but can be purchased in most countries without a prescription.
After a confirmed test of the anxiolytic efficacy in a mouse model, haloperidol, mecamylamine, and ketanserin were applied to determine the pathways aniracetam depends on to exert its anti-anxiety effects. Haloperidol completely reversed the anxiolytic effects, and mecamylamine and ketanserin nearly completely reversed the effects. This shows that aniracetam's anxiolytic mechanism is facilitated by D2/D3, nACh, and 5-HT2A receptors.
Aniracetam has also been shown to selectively modulate the AMPA receptor and was used as the parent compound to derive a class of drugs known as the ampakines that are being investigated as nootropics and neuroprotective drugs for the
Piceid is a stilbenoid glucoside and is a major resveratrol derivative in grape juices. It can be found in the bark of Picea sitchensis. It can also be isolated from Polygonum cuspidatum, the Japanese knotweed (syn. Fallopia japonica).
Trans-piceid is the glucoside formed with trans-resveratrol, while cis-piceid is formed with cis-resveratrol.
Trans-resveratrol-3-O-glucuronide is a metabolite of trans-resveratrol-3-O-glucoside.
Resveratrol glucoside from transgenic alfalfa has been used for the prevention of aberrant crypt foci in mice.
Resveratrol can be produced from piceid fermented by Aspergillus oryzae.
Syringaldehyde is an organic compound that occurs in trace amounts widely in nature. Some species of insects use syringaldehyde in their chemical communication systems. Scolytus multistriatus uses it as a signal to find a host tree during oviposition.
Because it contains many functional groups, it can be classified in many ways - aromatic, aldehyde, phenol. It is a colorless solid (impure samples appear yellowish) that is soluble in alcohol and polar organic solvents. Its refractive index is 1.53.
Syringaldehyde can be found naturally in the wood of spruce and maple trees.
This compound may be prepared by the Duff reaction:
Oxalosuccinic acid is a substrate of the citric acid cycle. It is acted upon by isocitrate dehydrogenase. Salts and esters of oxalosuccinic acid are known as oxalosuccinates.
Oxalosuccinic acid/Oxalosuccinate is an unstable 6-Carbon intermediate in the TriCarboxylic Acid Cycle. It's an alpha-keto compound, formed during the oxidative decarboxylation of isocitrate to Alpha-Ketoglutarate, which is catalyzed by the enzyme Isocitrate Dehydrogenase. Oxalosuccinate never leaves the active site of the enzyme, however it's unstable and immediately undergoes decarboxylation to produce the 5-carbon compound, Alpha-Ketoglutarate.
Fluorescein is a synthetic organic compound available as a dark orange/red powder soluble in water and alcohol. It is widely used as a fluorescent tracer for many applications.
Fluorescein is a fluorophore commonly used in microscopy, in a type of dye laser as the gain medium, in forensics and serology to detect latent blood stains, and in dye tracing. Fluorescein has an absorption maximum at 494 nm and emission maximum of 521 nm (in water). The major derivatives are fluorescein isothiocyanate (FITC) and, in oligonucleotide synthesis, 6-FAM phosphoramidite.
Fluorescein also has an isosbestic point (equal absorption for all pH values) at 460 nm. Fluorescein is also known as a color additive (D&C Yellow no. 7). The disodium salt form of fluorescein is known as uranine or D&C Yellow no. 8.
The color of its aqueous solution varies from green to orange as a function of the way it is observed: by reflection or by transmission, as it can be noticed in bubble levels in which fluorescein is added as a colorant to the alcohol filling the tube to increase the visibility of the air bubble and the precision of the instrument. More concentrated solutions of fluorescein can even appear red.
Reverse triiodothyronine (3,3',5'-Triiodothyronine, reverse T3, or rT3) is a molecule that is an isomer of triiodothyronine (T3). It is derived from thyroxine.
rT3 increases in conditions such as sick euthyroid syndrome. rT3 is an inactive form of thyroid hormone. It increases in euthyroid syndrome because its clearance decreases while its production stays the same. The decreased clearance is possibly from lower 5'-deiodinase activity in the peripheral tissue or decreased liver uptake of rT3.
In chemistry, the organic compound triphenylene is a flat polycyclic aromatic hydrocarbon (PAH) consisting of four fused benzene rings. Triphenylene can be isolated from coal tar, but it is also made synthetically using benzyne chemistry, as it is a trimer of benzyne. One molecule of triphenylene has delocalized 18-π-electron systems based on a planar structure. It has the molecular formula C18H12.
Triphenylene is a fully benzenoid PAH, meaning its structure is composed only of full benzene rings interconnected by carbon-carbon single bonds. The three benzene rings can be drawn as the three outer rings, with the central ring formed by one face of each and the three carbon-carbon single bonds.
Being a fully bezenoid PAH means that triphenylene is much more resonance stable than its isomers chrysene, benz[a]anthracene, benzo[c]phenanthrene, and tetracene. This makes it much more difficult to hydrogenate to the saturated hydrocarbon.
In light of these characteristics, triphenylene may have uses in optics and electronics. Triphenylene is a disc-shaped molecule with a planar structure and three-fold rotation axes. Consisting of colorless needle-like crystals, it emits bluish purple
Tryptamine is a monoamine alkaloid found in plants, fungi, and animals. It contains an indole ring structure, and is structurally similar to the amino acid tryptophan, from which it derives its name. Tryptamine is found in trace amounts in the brains of mammals and is believed to play a role as a neuromodulator or neurotransmitter.
The tryptamine chemical structure is the backbone for a group of compounds termed collectively tryptamines. This group includes many biologically active compounds, including neurotransmitters and psychedelic drugs.
The concentration of tryptamine in rat brains is about 3.5 pmol/g.
Many plants contain small amounts of tryptamine, for example, as a possible intermediate in one biosynthetic pathway to the plant hormone indole-3-acetic acid. Higher concentrations can be found in many Acacia species.
Tryptamine acts as a serotonin releasing agent and a serotonergic activity enhancer. It is metabolised by MAO-A and MAO-B.
Well-known tryptamines include serotonin, an important neurotransmitter, and melatonin, a hormone involved in regulating the sleep-wake cycle. Tryptamine alkaloids found in fungi, plants and animals are sometimes used by humans for their
Hydrogen sulfide (British English: hydrogen sulphide) is the chemical compound with the formula H2S. It is a colorless, very poisonous, flammable gas with the characteristic foul odor of rotten eggs. It often results from the bacterial breakdown of organic matter in the absence of oxygen, such as in swamps and sewers; this process is commonly known as anaerobic digestion. It also occurs in volcanic gases, natural gas, and some well waters. The human body produces small amounts of H2S and uses it as a signaling molecule.
Hydrogen sulfide is slightly heavier than air; a mixture of H2S and air is explosive. Hydrogen sulfide and oxygen burn with a blue flame to form sulfur dioxide (SO2) and water. In general, hydrogen sulfide acts as a reducing agent.
At high temperature or in the presence of catalysts, sulfur dioxide can be made to react with hydrogen sulfide to form elemental sulfur and water. This is exploited in the Claus process, the main way to convert hydrogen sulfide into elemental sulfur.
Hydrogen sulfide is slightly soluble in water and acts as a weak acid, giving the hydrosulfide ion HS (pKa = 6.9 in 0.01-0.1 mol/litre solutions at 18 °C). A solution of hydrogen sulfide in
Cytidine triphosphate is a pyrimidine nucleoside triphosphate.
CTP is a substrate in the synthesis of RNA.
CTP is a high-energy molecule equal to ATP, but its role in the organism is more specific than that of ATP. CTP is used as the source of energy, and as a coenzyme in metabolic reactions like the synthesis of glycerophospholipids and glycosylation of proteins.
CTP also acts as an inhibitor of the enzyme Aspartate carbamoyltransferase, which is used in pyrimidine biosynthesis.
Sodium salicylate is a sodium salt of salicylic acid. It can be prepared from sodium phenolate and carbon dioxide under higher temperature and pressure. Historically, it has been synthesized from methyl salicylate (found in wintergreen plants or the bark of sweet birch tree) by reacting it with an excess of sodium hydroxide and heating it under reflux.
Sodium salicylate is of the salicylate family and this compound is known to trigger Reye's Syndrome in children and adults, usually following a viral infection such as influenza or chicken pox. Products containing such salicylates should not be given to children under the age of 19.
It is used in medicine as an analgesic and antipyretic. Sodium salicylate also acts as non-steroidal anti-inflammatory drug (NSAID), and induces apoptosis in cancer cells and also necrosis. It is also a potential replacement for aspirin for people sensitive to it. It may also be used as a phosphor for the detection of vacuum ulraviolet radiation and electrons.
L-Kynurenine is a metabolite of the amino acid L-tryptophan used in the production of niacin. It has been associated with tics.
The primary product of the liver enzyme tryptophan dioxygenase is kynurenine. Cancers upregulate tryptophan dioxygenase because kynurenine increases tumor growth..
Kynureninase catabolizes the conversion of kynurenine into anthranilic acid while kynurenine-oxoglutarate transaminase catabolizes its conversion into kynurenic acid. Kynurenine 3-hydroxylase converts kynurenine to 3-hydroxykynurenine.
Xantphos is an organophosphorus compound derived from the heterocycle xanthene. It is used as a bidentate ligand and is noteworthy for having a particularly wide bite angle. Such ligands are useful in the hydroformylation of alkenes. Illustrative of its wide bite angle, it forms both cis and trans adducts of platinum(II) chloride. A related bidentate ligand with a greater bite angle is spanphos.
The ligand is prepared by double directed lithiation of 9,9-dimethylxanthene with sec-butyllithium followed by treatment with chlorodiphenylphosphine.
Pyridine is a basic heterocyclic organic compound with the chemical formula C5H5N. It is structurally related to benzene, with one C-H group replaced by a nitrogen atom. The pyridine ring occurs in many important compounds, including azines and the vitamins niacin and pyridoxal.
Pyridine was discovered in 1849 by the Scottish chemist Thomas Anderson as one of the constituents of bone oil. Two years later, Anderson isolated pure pyridine through fractional distillation of the oil. It is a colorless, highly flammable, weakly alkaline, water-soluble liquid with a distinctive, unpleasant fish-like odor.
Pyridine is used as a precursor to agrochemicals and pharmaceuticals and is also an important solvent and reagent. Pyridine is added to ethanol to make it unsuitable for drinking (see Denatured alcohol). It is used in the in vitro synthesis of DNA, in the synthesis of sulfapyridine (a drug against bacterial and viral infections), antihistaminic drugs tripelennamine and mepyramine, as well as water repellents, bactericides and herbicides. Some chemical compounds, although not synthesized from pyridine, contain its ring structure. They include B vitamins niacin and pyridoxal, an
Serotonin ( /ˌsɛrəˈtoʊnɨn/) or 5-hydroxytryptamine (5-HT) is a monoamine neurotransmitter. Biochemically derived from tryptophan, serotonin is primarily found in the gastrointestinal (GI) tract, platelets, and in the central nervous system (CNS) of animals including humans. It is popularly thought to be a contributor to feelings of well-being and happiness.
Approximately 90% of the human body's total serotonin is located in the enterochromaffin cells in the alimentary canal (gut) , where it is used to regulate intestinal movements. The remainder is synthesized in serotonergic neurons of the CNS, where it has various functions. These include the regulation of mood, appetite, and sleep. Serotonin also has some cognitive functions, including memory and learning. Modulation of serotonin at synapses is thought to be a major action of several classes of pharmacological antidepressants.
Serotonin secreted from the enterochromaffin cells eventually finds its way out of tissues into the blood. There, it is actively taken up by blood platelets, which store it. When the platelets bind to a clot, they disgorge serotonin, where it serves as a vasoconstrictor and helps to regulate hemostasis and
5-Bromouracil (or 5-bromo-2,4(1H,3H)-pyrimidinedione or 5-BrU or 5-BU) is a brominated derivative of uracil that acts as an antimetabolite or base analog, substituting for thymine in DNA, and can induce DNA mutation in the same way as 2-aminopurine. It is used mainly as an experimental mutagen, but its deoxyriboside derivative (5-bromo-2-deoxy-uridine) is used to treat neoplasms.
5-BrU exists in three tautomeric forms that have different base pairing properties. The keto form (shown in the infobox) is complementary to adenine, so it can be incorporated into DNA by aligning opposite adenine residues during DNA replication (see below left). Alternatively, the enol (below right) and ion forms are complementary to guanine. This means that 5-BrU can be present in DNA either opposite adenine or guanine.
The three forms frequently interchange so base-pairing properties can become altered at any time. The result of this is that during a subsequent round of replication a different base is aligned opposite the 5-BrU residue. Further rounds of replication 'fix' the change by incorporating a normal nitrogen base into the complementary strand.
Thus 5-BrU induces a point mutation via base
Dichlorodifluoromethane (R-12), is a colorless gas, and usually sold under the brand name Freon-12, is a chlorofluorocarbon halomethane (CFC), used as a refrigerant and aerosol spray propellant. Complying with the Montreal Protocol, its manufacture was banned in the United States along with many other countries in 1994 due to concerns about damage to the ozone layer. It is soluble in many organic solvents.
It can be prepared by reacting carbon tetrachloride with hydrogen fluoride in the presence of a catalytic amount of antimony pentachloride:
CCl4 + 2HF → CCl2F2 + 2HCl
This reaction can also produce trichlorofluoromethane (CCl3F), chlorotrifluoromethane (CClF3) and tetrafluoromethane (CF4).
The use of chlorofluorocarbons as an aerosol in medicine, for example: USP-approved salbutamol, has been phased out by the U.S. Food and Drug Administration. The use of a different propellant known as hydrofluoroalkane, or HFA, which does not harm the environment has been chosen as the replacement.
R-12 was used in most refrigeration and vehicle air conditioning applications prior to 1994 before being replaced by R-134a, which has a lower ozone depletion potential. 1992-1994 was the time period
Hexyl cinnamaldehyde (hexyl cinnamal) is a common additive in perfume and cosmetic industry as aroma substance. It is found naturally in the essential oil of chamomile.
It is a pale yellow to yellow clear liquid to solid, which is nearly insoluble in water but soluble in oils.
Hexyl cinnamaldehyde is a class B allergen according to DIMDI classification. It is also an irritant in concentrations higher than recommended.
Itaconic acid, or methylenesuccinic acid, is an organic compound. Itaconic acid is a white crystalline powder. Itaconic acid is a naturally occurring compound, non-toxic, and readily biodegradable. The name itaconic was devised as an anagram of aconitic.
Historically, itaconic acid was obtained by the distillation of citric acid. Since the 1960s, it is produced industrially by fermentation of carbohydrates such as glucose using Aspergillus terreus. As such, it is a fully sustainable industrial building block. It is primarily used as a co-monomer in the production of styrene-butadiene-acrylonitrile and acrylate latexes with applications in the paper and architectural coating industry.
Since Cargill, the last of the U.S. companies to manufacture itaconic acid, exited the business, itaconic acid has mainly been procured by importing the product directly from China where it is still made by several different companies.
Denatonium, usually available as denatonium benzoate (under trade names such as BITTER+PLUS, Bitrex or Aversion) and as denatonium saccharide, is the most bitter chemical compound known, with bitterness thresholds of 0.05 ppm for the benzoate and 0.01 ppm for the saccharide. It was discovered in 1958 during research on local anesthetics by MacFarlan Smith of Edinburgh, Scotland, and registered under the trademark Bitrex. Dilutions of as little as 10 ppm are unbearably bitter to most humans. Denatonium salts are usually colorless and odorless solids but are often traded as solutions. They are used as aversive agents to prevent accidental ingestion. Denatonium is used in denatured alcohol, antifreeze, nail biting preventions, respirator mask fit-testing, animal repellents, liquid soaps, and shampoos. It is not known to pose any long-term health risks.
Denatonium is a quaternary ammonium cation. It is a compound of a salt with an inert anion like benzoate or saccharide. The structure of denatonium is related to the local anesthetic lidocaine, differing only by the addition of a benzyl group to the amino nitrogen.
The bitterness of the compound guides most applications of denatonium.
Homocapsaicin is a capsaicinoid and analog and congener of capsaicin in chili peppers (Capsicum). Like capsaicin it is an irritant. Homocapsaicin accounts for about 1% of the total capsaicinoids mixture and has about half the pungency of capsaicin. Pure homocapsaicin is a lipophilic colorless odorless crystalline to waxy compound. On the Scoville scale it has 8 600 000 SHU (Scoville heat units).
Inositol trisphosphate or inositol 1,4,5-trisphosphate (also commonly known as triphosphoinositol; abbreviated InsP3 or IP3), together with diacylglycerol (DAG), is a secondary messenger molecule used in signal transduction and lipid signaling in biological cells. While DAG stays inside the membrane, IP3 is soluble and diffuses through the cell. It is made by hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2), a phospholipid that is located in the plasma membrane, by phospholipase C (PLC).
IP3 is a polyatomic ion with a molecular mass of 420.10 g/mol. Its empirical formula is C6H15O15P3. It is composed of an inositol ring with three phosphate groups bound at the 1, 4, and 5 carbon positions, and three hydroxyl groups bound at positions 2, 3, and 6.
Phosphate groups can exist in three different forms depending on a solution’s pH. Phosphorus atoms can bind three oxygen atoms with single bonds and a fourth oxygen atom using a double/dative bond. The pH of the solution, and thus the form of the phosphate group determines its ability to bind to other molecules. The binding of phosphate groups to the inositol ring is accomplished by phosphor-ester binding (see phosphoric acids
Tropane is a nitrogenous bicyclic organic compound. It is mainly known for a group of alkaloids derived from it (called tropane alkaloids), which include, among others, atropine and cocaine. Tropane alkaloids occur in plants of the families Erythroxylaceae (including coca) and Solanaceae (including mandrake, henbane, deadly nightshade, datura, potato, tomato).
The nitrogen bridge is between C-1 and C-5; there are two asymmetric carbons, but tropane is optically inactive due to symmetry.
8-Azabicyclo[3.2.1]octane (tropane without the N-methyl group) is known as nortropane or nor-tropane.
D-Psicose (D-allulose, D-ribo-2-hexulose, C6H12O6) is an ultralow-energy monosaccharide sugar. It is a C-3 epimer of D-fructose, and is present in small quantities in agricultural products and commercially prepared carbohydrate complexes. It is known as a "rare sugar" because it is rarely found in nature, and even when found, only in small amounts. D-Psicose yields only 0.3% the metabolic energy of the equivalent amount of sucrose. Its name derives from the antibiotic psicofuranine, from which it can be isolated. Research is being conducted into how it can be used in diets to aid in combating hyperglycemia, hyperlipidemia, and obesity.
1,1'-Bis(diphenylphosphino)ferrocene, commonly abbreviated dppf, is an organophosphorous compound commonly used as a ligand in homogeneous catalysis. It contains a ferrocene moiety in its backbone, and is related to other bridged diphosphines 1,2-bis(diphenylphosphino)ethane (dppe).
This compound is commercially available. It may be prepared by treating dilithioferrocene with chlorodiphenylphosphine:
The dilithiation of ferrocene is easily achieved with n-butyllithium in the presence of TMEDA. Many related ligands can be made in this way. The Fe center is typically not involved in the behavior of the ligand.
Dppf readily forms metal complexes. The palladium derivative, (dppf)PdCl2, which is popular for palladium-catalyzed coupling reactions, is prepared by treating dppf with the acetonitrile or benzonitrile adducts of palladium dichloride:
Acridine, C13H9N, is an organic compound and a nitrogen heterocycle. Acridine is also used to describe compounds containing the C13N tricycle.
Acridine is structurally related to anthracene with one of the central CH groups is replaced by nitrogen. Acridine, a colorless solid, was first isolated from coal tar. It is a raw material used for the production of dyes and some valuable drugs. Many acridines, such as proflavine, also have antiseptic properties. Acridine and related derivatives bind to DNA and RNA due to their abilities to intercalate. Acridine orange (3,6-dimethylaminoacridine) is a nucleic acid-selective metachromatic stain useful for cell cycle determination. Acridarsine is formally derived from acridine by replacing the nitrogen atom with one of arsenic, and acridophosphine by replacing it with one of phosphorus.
Acridine was first isolated in 1871 by Carl Gräbe and Heinrich Caro.
Acridine occurs naturally in coal tar. It is separated from coal tar by extracting with dilute sulfuric acid; addition of potassium dichromate to this solution precipitates acridine bichromate. The bichromate is decomposed using ammonia.
Many synthetic processes are known for the production
Dichloromethane (DCM)—or methylene chloride—is an organic compound with the formula CH2Cl2. This colorless, volatile liquid with a moderately sweet aroma is widely used as a solvent. Although it is not miscible with water, it is miscible with many organic solvents.
DCM was first prepared in 1840 by the French chemist Henri Victor Regnault (1810–1878), who isolated it from a mixture of chloromethane and chlorine that had been exposed to sunlight.
DCM is produced by treating either methyl chloride or methane with chlorine gas at 400–500 °C. At these temperatures, both methane and methyl chloride undergo a series of reactions producing progressively more chlorinated products.
The output of these processes is a mixture of methyl chloride, dichloromethane, chloroform, and carbon tetrachloride. These compounds are separated by distillation.
DCM's volatility and ability to dissolve a wide range of organic compounds makes it a useful solvent for many chemical processes. Concerns about its health effects have led to a search for alternatives in many of these applications.
It is widely used as a paint stripper and a degreaser. In the food industry, it has been used to decaffeinate coffee and
Nonanoic acid, also called pelargonic acid, is an organic compound composed of a nine-carbon chain terminating in a carboxylic acid with structural formula CH3(CH2)7COOH. Nonanoic acid forms esters—nonanoates. It is a clear, oily liquid with an unpleasant, rancid odor. It is nearly insoluble in water, but very soluble in chloroform, ether, and hexane.
Its refractive index is 1.4322. Its critical point is at 712 K (439 °C) and 2.35 MPa.
Nonanoic acid is a fatty acid which occurs naturally as esters in the oil of pelargonium. Synthetic esters, such as methyl nonanoate, are used as flavorings.
Nonanoic acid is also used in the preparation of plasticizers and lacquers.
The derivative 4-nonanoylmorpholine is an ingredient in some pepper sprays.
The ammonium salt of nonanoic acid, ammonium nonanoate, is used as an herbicide.
Ryanodine is a poisonous alkaloid found in the South American plant Ryania speciosa (Flacourtiaceae). It was originally used as an insecticide.
The compound has extremely high affinity to the open-form ryanodine receptor, a group of calcium channels found in skeletal and heart muscle cells. It binds with such high affinity to the receptor that it was used as a label for the first purification of that class of ion channels and gave its name to it.
At nanomolar concentrations, ryanodine locks the receptor in a half-open state, whereas it fully closes them at micromolar concentration. The effect of the nanomolar-level binding is that ryanodine causes release of calcium from calcium stores in the sarcoplasmic reticulum leading to massive muscular contractions. This is true for both mammals and insects.
k-Strophanthidin is a cardenolide found in species of the genus Strophanthus. It is the aglycone of k-strophanthin, an analogue of ouabain. k-strophanthin is found in the ripe seeds of Strophanthus kombé and in the lily Convallaria.
Tribromofluoromethane or Halon 1103 or R 11B3 is a fully halogenated mixed halomethane or more exactly a bromofluorocarbon (BFC). It is a colorless liquid.
Tribromofluoromethane can be used in fire extinguishers. However, because it contains bromine, it has high ozone depletion potential (ODP) and most of the halons are banned by Montreal Protocol.
D-Erythrulose (also known as erythrulose) is a tetrose carbohydrate with the chemical formula C4H8O4. It has one ketone group and so is part of the ketose family. It is used in some self-tanning cosmetics, in general, combined with dihydroxyacetone (DHA).
Erythrulose is a natural-based keto-sugar that reacts with the amino acids in the keratin protein on the outer or dead surface layer of the skin (the stratum corneum layer of the epidermis). This nontoxic reaction produces a temporary browning effect similar to the Maillard reaction. This is not a stain or dye, but rather a chemical reaction that produces a color change on all treated skin. The reaction is similar to the browning effect seen when a cut apple slice is exposed to oxygen.
The brown color is comparable to the appearance of a UV-based suntan. Because the skin continually exfoliates itself, losing thousands of dead surface skin cells each day, the tan hue is temporary. The tan appearance lasts from two to 10 days, depending on application type and skin condition.
Erythrulose is a clear to pale-yellowish liquid, which naturally occurs in red raspberries. According to the manufacturing company, Centerchem, Inc. ,
1,2-Bis(dimethylarsino)benzene is the organoarsenic compound with the formula C6H4(As(CH3)2)2. The molecule consists of two dimethylarsino groups attached to adjacent carbon centers of a benzene ring. It is a chelating ligand in coordination chemistry. This colourless oil is commonly abbreviated "diars." Related, but non-chelating organoarsenic ligands include triphenylarsine and trimethylarsine. Work on diars led to the development of the |chelating diphosphine ligands such as dppe, which are now prevalent in homogeneous catalysis.
Diars is a bidentate ligand used in coordination chemistry. It was first described in 1939, but was popularlized by R. S. Nyholm for its ability to stabilize metal complexes with unusual oxidation states and coordination numbers, e.g. TiCl4(diars)2. High coordination numbers arise because diars is fairly compact and the As-M bonds are long, which relieves crowding at the metal center. In terms of stabilizing unusual oxidation states, diars stabilizes Ni(III), as in [NiCl2(diars)2]Cl.
Of historical interest is the supposedly diamagnetic [Ni(diars)3](ClO4)2, obtained by heating nickel perchlorate with diars. Octahedral d complexes characteristically have
Bromocresol Purple (BCP) or 5',5"-dibromo-o-cresolsulfophthalein, is a pH indicator. The most common solution is 0.04% aqueous.
Bromocresol purple has a pKa value of 6.3.
Besides its primary function as an indicator, Bromocresol Purple is used in medical laboratories to measure albumin, and as an addition to acid stop baths used in photographic processing as an indicator that the bath has reached neutral pH and needs to be replaced.
Media related to Bromocresol purple at Wikimedia Commons
Heme B or haem B (also known as protoheme IX) is the most abundant heme, both hemoglobin and myoglobin are examples of oxygen transport proteins that contain heme B. The peroxidase family of enzymes also contain heme B. The COX-1 and COX-2 enzymes (cyclooxygenase) of recent fame, also contain heme B at one of two active sites.
Generally, heme B is attached to the surrounding protein matrix (known as the apoprotein) through a single coordination bond between the heme iron and an amino-acid side-chain.
Both hemoglobin and myoglobin have a coordination bond to an evolutionarily-conserved histidine, while nitric oxide synthase and cytochrome P450 have a coordination bond to an evolutionarily-conserved cysteine bound to the iron center of heme B.
Since the iron in heme B containing proteins is bound to the four nitrogens of the porphyrin (forming a plane) and a single electron donating atom of the protein, the iron is often in a pentacoordinate state. When oxygen or the toxic carbon monoxide is bound the iron becomes hexacoordinated.
Phosphocholine is an intermediate in the synthesis of phosphatidylcholine in tissues. Phosphocholine is made in a reaction, catalyzed by choline kinase, that converts ATP + Choline into Phosphocholine and ADP. Phosphocholine is a molecule found for example in lecithin.
It is also used by nematodes and human placentas as a posttranslational modification to suppress an immune response by their hosts.
It is also one of the binding targets of C-reactive protein (CRP). Thus when a cell is damaged, CRP binds to phosphocholine beginning the recognition and phagocytotic immunologic response.
Phosphatidylcholine is one of the natural constituents of hens' eggs (and many other eggs), in the form of Egg-PC, which is often used in biomimetic membrane studies. It can be purchased in purified form from many sources. The PC group is usually divided into natural (like EggPC) and synthetic products.
Propargyl chloride, or 3-chloro-1-propyne, is a highly toxic and flammable clear brown liquid with chemical formula CHCCH2Cl. It is miscible with benzene or ethanol and insoluble in water. Its refractive index is 1.4350. Common uses for propargyl chloride include soil fumigation, corrosion prevention, and as an intermediate in organic synthesis.
It reacts with alcohols to form propargyl ethers.
Salicin is an alcoholic β-glucoside. Salicin is an anti-inflammatory agent that is produced from willow bark.
Salicin is closely related in chemical make-up to aspirin. When consumed, the acetalic etherbridge is broken down. The two parts of the molecule, glucose and the benzylic alcohol, then are metabolized separately. By oxidizing the alcohol function the aromatic part finally is metabolized to salicylic acid.
Salicin elicits bitterness like quinine, when consumed.
3'-Phosphoadenosine-5'-phosphosulfate is a derivative of adenosine monophosphate that is phosphorylated at the 3' position and has a sulfate group attached to the 5' phosphate. This anion, abbreviated PAPS, is the most common coenzyme in sulfotransferase reactions. A related anion is adenosine 5'-phosphosulfate (APS), which is not phosphorylated at the 3' position.
APS and PAPS are intermediates in the reduction of sulfate to sulfite, an exothermic conversion that is carried out by sulfate-reducing bacteria. In these organisms, sulfate serves as an electron acceptor, akin to the use of O2 as an electron acceptor by aerobic organisms. Sulfate is not reduced directly but must be activated by the formation of APS or PAPS. These carriers of activated sulfate are produced by reaction with ATP. The first reaction is catalysed by ATP sulfurase:
The conversion of APS to PAPS is catalysed by APS kinase:
Reduction of APS leads to sulfite, which is further reduced to hydrogen sulfide, which is excreted. This process is called dissimilatory sulfate reduction. Reduction of PAPS, a more elaborated sulfate ester, leads also to hydrogen sulfide. But in this case, the product is used in
β-Carotene is a strongly-coloured red-orange pigment abundant in plants and fruits. It is an organic compound and chemically is classified as a hydrocarbon and specifically as a terpenoid (isoprenoid), reflecting its derivation from isoprene units. β-Carotene is biosynthesized from geranylgeranyl pyrophosphate. It is a member of the carotenes, which are tetraterpenes, synthesized biochemically from eight isoprene units and thus having 40 carbons. Among this general class of carotenes, β-carotene is distinguished by having beta-rings at both ends of the molecule. Absorption of β-carotene is enhanced if eaten with fats, as carotenes are fat soluble.
Carotene is the substance in carrots that colours them orange and is the most common form of carotene in plants. When used as a food colouring, it has the E number E160a. The structure was deduced by Karrer et al. in 1930. In nature, β-carotene is a precursor (inactive form) to vitamin A via the action of beta-carotene 15,15'-monooxygenase. Isolation of β-carotene from fruits abundant in carotenoids is commonly done using column chromatography. The separation of β-carotene from the mixture of other carotenoids is based on the polarity of
Bromodifluoroacetyl chloride is a chemical compound with the formula BrCF2COCl. It has been used as a starting material for the synthesis of (biologically active) α,α-difluoro-γ-lactams and has been used in the synthesis of trifluoromethylated C-nucleosides.
Valerenic acid is a sesquiterpenoid constituent of the essential oil of the Valerian plant. Not to be confused with valeric acid.
Valerian is used as a herbal sedative which may be helpful in the treatment of insomnia.
The precise mechanism of this action has not been established. It is likely that several different components of the plant contribute to the effect. Valerenic acid is thought to be at least partly responsible for the sedative effects.
A study in 2004 found valerenic acid to act as a subtype-selective GABAA receptor agonist in neonatal rat brainstem preparations. The mechanism of this action could not be elucidated in this study.
A study in 2007 on GABA receptors of various composition, expressed in Xenopus oocytes (frog eggs), found valerenic acid to act mainly at α1β2 and α1β3 subtypes of these receptors. Only channels incorporating β2 or β3 subunits were stimulated by valerenic acid. Modulation of ion channel action was not significantly dependent on incorporation of α1, α2, α3 or α5 subunits.
A study in 2005, in vitro (receptor material not specified in abstract), found valerian extract as well as valerenic acid to be 5HT5A receptor (serotonin receptor) partial
Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at temperatures above 0 °C (273.15 K, 32 °F) at sea level, but it often co-exists on Earth with its solid state, ice, and gaseous state (water vapor or steam). Water also exists in a liquid crystal state near hydrophilic surfaces.
Water covers 71% of the Earth's surface, and is vital for all known forms of life. On Earth, 96.5% of the planet's water is found in oceans, 1.7% in groundwater, 1.7% in glaciers and the ice caps of Antarctica and Greenland, a small fraction in other large water bodies, and 0.001% in the air as vapor, clouds (formed of solid and liquid water particles suspended in air), and precipitation. Only 2.5% of the Earth's water is freshwater, and 98.8% of that water is in ice and groundwater. Less than 0.3% of all freshwater is in rivers, lakes, and the atmosphere, and an even smaller amount of the Earth's freshwater (0.003%) is contained within biological bodies and manufactured products.
Water on Earth moves continually through the hydrological cycle of evaporation and transpiration
4-Piperidinone is a derivative of piperidine with the molecular formula C5H9NO. 4-Piperidone is used as an intermediate in the manufacture of chemicals and pharmaceutical drugs (e.g., fentanyl).
Piperidones are a class of chemical compounds sharing the piperidone skeleton. A classic named reaction for the synthesis of piperidones is the Petrenko-Kritschenko piperidone synthesis which involves combining a alkyl-1,3-acetonedicarboxylate with benzaldehyde and an amine. This multicomponent reaction is related to the Hantzsch pyridine synthesis.
Alachlor is an herbicide from the chloroacetanilide family. Its mode of action is elongase inhibition, and inhibition of geranylgeranyl pyrophosphate (GGPP) cyclisation enzymes, part of the gibberellin pathway. It is marketed under the trade names Alanex, Bronco, Cannon, Crop Star, Intrro, Lariat, Lasso, Micro-Tech, and Partner.
It is used to control the growth of broad-leafed weeds and grasses in corn and many other crops.
It mixes well with other herbicides, and is found in mixed formulations with atrazine, glyphosate, trifluralin, and imazaquin. It is used mainly to control annual grasses and broadleaf weeds in corn (maize), soybeans, and peanuts.
It is most commonly available as microgranules containing 15% a.i., or emulsifiable concentrate containing 480 g/ litre of a.i. Homologuation in Europe requires a maximum dose of 2,400 g per hectare of a.i., or 5 litres/hectare of emulsifiable concentrate or 17 kg/ha of microgranules. The products are applied as either pre-drilling, soil incorporated, or pre-emergence.
The United States Environmental Protection Agency classifies the herbicide as toxicity class III - slightly toxic. The EPA has described the following effects when
Gyromitrin is a toxin and carcinogen present in several members of the fungal genus Gyromitra, most notably the false morel G. esculenta. It is unstable and is easily hydrolyzed to the toxic compound monomethylhydrazine, a component of some rocket fuels. Monomethylhydrazine acts on the central nervous system and interferes with the normal use and function of Vitamin B6. Poisoning results in nausea, stomach cramps, and diarrhea, while severe poisoning can result in convulsions, jaundice, or even coma or death. Exposure to monomethylhydrazine has been shown to be carcinogenic in small mammals.
Poisonings related to consumption of the false morel Gyromitra esculenta, a highly regarded fungus eaten mainly in Finland and by some in parts of Europe and North America, had been reported for at least a hundred years. Experts speculated the reaction was more of an allergic one specific to the consumer, or a misidentification, rather than innate toxicity of the fungus, due to the wide range in effects seen. Some would suffer severely or perish while others exhibited no symptoms after eating similar amounts of mushrooms from the same dish. Yet others would be poisoned after eating the fungus
Hexafluoroacetylacetone is the chemical compound with the formula CF3C(O)CH2C(O)CF3 (often abbreviated as hfac). This colourless liquid is a ligand precursor and a reagent used in MOCVD. Complexes of the conjugate base, often called Hfac, exhibit enhanced volatility and Lewis acidity relative to analogous complexes derived from acetylacetone.
This organofluorine compound was first prepared by the condensation of ethyl ester of trifluoroacetic acid and 1,1,1-trifluoroacetone. It has been investigated as an etchant for copper and its complexes, such as Cu(Hfac)(trimethylvinylsilane) have been employed as precursors in microelectronics.
Monopotassium phosphite is used primarily as a water-soluble fertilizer. It can be formed by the reaction of a potassium ion (e.g. from potassium hydroxide) with an equimolar amount of phosphorous acid.
Norbornadiene is a bicyclic, hydrocarbon and an organic compound. Norbornadiene is of interest as a metal-binding ligand, whose complexes are useful for homogeneous catalysis. It has been intensively studied owing to its high reactivity and distinctive structural property of being a diene that cannot isomerize (isomers would be anti-Bredt olefins). Norbornadiene is also a useful dienophile in Diels-Alder reactions.
Norbornadiene can be formed by a Diels-Alder reaction between a cyclopentadiene and an alkyne.
Quadricyclane, a valence isomer, can be obtained from norbornadiene by a photochemical reaction when assisted by a sensitizer such as acetophenone:
The norbornadiene-quadricyclane couple is of potential interest for solar energy storage when controlled release of the strain energy stored in quadricyclane back to norbornadiene is made possible.
Norbornadiene is reactive in cycloaddition reactions. Norbornadiene is also the starting material for the synthesis of diamantane and sumanene and it is used as an acetylene transfer agent for instance in reaction with 3,6-di-2-pyridyl-1,2,4,5-tetrazine.
Norbornadiene is a versatile ligand in organometallic chemistry, where it serves as a
Xanthine ( /ˈzænθiːn/ or /ˈzænθaɪn/; archaically xanthic acid) (3,7-dihydro-purine-2,6-dione), is a purine base found in most human body tissues and fluids and in other organisms. A number of stimulants are derived from xanthine, including caffeine and theobromine.
Xanthine is a product on the pathway of purine degradation.
Xanthine is subsequently converted to uric acid by the action of the xanthine oxidase enzyme.
Studies reported in 2008, based on C/C isotopic ratios of organic compounds found in the Murchison meteorite, suggested that xanthine and related chemicals, including the RNA component uracil, were formed extraterrestrially. In August 2011, a report, based on NASA studies with meteorites found on Earth, was published suggesting xanthine and related organic molecules, including the DNA and RNA components adenine and guanine, were made in outer space.
People with the rare genetic disorder xanthinuria lack sufficient xanthine oxidase and cannot convert xanthine to uric acid.
Derivatives of xanthine (known collectively as xanthines) are a group of alkaloids commonly used for their effects as mild stimulants and as bronchodilators, notably in the treatment of asthma
4-Aminopyridine (INN fampridine, USAN dalfampridine) is an organic compound with the chemical formula C5H4N–NH2. The molecule is one of the three isomeric amines of pyridine. It is used primarily as a research tool, in characterizing subtypes of potassium channel, and has also been used to manage some of the symptoms of multiple sclerosis, and is indicated for symptomatic improvement of walking in adults with several variations of the disease. It was undergoing Phase III clinical trials as of 2008, and the U.S. Food and Drug Administration (FDA) approved the compound on January 22, 2010. Fampridine is also marketed as Ampyra (pronounced "am-PEER-ah," according to the maker's website) in the United States by Acorda Therapeutics and as Fampyra in Europe and in Canada, where the medication has been approved for use in that country by Health Canada on February 10, 2012.
4-Aminopyridine (4-AP) is prepared by the decarbonylation of pyridine-4-carboxamide using sodium hypochlorite via the Hofmann rearrangement. The pyridine carboxamide is generated from the corresponding nitrile, which in turn is obtained from ammoxidation of 4-methylpyridine.
The largest scale industrial application of
Optochin (or ethylhydrocupreine) is a chemical used in cell culture techniques for the presumptive identification of Streptococcus pneumoniae, which is optochin-sensitive, from other alpha-hemolytic streptococci such as Streptococcus viridans which are resistant. A common mnemonic is "OVRPS" (Optochin - Viridans Resistant, Pneumoniae Sensitive).
The growth of Bacteria that are optochin sensitive will be inhibited around an optochin disc, while the growth of bacteria that are optochin resistant will not be affected. In vitro a solution of as little as 1: 10,000,000 may be inhibitory to the pneumococcus, and 1: 500,000 is bactericidal.
Strains of Streptococcus pneumoniae have been found to be resistant to optochin in laboratory testing.
Scheele's Green, also called Schloss Green, is chemically a cupric hydrogen arsenite (also called copper arsenite or acidic copper arsenite), CuHAsO3. It is a compound similar to Paris Green. It is a green pigment, of yellowish hue and was used in the past in some paints but has since fallen out of use due to its toxicity.
Scheele's Green was invented in 1775 by Carl Wilhelm Scheele. By the end of the 19th century, it virtually replaced the older green pigments based on copper carbonate.
The pigment was originally prepared by making a solution of sodium carbonate at a temperature of around 90 °C, then slowly adding in arsenious oxide, while constantly stirring until everything had dissolved. This sodium arsenite solution was then added to a copper sulfate solution. The sodium would displace the copper, which resulted in the formation of the desired product in the form of a green precipitate. This copper arsenite was then filtered off and warmed to around 43 °C to dry the crystals. To enhance the color, the salt was subsequently heated to 60-70 °C. The intensity of the color depends on the copper : arsenic ratio, which in turn was affected by ratio of the starting materials, as well
Tropinone is an alkaloid, famously synthesised in 1917 by Robert Robinson as a synthetic precursor to atropine, a scarce commodity during World War I. Tropinone and the alkaloids cocaine and atropine all share the same tropane core structure.
The first synthesis of tropinone was by Richard Willstätter in 1901. It started from the seemingly related cycloheptanone, but required many steps to introduce the nitrogen bridge; the overall yield for the synthesis path is only 0.75%. Willstätter had previously synthesized cocaine from tropinone, in what was the first synthesis and elucidation of the structure of cocaine.
The 1917 synthesis by Robinson is considered a classic in total synthesis due to its simplicity and biomimetic approach. Tropinone is a bicyclic molecule, but the reactants used in its preparation are fairly simple: succinaldehyde, methylamine and acetonedicarboxylic acid (or even acetone). The synthesis is a good example of a biomimetic reaction or biogenetic-type synthesis because biosynthesis makes use of the same building blocks. It also demonstrates a tandem reaction in a one-pot synthesis. Furthermore the yield of the synthesis was 17% and with subsequent improvements
Glucono delta-lactone (GDL) is a naturally-occurring food additive with the E number E575 used as a sequestrant, an acidifier, or a curing, pickling, or leavening agent. It is a lactone (cyclic ester) of D-gluconic acid. Pure GDL is a white odorless crystalline powder.
GDL is commonly found in honey, fruit juices, personal lubricants, and wine. GDL is neutral, but hydrolyses in water to gluconic acid which is acidic, adding a tangy taste to foods, though it has roughly a third of the sourness of citric acid. It is metabolized to glucose; one gram of GDL yields roughly the same amount of metabolic energy as one gram of sugar.
Upon addition to water, GDL is partially hydrolysed to gluconic acid, with the balance between the lactone form and the acid form established as a chemical equilibrium. The rate of hydrolysis of GDL is increased by heat and high pH.
Alginic acid, also called algin or alginate, is an anionic polysaccharide distributed widely in the cell walls of brown algae, where it, through binding water, forms a viscous gum. In extracted form it absorbs water quickly; it is capable of absorbing 200-300 times its own weight in water. Its colour ranges from white to yellowish-brown. It is sold in filamentous, granular or powdered forms.
It is a linear copolymer with homopolymeric blocks of (1-4)-linked β-D-mannuronate (M) and its C-5 epimer α-L-guluronate (G) residues, respectively, covalently linked together in different sequences or blocks.
The monomers can appear in homopolymeric blocks of consecutive G-residues (G-blocks), consecutive M-residues (M-blocks) or alternating M and G-residues (MG-blocks).
Commercial varieties of alginate are extracted from seaweed, including the giant kelp Macrocystis pyrifera, Ascophyllum nodosum, and various types of Laminaria. It is also produced by two bacterial genera Pseudomonas and Azotobacter, which played a major role in the unravelling of its biosynthesis pathway. Bacterial alginates are useful for the production of micro- or nanostructures suitable for medical applications.
Dimethylallyl pyrophosphate (or -diphosphate) (DMAPP) is an intermediate product of both mevalonic acid (MVA) pathway and DOXP/MEP pathway. It is an isomer of isopentenyl pyrophosphate (IPP) and exists in virtually all life forms. The enzyme isopentenyl pyrophosphate isomerase catalyzes the isomerization of DMAPP from IPP.
Precursor of DMAPP in the MVA pathway is mevalonic acid, and 2-C-methyl-D-erythritol-e-P in the MEP/DOXP pathway.
At present, it is believed that there is crossover between the two pathways in organisms that use both pathways to create terpenes and terpenoids, such as in plants, and that DMAPP is the crossover product.
Dimethylbenzylamine is the organic compound with the formula C6H5CH2N(CH3)2. The molecule contains the benzyl group, C6H5CH2, attached to a dimethylamino functional group. It is used as a catalyst for the formation of polyurethane foams and epoxy resins.
Like some other benzyl compounds, the molecule undergoes directed ortho metalation with butyl lithium. Because of this reaction, many derivatives are known with the formula 2-X-C6H4CH2N(CH3)2 (X = SR, PR2, etc.).
The amine is basic and undergoes quaternization with methyl iodide to give the ammonium salt [C6H5CH2N(CH3)3]I. Such salts are useful phase transfer catalysts.
Gentian violet (crystal violet, methyl violet 10B, hexamethyl pararosaniline chloride) is a bactericide and an antifungal agent, the primary agent used in the Gram stain test, perhaps the single most important bacterial identification test in use today, and it is also used by hospitals for the treatment of serious heat burns and other injuries to the skin and gums. Typically prepared as a weak (e.g. 1%) solution in water, it is painted on skin or gums to treat or prevent fungal infections. Gentian violet does not require a doctor's prescription (in the US), but is not easily found in drug stores. Tampons treated with gentian violet are sometimes used for vaginal applications.
The name "gentian violet" refers to its colour, being like that of the petals of a gentian flower; it is not made from gentians or from violets.
Gentian violet is commonly used for
In forensics, gentian violet was used to develop fingerprints. Crystal violet is also used as a tissue stain in the preparation of light microscopy sections.
In laboratory, solutions containing crystal violet and formalin are often used to simultaneously fix and stain cells grown in tissue culture to preserve them and make them
Methylcyclohexane is a colourless liquid with a faint benzene-like odour. Its molecular formula is C7H14. Methylcyclohexane is used in organic synthesis and as a solvent for cellulose ethers. It is a component of jet fuel and is also a component of correction fluids.
Monosubstituted methylcyclohexane has one methyl branch on one carbon of the cyclohexane ring. Like all substituted cyclohexanes, it can ring-flip rapidly between two chair conformations. However, a monosubstituted Methylcyclohexane exists almost exclusively in the equatorial position rather than axial. When the methyl group occupies the axial position, there is steric crowding (steric strain) by the axial hydrogens on the same side of the ring (known as the 1,3-diaxial interactions). There are two such interactions, with each methyl/hydrogen pair contributing approximately 7.61 kJ/mol strain. However, the equatorial conformation experiences no such interaction so it is more stable.
Cyclohexanes could also have more than one methyl branch. Disubstituted cyclohexane, or also known as dimethylcyclohexane has two methyl branches. Unlike the monosubstituted cyclohexane, there are several possible structures. The methyl
Mycolactone is a polyketide-derived macrolide produced and secreted by a group of very closely related pathogenic mycobacteria that have been assigned a variety of species names including, M. ulcerans, M. liflandii (an unofficial designation), M. pseudoshottsii, and some strains of M. marinum. These mycobacteria are collectively referred to as mycolactone-producing mycobacteria or MPM.
In humans, mycolactone is the toxin responsible for Buruli ulcers, doing so by damaging tissues and inhibiting the immune response.
Five distinct, naturally-occurring mycolactone structural variants have been described so far:
Mycolactone is produced by MPM through condensation of two polyketide chains (known as the core and acyl side chain). Different MPM produce characteristic mixtures of mycolactone congeners. The structural heterogeneity of mycolactones is due to variations in the acyl side chain. The structure of the mycolactone core is invariant.
The genes required for mycolactone biosynthesis form a contiguous 110-kb cluster on a large plasmid. The lactone core is produced by two polyketide synthases (PKS) that are encoded by the genes, mlsA1 and mlsA2, and a third polyketide synthase,
Terpyridine (2,2';6',2"-terpyridine) is a heterocyclic compound derived from pyridine. This colourless solid is used as a ligand in coordination chemistry.
Terpyridine was first synthesized by G. Morgan and F. H. Burstall in 1932 by the oxidative coupling of pyridines. This method, however, proceeded in low yields. In 1991, a more efficient synthesis was described that involves the condensation of 2-acetylpyridine and enaminone, which is prepared by the reaction of 2-acetylpyridine with N,N-dimethylformamide dimethyl acetal. Alternatively, the base-catalyzed reaction of 2-acetylpyridine with carbon disulfide followed by alkylation with methyl iodide gives C5H4NCOCH=C(SMe)2. Condensation of this species with 2-acetylpyridine forms the related 1,5-diketone, which condenses with ammonium acetate to form a terpyridine. Treatment of this derivative with Raney nickel remove the thioether group.
Other methods have been developed for the synthesis of terpyridine and its substituted derivatives. Substituted terpyridines are also synthesized from palladium-catalyzed cross-coupling reactions. It can be prepared from bis-triazinyl pyridine.
Terpyridine is a tridentate ligand that binds metals
Ascorbyl stearate (C24H42O7) is an ester formed from ascorbic acid and stearic acid. In addition to its use as a source of vitamin C, it is used as an antioxidant food additive in margarine (E number E305). The USDA limits its use to 0.02% individually or in conjunction with other antioxidants.
Cyromazine is a triazine insect growth regulator used as an insecticide and an acaricide. It is a cyclopropyl derivative of melamine. Cyromazine works by affecting the nervous system of the immature larval stages of certain insects.
In veterinary medicine, cyromazine is used as a ectoparasiticide.
The Food Safety and Inspection Service (FSIS) of the United States Department of Agriculture (USDA) provides a test method for analyzing cyromazine and melamine in animal tissues in its Chemistry Laboratory Guidebook which "contains test methods used by FSIS Laboratories to support the Agency's inspection program, ensuring that meat, poultry, and egg products are safe, wholesome and accurately labeled." In 1999, in a proposed rule published in the Federal Register regarding cyromazine residue, the United States Environmental Protection Agency (EPA) proposed "remov[ing] melamine, a metabolite of cyromazine from the tolerance expression since it is no longer considered a residue of concern."
Dibenzylpiperazine (DBZP) is a piperazine derivative often found as an impurity in the recreational stimulant drug benzylpiperazine (BZP).
Presence of DBZP is a marker for low quality or badly made BZP. It can be made as a reaction byproduct during BZP synthesis, either because the reaction has been run at too high a temperature, or because an excess of benzyl chloride has been used.
The toxicity of DBZP is unknown. It is not known to have any stimulant effects in its own right, although this has not been tested.
Succinic anhydride, also called dihydro-2,5-furandione, is an organic compound with the molecular formula C4H4O3. It is the acid anhydride of succinic acid.
Alkyl succinic anhydride (ASA) is used as a sizing agent or wet strength additive in paper production.
Threose is a four-carbon monosaccharide or carbohydrate with molecular formula C4H8O4. It has a terminal aldehyde group rather than a ketone in its linear chain, and so is considered part of the aldose family of monosaccharides. The threose name can be used to refer to both the D- and L-stereoisomers, and more generally to the racemic mixture (D/L-, equal parts D- and L-) as well as to the more generic threose structure (absolute stereochemistry unspecified).
The prefix "threo" which derives from threose (and "erythro" from a corresponding diastereomer erythrose) offer a useful way to describe general organic structures with adjacent chiral centers, where "the prefixes... designate the relative configuration of the centers". As is depicted in a Fischer projection of D-threose, the adjacent substituents will have a syn orientation in the isomer referred to as "threo", and are anti in the isomer referred to as "erythro".
Tryptoline, also known as tetrahydro-β-carboline and tetrahydronorharmane, is a natural organic derivative of beta-carboline. It is an alkaloid chemically related to tryptamines. Derivatives of tryptoline have a variety of pharmacological properties and are known collectively as tryptolines.
Many tryptolines are competitive selective inhibitors of the enzyme monoamine oxidase type A (MAO-A). 5-Hydroxytryptoline and 5-methoxytryptoline are the most active monoamine oxidase inhibitors (MAOIs) with IC50s of 0.5 μM and 1.5 μM respectively, using 5-hydroxytryptamine (serotonin) as substrate.
Tryptolines are also potent reuptake inhibitors of serotonin and epinephrine, with a significantly greater selectivity for serotonin. Comparison of the inhibition kinetics of tetrahydro-β-carbolines for serotonin and epinephrine reuptake to that of the platelet aggregation response to these amines has shown that 5-hydroxymethtryptoline, methtryptoline, and tryptoline are poor inhibitors of reuptake. In all respects 5-hydroxytryptoline and 5-methoxytryptoline showed greater pharmacological activity than the tryptoline and methtryptoline.
Although the in vivo formation of tryptolines has been a matter
Norfenfluramine, or 3-trifluoromethylamphetamine, is a drug of the amphetamine family which behaves as a serotonin and norepinephrine releasing agent and potent 5-HT2A, 5-HT2B, and 5-HT2C agonist. The action of norfenfluramine on 5-HT2B receptors on heart valves leads to a characteristic pattern of heart failure following proliferation of cardiac fibroblasts on the tricuspid valve, known as cardiac fibrosis. This side effect led to the withdrawal of fenfluramine as an anorectic agent worldwide, and to the withdrawal of benfluorex in Europe, as both fenfluramine and benfluorex form norfenfluramine as an active metabolite.
Barbituric acid or malonylurea or 6-hydroxyuracil is an organic compound based on a pyrimidine heterocyclic skeleton. It is an odorless powder soluble in water. Barbituric acid is the parent compound of barbiturate drugs, although barbituric acid itself is not pharmacologically active. The compound was discovered by the German chemist Adolf von Baeyer on December 4, 1864, the feast of Saint Barbara (who gave the compound its namesake), by combining urea and malonic acid in a condensation reaction. Malonic acid has since been replaced by diethyl malonate, as using the ester avoids the problem of having to deal with the acidity of the carboxylic acid and its unreactive carboxylate.
The α-carbon has a reactive hydrogen atom and is quite acidic (pKa = 4.01) even for a diketone species (cf. dimedone with pKa 5.23 and acetylacetone with pKa 8.95) because of the additional aromatic stabilisation of the carbanion. Using the Knoevenagel condensation reaction, barbituric acid can form a large variety of barbiturate drugs that behave as central nervous system depressants.
Barbituric acid is used in synthesis of riboflavin.
As of 2007, more than 2550 barbiturates and related compounds have
Histamine is an organic nitrogen compound involved in local immune responses as well as regulating physiological function in the gut and acting as a neurotransmitter. Histamine triggers the inflammatory response. As part of an immune response to foreign pathogens, histamine is produced by basophils and by mast cells found in nearby connective tissues. Histamine increases the permeability of the capillaries to white blood cells and some proteins, to allow them to engage pathogens in the infected tissues.
Histamine forms colorless hygroscopic crystals that melt at 84°C, and are easily dissolved in water or ethanol, but not in ether. In aqueous solution histamine exists in two tautomeric forms, N-H-histamine and N-H-histamine. The imidazole ring has two nitrogens. The nitrogen farthest away from the side chain is the 'tele' nitrogen and is denoted by a lowercase tau sign. The nitrogen closest to the side chain is the 'pros' nitrogen and is denoted by the pi sign. Whichever position the nitrogen, which has the hydrogen on it, is in, is how the tautomer is named. If the nitrogen with the hydrogen is in the tele position, then histamine is in the tele-tautomer form. The tele-tautomer is
Oleuropein is a chemical compound found in olive leaf from the olive tree together with other closely related compounds such as 10-hydroxyoleuropein, ligstroside, and 10-hydroxyligstroside. All these compounds are tyrosol esters of elenolic acid that are further hydroxylated and glycosylated. It is one of the main natural phenols found in argan oil. It is also found in the leaves of privet.
Oleuropein and its metabolite hydroxytyrosol have powerful antioxidant activity both in vivo and in vitro and give extra-virgin olive oil its bitter, pungent taste. Oleuropein preparations have been claimed for several pharmacological effects among them strengthening of the immune system. A study in rats suggests oleuropein enhances thermogenesis by increasing the thermogenin content in brown adipose tissue and the secretion of noradrenaline and adrenaline.
Pivalic acid is a carboxylic acid with a molecular formula of (CH3)3CCO2H. This colourless, odiferous organic compound is solid at room temperature.
Pivalic acid is prepared by “hydrocarboxylation” of isobutene via the Koch reaction:
Such reactions require an acid catalyst such as hydrogen fluoride. tert-Butyl alcohol and isobutyl alcohol can also be used in place of isobutene. Globally, several million kilograms are produced annually.
It was originally prepared by the oxidation of pinacolone with chromic acid and by the hydrolysis of tert-butyl cyanide. Convenient laboratory routes proceed via t-butyl chloride via carbonation of the Grignard reagent and by oxidation of pinacalone.
Relative to esters of most carboxylic acids, esters of pivalic acid are unusually resistant to hydrolysis. Some applications result from this thermal stability. Polymers derived from pivalate esters of vinyl alcohol are highly reflective lacquers. The pivaloyl (abbreviated piv or pv) group is a protective group for alcohols in organic synthesis.
Like most carboxylic acids pivalic acid is a mild irritant and only weakly toxic (oral LD50 = 900 mg/kg for rats).
Policresulen is a topical haemostatic and antiseptic. It is indicated for common anal disorders, such as hemorrhoids, and for gynecological infections. In some countries it is marketed under the trade name Albothyl or Polilen (Taiwan) or Faktu (combination with Cinchocaine).
Setiptiline (Tecipul), also known as teciptiline, is a tetracyclic antidepressant (TeCA) which acts as a noradrenergic and specific serotonergic antidepressant (NaSSA). It was launched in 1989 for the treatment of depression in Japan by Mochida.
Setiptiline has a tetracyclic structure and is a close analogue of mianserin and mirtazapine, with setiptiline being delta(13b,4a),4a-carba-mianserin, and mirtazapine being 6-aza-mianserin.
Setiptiline acts as a norepinephrine reuptake inhibitor, α2-adrenergic receptor antagonist, and serotonin receptor antagonist, likely at the 5-HT2A, 5-HT2C, and/or 5-HT3 subtypes, as well as an H1 receptor inverse agonist/antihistamine.
Tetrahydrobiopterin (BH4, THB, trade name Kuvan) or sapropterin (INN) is a naturally occurring essential cofactor of the three aromatic amino acid hydroxylase enzymes, used in the degradation of amino acid phenylalanine and in the biosynthesis of the neurotransmitters serotonin (5-hydroxytryptamine, 5-HT), melatonin, dopamine, norepinephrine (noradrenaline), epinephrine (adrenaline), and is a cofactor for the production of nitric oxide (NO) by the nitric oxide synthases.
Tetrahydrobiopterin was discovered to play a role as an enzymatic cofactor. The first enzyme found to use tetrahydrobiopterin is phenylalanine hydroxylase (PAH).
Tetrahydrobiopterin is biosynthesized from guanosine triphosphate (GTP) by three chemical reactions mediated by the enzymes GTP cyclohydrolase I (GTPCH), 6-pyruvoyltetrahydropterin synthase (PTPS), and sepiapterin reductase (SR).
Tetrahydrobiopterin has the following responsibilities as a cofactor:
Tetrahydrobiopterin has multiple roles in human biochemistry. One is to convert amino acids such as phenylalanine, tyrosine, and tryptophan to precursors of dopamine and serotonin, the body's primary neurotransmitters). Due to its role in the conversion of
Morphine-6-glucuronide (M6G) is a major active metabolite of morphine, and as such is the molecule responsible for much of the pain-relieving effects of morphine (and thus heroin). M6G is formed from morphine by the enzyme UDP-Glucuronosyltransferase-2B7 (UGT2B7). M6G can accumulate to toxic levels in kidney failure.
The μ-opioid receptor subtype 3 appears to be activated (agonized) by morphine-6β-glucuronide but not morphine itself. This finding is also true of certain heroin metabolites (6-MAM) but not heroin proper.
This analgesic activity of M6G (in animals) was first noted by Yoshimura.
Subsequent work at St Bartholomew's Hospital, London in the 1980s, using a sensitive and specific HPLC assay, accurately defined for the first time the metabolism of morphine, and the abundance of this metabolite (along with morphine-3-glucuronide, considered an inactive metabolite).
It was postulated that renal impairment would result in accumulation of the renally-excreted active agent M6G, leading to potentially fatal toxicity such as respiratory depression. The frequent use of morphine in critically ill patients, and the common occurrence of renal failure in this group implied that M6G
N-Acetylgalactosamine (GalNAc), is an amino sugar derivative of galactose.
In humans it is the terminal carbohydrate forming the antigen of blood group A.
It is typically the first monosaccharide that connects serine or threonine in particular forms of protein O-glycosylation.
N-Acetylgalactosamine is necessary for intercellular communication, and is concentrated in sensory nerve structures of both humans and animals.
1,3-Dichloropropene, sold under diverse trade names, is an organochlorine compound. It is colorless liquid with a sweet smell. It dissolves in water and evaporates easily. It is used mainly in farming as a pesticide, specifically as a preplant fumigant and nematicide. It is widely used in the US and other countries, but is in the process of being phased out in the European Union.
It is a byproduct in the chlorination of propene to make allyl chloride.
It is usually obtained as a mixture of the geometric isomers, called Z-1,3-dichloropropene, and E-1,3-dichloropropene. Although it was first applied in agriculture in the 1950's, at least two biodegradation pathways have evolved. One pathway degrades the chlorocarbon to acetaldehyde via chloroacrylic acid.
The TLV-TWA for 1,3-dichloropropene (DCP) is 1 ppm. It is a contact irritant. A wide range of complications have been reported.
Evidence for the carcinogenicity of 1,3-dichloropropene in humans is inadequate, but results from several cancer bioassays provide adequate evidence of carcinogenicity in animals. In the US, the Department of Health and Human Services (DHHS) has determined that 1,3-dichloropropene may reasonably be
Alcian blue (AB), also called Alcian blue 8GX, Ingrain blue 1, and C.I. 74240, is a copper phthalocyanine, first synthesized by the ICI dyestuffs department under N. H. Haddock in 1947, originally as a textile dye. The dye stains acid mucopolysaccharides and glycosaminoglycans, for which it is one of the most widely used cationic dyes; the stained parts are blue to bluish-green. It can be combined with H&E staining and van Gieson staining methods. It bonds by electrostatic forces with the negatively charged macromolecules. Gradual increases in the electrolyte concentration used to wash the bound dye selectively identifies neutral, sulphated, and phosphated mucopolysaccharides.
Phosphocreatine, also known as creatine phosphate or PCr (Pcr), is a phosphorylated creatine molecule that serves as a rapidly mobilizable reserve of high-energy phosphates in skeletal muscle and the brain.
Phosphocreatine is formed from parts of three amino acids: arginine (Arg), glycine (Gly), and methionine (Met). It can be synthesized by formation of guanidinoacetate from Arg and Gly (in kidney) followed by methylation (S-adenosyl methionine is required) to creatine (in liver), and phosphorylation by creatine kinase (ATP is required) to phosphocreatine (in muscle); catabolism: dehydration to form the cyclic Schiff base creatinine. Phosphocreatine is synthesized in the liver and transported to the muscle cells, via the bloodstream, for storage.
The creatine phosphate shuttle facilitates transport of high energy phosphate from mitochondria.
Phosphocreatine can anaerobically donate a phosphate group to ADP to form ATP during the first 2 to 7 seconds following an intense muscular or neuronal effort. Conversely, excess ATP can be used during a period of low effort to convert creatine to phosphocreatine. The reversible phosphorylation of creatine (i.e., both the forward and backward
Spiperone (Spiroperidol, Spiropitan) is a psychoactive drug and research chemical belonging to the butyrophenone chemical class. It functions as a 5-HT1A, 5-HT2A, 5-HT7, and D2 receptor antagonist, and has been used to identify these receptors when labeled with tritium. It has negligible affinity for the 5-HT2C receptor. Additionally, spiperone was identified by compound screening to be an activator of Ca activated Cl channels (CaCCs), thus a potential target for therapy of cystic fibrosis.
N-Methylspiperone (NMSP) is a derivate of spiperone that is used to study the dopamine and serotonin neurotransmitter system. Labeled with the radioisotope carbon-11, it can be used for positron emission tomography.
Succinyl-Coenzyme A, abbreviated as Succinyl-CoA or SucCoA, is a combination of succinic acid and coenzyme A.
It is an important intermediate in the citric acid cycle, where it is synthesized from α-Ketoglutarate by α-ketoglutarate dehydrogenase through decarboxylation. During the process, coenzyme A is added.
It is also synthesized from propionyl CoA, the odd-numbered fatty acid, which cannot undergo beta-oxidation. Propionyl-CoA is carboxylated to D-methylmalonyl-CoA, isomerized to L-methylmalonyl-CoA, and rearranged to yield succinyl-CoA via a vitamin B12-dependent enzyme. Succinyl-CoA is an intermediate of the citric acid cycle and can be readily incorporated there.
It is converted into succinate through the hydrolytic release of coenzyme A by succinyl-CoA synthetase (succinate thiokinase).
Another fate of succinyl-CoA is porphyrin synthesis, where succinyl-CoA and glycine are combined by ALA synthase to form δ-aminolevulinic acid (dALA).
Succinyl CoA can be formed from methylmalonyl CoA through the utilization of deoxyadenosyl-B12 (deoxyadenosylcobalamin) by the enzyme methylmalonyl-CoA mutase. This reaction, which requires vitamin B12 as a cofactor, is important in the
Valencene is a sesquiterpene that is an aroma component of citrus fruit and citrus-derived odorants. It is cheaply obtained from Valencia oranges. Valencene is biosynthesized from FPP by the CVS enzyme.
It is a precursor to nootkatone, the main contributor to the aroma and flavor of grapefruit.
5-Formiminotetrahydrofolate is an intermediate in the catabolism of histidine. It is produced by glutamate formimidoyltransferase and then converted into 5,10-methenyltetrahydrofolate by formiminotransferase cyclodeaminase.
Calcium nitride is a red-brown, crystalline solid made up of calcium and nitrogen. Its chemical formula is Ca3N2. α-Calcium nitride is the commonly encountered form. It has an anti-bixbyite structure similar to Mn2O3, except that the positions of the ions are reversed: calcium (Ca) take the oxide (O) positions and nitride ions (N) the manganese (Mn).
Calcium nitride is formed along with the oxide, CaO, when calcium burns in air. It can be produced by direct reaction of the elements:
It reacts with moisture in air to give ammonia and calcium hydroxide:
This reaction also occurs in water.
It absorbs hydrogen above 350 °C:
Glyceraldehyde 3-phosphate, also known as triose phosphate or 3-phosphoglyceraldehyde and abbreviated as G3P, GADP, GAP, TP, GALP or PGAL, is a chemical compound that occurs as an intermediate in several central metabolic pathways of all organisms. It is a phosphate ester of the 3-carbon sugar glyceraldehyde and has chemical formula C3H7O6P.
The CAS number of glyceraldehyde 3-phosphate is 591-59-3 and that of D-glyceraldehyde 3-phosphate (one of the two optical isomers of the compound and the one most often occurring in living organisms) is 591-57-1.
D-glyceraldehyde 3-phosphate is formed from the following three compounds in reversible reactions:
Compound C05378 at KEGG Pathway Database. Enzyme 22.214.171.124 at KEGG Pathway Database. Compound C00111 at KEGG Pathway Database. Compound C00118 at KEGG Pathway Database.
The numbering of the carbon atoms indicates the fate of the carbons according to their position in fructose 6-phosphate.
Compound C00111 at KEGG Pathway Database.Enzyme 126.96.36.199 at KEGG Pathway Database.Compound C00118 at KEGG Pathway Database.
Compound C00118 at KEGG Pathway Database. Enzyme 188.8.131.52 at KEGG Pathway Database. Reaction R01063 at KEGG Pathway Database.
N-Acetylserotonin (NAS), also known as normelatonin, is a naturally occurring chemical intermediate in the endogenous production of melatonin from serotonin. It is produced from serotonin by the enzyme aralkylamine N-acetyltransferase (AANAT) and is converted to melatonin by acetylserotonin O-methyltransferase (ASMT). Like melatonin, NAS is an agonist at the melatonin receptors MT1, MT2, and MT3, and may be considered to be a neurotransmitter. In addition, NAS is distributed in some areas of the brain where serotonin and melatonin are not, suggesting that it may have unique central duties of its own instead of merely functioning as a precursor in the synthesis of melatonin.
Recently, NAS has been shown to act as a potent TrkB receptor agonist, while serotonin and melatonin are not. It produces robust antidepressant, neuroprotective, and neurotrophic effects that are TrkB-mediated. In addition, AANAT knockout mice which lack NAS display significantly greater immobility times versus control mice in assays of depression like the forced swim test.
NAS may also play a major role in the antidepressant effects of selective serotonin reuptake inhibitors (SSRIs) and monoamine oxidase
Betazole is a histamine H2 receptor agonist. Also known as Ametazole. Betazole hydrochloride is known as gastramine and histalog.
It has been used as a gastric stimulant to test for maximal production of gastric secretion activity The test can be used in diagnosis of diseases such as Zollinger-Ellison syndrome where there is excess acid production, in this case driven by over production of gastrin. The volume of acid secretion is measured following administration of betazole, diagnosis being secretion greater than 60% of the maximal acid secretion following betazole stimulation. This procedure can lead to complications and should be avoided in subjects with coronary artery disease It is also used in diagnosis of gastritis in association with a test for secretin activity
Betazole is used as a stimulant in preference to histamine because of its specificity for the H2 receptor and its advantage of not generating the undesirable side effects that histamine would induce. It therefore does not require concomitant use of antihistaminic compounds to block the actions of histamine at other histamine receptor types.
Its action in stimulating histamine release can be of use when testing the
Deoxyadenosine monophosphate, also known as deoxyadenylate, or dAMP, is a derivative of the common nucleic acid AMP, or adenosine monophosphate, in which the -OH (hydroxyl) group on the 2' carbon on the nucleotide's pentose has been reduced to just a hydrogen atom (hence the "deoxy-" part of the name). Deoxyadenosine monophosphate is abbreviated dAMP. It is a monomer used in DNA.
Butylparaben, or butyl paraben, is a member of the paraben family, which has the formula C4H9(C6H4(OH)COO). It is used as an antimicrobial preservative in cosmetics such as eye shadow, foundation, sunscreen, facial moisturizer and skin anti-aging treatment. It is also used in medication suspensions, and as a flavoring additive in food. Butylparaben and the paraben family have come to public attention recently, due to a study reporting low concentrations of parabens in breast tumors, around 20.6±4.2 ng/g tissue. However, parabens have not been proven to cause breast cancer. Estimates by the U.S. Food and Drug Administration and the Center for Food Safety and Applied Nutrition have found that the average person is exposed to about 37 ng of butylparaben per day.
Butylparaben is a fine, colorless, odorless, crystalline solid at room temperature. The molecular formula of butylparaben undergoes hydrolysis to its corresponding carboxylic acid in basic solutions. The antimicrobial activity of parabens increases with increasing alkyl chain length (methylparaben
Massoia lactone is an alkyl lactone derived from the bark of the Massoia tree (Cryptocaria massoia) which is found in Papua, Indonesia though the compound can also be found as a component of cane sugar molasses, cured tobacco and the essential oil of Sweet Osmanthus (Osmanthus fragrans).
Once widely used as a natural coconut flavouring, natural massoia lactone has been largely superseded by a synthetic alternative because the extraction process is expensive and the tree is killed during the process of removing the bark.
Massoia lactone has an odour that is described as sweet, coconut meat, lactonic, creamy, milky and waxy and, at a dilution of 20 ppm, a taste described as creamy, coconut, green and slightly fruity.
Mesoxalic acid, also called oxomalonic acid or ketomalonic acid, is an organic compound with formula C3H2O5 or HO-(C=O)3-OH.
Mesoxalic acid is both a dicarboxylic acid and a ketonic acid. It readily loses two protons to yield the divalent anion C3O5, called mesoxalate, oxomalonate, or ketomalonate. These terms are also used for salts containing this anion, such as sodium mesoxalate, Na2C3O5); and for esters containing the -C3O5- or -O-(C=O)3-O- moiety, such as diethyl mesoxalate, C2H5)2C3O5. Mesoxalate is one of the oxocarbon anions, which (like carbonate CO3 and oxalate C2O4) consist solely of carbon and oxygen.
Mesoxalic acid readily absorbs and reacts with water to form a product commonly called "mesoxalic acid (mono)hydrate", more properly dihydroxymalonic acid, HO-(C=O)-C(OH)2-(C=O)-OH. In product catalogs and other contexts, the terms "mesoxalic acid", "oxomalonic acid", etc. often refer to this "hydrated" compound. In particular, the product traded as "sodium mesoxalate monohydrate" is almost always sodium dihydroxymalonate.
Mesoxalic acid can be obtained synthetically by hydrolysis of alloxan with baryta water, by warming caffuric acid with lead acetate solution, or from
Ovalene is a polycyclic aromatic hydrocarbon with the formula C32H14, which consists of ten peri-fused six-membered rings. It is very similar to coronene.
Ovalene is a reddish-orange compound. It is sparingly soluble in solvents such as benzene, toluene, and dichloromethane. Its solutions have a green fluorescence under UV light.
Ovalene has been shown to form in deep-sea hydrothermal vent areas and in the hydrocracking process of petroleum refining.
Pristanic acid (2,6,10,14-tetramethylpentadecanoic acid) is a terpenoid acid present at micromolar concentrations in the blood plasma of healthy individuals. It is also found in the lipids from many sources such as freshwater sponges, krill, earthworms, whales, human milk fat, bovine depot fat, butterfat or Californian petroleum. It is usually present in combination with phytanic acid. In humans, pristanic acid is obtained from two sources: either directly from the diet or as the alpha oxidation product of phytanic acid. At physiological concentrations pristanic acid is a natural ligand for PPARα. In liver, pristanic acid is degraded by peroxisomal beta oxidation to propionyl-CoA. Together with phytanic acid, pristanic acid accumulates in several inherited disorders such as Zellweger syndrome.
Pristanic acid was first isolated from butterfat by R. P. Hansen and J. D. Morrison in 1964. The name of the substance is derived from pristane (2,6,10,14-tetramethylpentadecane), the corresponding hydrocarbon. Pristane was isolated from shark liver and was named after Latin pristis, "shark".
Sphingosine-1-phosphate (S1P) is a signaling sphingolipid. It is also referred to as a bioactive lipid mediator. Sphingolipids at large form a class of lipids characterized by a particular aliphatic aminoalcohol, which is sphingosine.
Sphingosine can be released from ceramides, a process catalyzed by the enzyme ceramidase. Phosphorylation of sphingosine is catalyzed by sphingosine kinase, an enzyme ubiquitously found in the cytosol and endoplasmatic reticulum of various types of cells. S1P can be dephosphorylated to sphingosine by sphingosine phosphatases and can be irreversibly degraded by an enzyme, Sphingosine phosphate lyase.
S1P is a blood borne lipid mediator, in particular in association with lipoproteins such as high density lipoprotein (HDL). It is less abundant in tissue fluids. This is referred to as the S1P gradient, which seems to have biological significance in immune cell trafficking.
Originally thought as an intracellular second messenger, it was discovered to be an extracellular ligand for G protein-coupled receptor S1PR1 in 1998. It is now known that S1P receptors are members of the Lysophospholipid receptor family. There are five described to date. Most of the
Sulfanilic acid (4-aminobenzenesulfonic acid ) is an off-white crystalline solid which finds application in quantitative analysis of nitrate and nitrite ions. The solid acid exists as a zwitterion, and has an unusually high melting point.
Sulfanilic acid can be produced by sulfonation of aniline:
As the compound readily form diazo compounds, it is used to make dyes and sulpha drugs. This property is also used for the quantitative analysis of nitrate and nitrite ions by diazonium coupling reaction with N-(1-Naphthyl)ethylenediamine, resulting in an azo dye, and the concentration of nitrate or nitrite ions were deduced from the color intensity of the resulting red solution by colorimetry.
It is also used as a standard in combustion analysis.
4-Aminobenzoic acid (also known as para-aminobenzoic acid or PABA because the number 4 carbon in the benzene ring is also known as the para position) is an organic compound with the formula H2NC6H4CO2H. PABA is a white grey crystalline substance that is only slightly soluble in water. It consists of a benzene ring substituted with an amino group and a carboxyl group.
In industry, PABA is prepared mainly by two routes: reduction of 4-nitrobenzoic acid and the Hoffman degradation of the monoamide derived from terephthalic acid.
Food sources of PABA include liver, brewer's yeast (and unfiltered beer), kidney, molasses, mushrooms, and whole grains.
PABA is an intermediate in the bacterial synthesis of folate. PABA has been referred to as Vitamin Bx. Some bacteria in the human intestinal tract such as E. coli generate PABA from chorismate. Humans lack the enzymes to convert PABA to folate, and therefore require folate from dietary sources such as green leafy vegetables. Although some intestinal bacteria can synthesize folate from PABA and some E. coli can synthesize folate, this requires six enzymatic activities in folate synthesis which are not all done in the same bacteria. In humans
Asarone, which includes alpha (trans) and beta (cis) types, is an ether found in certain plants such as acorus and asarum. As a volatile fragrance oil, it is used in killing plant fungal pests and bacteria. The toxicity and carcinogenicity of asarone means that it may be difficult to develop practical anthelmintics and insecticides based on it.
The main clinical symptom of asarone is prolonged vomiting that sometimes lasted more than 15 hours. Asarone is not metabolized to trimethoxyamphetamine as has been claimed by online vendors. Beta-asarone may be a potential candidate for development as a therapeutic agent to manage cognitive impairment associated with conditions such as Alzheimer's disease.
A cyanide is a chemical compound that contains the cyano group, -C≡N, which consists of a carbon atom triple-bonded to a nitrogen atom. Cyanides most commonly refer to salts of the anion CN, which is isoelectronic with carbon monoxide and with molecular nitrogen. Most cyanides are highly toxic.
In IUPAC nomenclature, organic compounds that have a –C≡N functional group are called nitriles. Thus, nitriles are organic compounds. An example of a nitrile is CH3CN, acetonitrile, also known as methyl cyanide. Nitriles usually do not release cyanide ions. A functional group with a hydroxyl and cyanide bonded to the same carbon is called cyanohydrin. Unlike nitriles, cyanohydridins do release hydrogen cyanide. In inorganic chemistry, salts containing the C≡N ion are referred to as cyanides.
Cyanides are produced by certain bacteria, fungi, and algae and are found in a number of plants. Cyanides are found, although in small amounts, in certain seeds and fruit stones, e.g., those of apple, mango, peach, and bitter almonds. In plants, cyanides are usually bound to sugar molecules in the form of cyanogenic glycosides and defend the plant against herbivores. Cassava roots (also called manioc),
Cyclic guanosine monophosphate (cGMP) is a cyclic nucleotide derived from guanosine triphosphate (GTP). cGMP acts as a second messenger much like cyclic AMP. Its most likely mechanism of action is activation of intracellular protein kinases in response to the binding of membrane-impermeable peptide hormones to the external cell surface.
Guanylate cyclase (GC) catalyzes cGMP synthesis. This enzyme converts GTP to cGMP. In turn, peptide hormones such as the atrial natriuretic factor activate membrane-bound GC, while soluble GC is typically activated by nitric oxide to stimulate cGMP synthesis.
cGMP is a common regulator of ion channel conductance, glycogenolysis, and cellular apoptosis. It also relaxes smooth muscle tissues. In blood vessels, relaxation of vascular smooth muscles lead to vasodilation and increased blood flow.
cGMP is a secondary messenger in phototransduction in the eye. In the photoreceptors of the mammalian eye, the presence of light activates phosphodiesterase, which degrades cGMP. The sodium ion channels in photoreceptors are cGMP-gated, so degradation of cGMP causes sodium channels to close, which leads to the hyperpolarization of the photoreceptor's plasma
Methoxychlor is a synthetic organochlorine used as an insecticide.
Methoxychlor is used to protect crops, ornamentals, livestock, and pets against fleas, mosquitoes, cockroaches, and other insects. It was intended to be a replacement for DDT, but has since been banned based on its acute toxicity, bioaccumulation, and endocrine disruption activity .
The amount of methoxychlor in the environment changes seasonally due to its use in farming and foresting. It does not dissolve readily in water, so it is mixed with a petroleum-based fluid and sprayed, or used as a dust. Sprayed methoxychlor settles on the ground or in aquatic ecosystems, where it can be found in sediments. Its degradation may take many months. Methoxychlor is ingested and absorbed by living organisms, and it accumulates in the food chain. Some metabolites may have unwanted side effects.
The use of methoxychlor as a pesticide was banned in the United States in 2003 and in the European Union in 2002.
Human exposure to methoxychlor occurs via air, soil, and water, primarily in people who work with the substance or who are exposed to air, soil, or water that has been contaminated. It is unknown how quickly and efficiently
N-Acetylaspartic acid, or N-acetylaspartate (NAA), is a derivative of aspartic acid with a formula of C6H9NO5 and a molecular weight of 175.139.
NAA is the second-most-concentrated molecule in the brain after the amino acid glutamate. It is detected in the adult brains only in neurons synthesized in the mitochondria of neurons from the amino acid aspartic acid and acetyl-coenzyme A. The various functions served by NAA are still under investigation, but the primary proposed functions include its being:
In the brain, NAA is thought to be present predominantly in neuronal cell bodies, where it acts as a neuronal marker. NAA gives off the largest signal in magnetic resonance spectroscopy of the human brain, and the levels measured there are decreased in numerous neuropathological conditions ranging from brain injury to stroke to Alzheimer's disease. This fact makes NAA a reliable diagnostic molecule for doctors treating patients with brain damage or disease.
NAA may also be a marker of creativity.
N-Acetylmannosamine is a monosaccharide involved in a range of metabolic processes. It is an amino sugar/amino acid that consists of neuraminic acids, glycolipids and glycoproteins, and is used for the synthesis of sialic acid.
Omethoate (C5H12NO4PS) is a systemic organophosphorous insecticide and acaricide available as a soluble concentrate. It is used to control insects and mites in horticulture and agriculture, as well as in the home garden.
It is an irritant to the skin and mucous membranes. Omethoate is known to be fatal or debilitating to species of chicken, rat, and crops.
Its toxicity and hazard potential are still under review because of concerns about its safety.
Tetrodotoxin, frequently abbreviated as TTX, is a potent neurotoxin with no known antidote. There have been successful tests of a possible antidote in mice, but further tests must be carried out to determine efficacy in humans. Fampridine has been shown to reverse tetrodotoxin toxicity in animal experiments.
Tetrodotoxin blocks action potentials in nerves by binding to the voltage-gated, fast sodium channels in nerve cell membranes, essentially preventing any affected nerve cells from firing by blocking the channels used in the process. The binding site of this toxin is located at the pore opening of the voltage-gated Na channel. Its name derives from Tetraodontiformes, the name of the order that includes the pufferfish, porcupinefish, ocean sunfish or mola, and triggerfish, several species of which carry the toxin. Although tetrodotoxin was discovered in these fish and found in several other animals (e.g., blue-ringed octopus, rough-skinned newt, and Naticidae) it is actually produced by certain symbiotic bacteria, such as Pseudoalteromonas tetraodonis, certain species of Pseudomonas and Vibrio, as well as some others that reside within these animals.
Its mechanism of action,
Butyric acid (from Greek βούτυρο, meaning "butter"), also known under the systematic name butanoic acid, is a carboxylic acid with the structural formula CH3CH2CH2-COOH. Salts and esters of butyric acid are known as butyrates or butanoates. Butyric acid is found in milk, especially goat, sheep and buffalo's milk, butter, Parmesan cheese, and as a product of anaerobic fermentation (including in the colon and as body odor). It has an unpleasant smell and acrid taste, with a sweetish aftertaste (similar to ether). It can be detected by mammals with good scent detection abilities (such as dogs) at 10 ppb, whereas humans can detect it in concentrations above 10 ppm.
Butyric acid was first observed (in impure form) in 1814 by the French chemist Michel Eugène Chevreul. By 1818, he had purified it sufficiently to characterize it. The name of butyric acid comes from the Latin word for butter, butyrum (or buturum), the substance in which butyric acid was first found.
Butyric acid is a fatty acid occurring in the form of esters in animal fats. The triglyceride of butyric acid makes up 3% to 4% of butter. When butter goes rancid, butyric acid is liberated from the glyceride by hydrolysis,
CGS-21680 is a specific adenosine A2A subtype receptor agonist. It is usually presented as an organic hydrochloride salt with a molecular weight of 536.0 g/M. It is soluble up to 3.4 mg/mL in DMSO and 20 mg/mL in 45% (w/v) aq 2-hydroxypropyl-β-cyclodextrin.
The chemical is currently used by researchers interested in studying neuronal transmission with a high-affinity, subtype specific analogue for adenosine. This includes research in respiration where it is believed that A2A receptors are involved in rhythm generation in the pre-Bötzinger complex. The drug is not currently approved for use in a therapeutic capacity.
Diquat is a contact herbicide that produces desiccation and defoliation most often available as the dibromide, diquat dibromide. Brand names for this formulation include Aquacide, Dextrone, Preeglone, Deiquat, Detrone, Reglone, Reglon, Reglox, Ortho-Diquat and Weedtrine-D.
Diquat is a non-selective herbicide that acts quickly to damage only those parts of the plant to which it is applied. It bonds strongly to mineral and organic particles in soil and water where it remains without significant degradation for years. However, bound to clays diquat is biologically inactive at concentrations typically observed in agricultural soils.
Diquat dibromide is moderately toxic. It may be fatal to humans if swallowed, inhaled, or absorbed through the skin in sufficient quantities.
Pyridine is oxidatively coupled to 2,2'-bipyridine over a heated Raney nickel catalyst. The ethylene bridge is formed by the reaction with 1,2-dibromoethane:
DNQX (6,7-dinitroquinoxaline-2,3-dione) is an AMPA and Kainate receptor antagonist. It is used in a variety of molecular biology subfields, notably neurophysiology, to assist researchers in determining the properties of various types of ion channels.
Glucuronolactone is a naturally occurring chemical that is an important structural component of nearly all connective tissues. Glucuronolactone is also found in many plant gums.
Glucuronolactone is a white solid odorless compound, soluble in hot and cold water. Its melting point ranges from 176 to 178 °C. The compound can exist in a monocyclic aldehyde form or in a bicyclic hemiacetal (lactol) form.
Glucuronolactone has received some notoriety due to urban legends that it was a Vietnam War-era drug manufactured by the American government. The rumor goes on to say that it was banned due to brain tumor-related deaths. The rumor has since been proven false, as neither the cited British Medical Journal article nor the "banning of its consumption" ever occurred. Furthermore, no warnings appear on the Food and Drug Administration website regarding its potential to cause brain tumors or other maladies.
Glucuronolactone is rapidly absorbed and metabolized into non-toxic metabolites such as xylulose. In addition, humans may be able to use glucuronolactone as a precursor for ascorbic acid synthesis. According to The Merck Index, it is also used as a detoxicant.
Glucuronolactone is a popular
Propane is a three-carbon alkane with the molecular formula C3H8, normally a gas, but compressible to a transportable liquid. A by-product of natural gas processing and petroleum refining, it is commonly used as a fuel for engines, oxy-gas torches, barbecues, portable stoves, and residential central heating. Propane is one of a group of liquefied petroleum gases. The others include butane, propylene, butadiene, butylene, isobutylene and mixtures thereof.
Propane containing too much propene (also called propylene) is not suited for most vehicle fuels. HD-5 is a specification which establishes a maximum concentration of 5% propene in propane. Propane and other LP gas specifications are established in ASTM D-1835. All propane fuels include an odorant, almost always ethanethiol, so that people can easily smell the gas in case of a leak. Propane as HD-5 was originally intended for use as vehicle fuel. HD-5 is currently being used in all propane applications.
Propane was first identified as a volatile component in gasoline by Walter O. Snelling of the U.S. Bureau of Mines in 1910. The volatility of these lighter hydrocarbons caused them to be known as "wild" because of the high vapor
Swainsonine is an indolizine alkaloid. It is a potent inhibitor of Golgi alpha-mannosidase II, an immunomodulator, and a potential chemotherapy drug. As a toxin in locoweed (likely its primary toxin) it also is a significant cause of economic losses in livestock industries, particularly in North America.
Swainsonine inhibits glycoside hydrolases, specifically N-linked glycosylation. Disruption of Golgi alpha-mannosidase II with swainsonine induces hybrid-type glycans. These glycans have a Man5GlcNAc2 core with processing on the 3-arm that resembles so-called complex-type glycans.
The pharmacological properties of this product have not been fully investigated.
Swainsonine is a natural product that has been isolated from numerous species of flowering plants and some fungi (see Locoweed). It was first isolated from Swainsona in Australia.
Swainsonine is extracted commercially from several species of plants and fungi, including the soil fungus Metarhizium anisopliae. It also can be produced from total synthesis.
The biosynthesis of swainsonine has been investigated in the fungus Rhizoctonia leguminicola, and it initially involves the conversion of lysine into pipecolic acid. The
Terbium(III) oxide, also known as terbium sesquioxide, is a sesquioxide of the rare earth metal terbium, having chemical formula Tb2O3. It is a p-type semiconductor when doped with calcium, and may be prepared by the reduction of Tb4O7 in hydrogen at 1300 °C for 24 hours.
It is a p-type semiconductor.
It is a basic oxide and easily dissolved to dilute acids, and then almost colourless terbium salt is formed.
The crystal structure is cubic and the lattice constant is a = 1057 pm.
Trichlorofluoromethane, also called freon-11, CFC-11, or R-11, is a chlorofluorocarbon. It is a colorless, nearly odorless liquid that boils at about room temperature.
It was the first widely used refrigerant. Because of its high boiling point (compared to most refrigerants), it can be used in systems with a low operating pressure, making the mechanical design of such systems less demanding than that of higher-pressure refrigerants R-12 or R-22.
R-11 is assigned an ozone depletion potential of 1.0. U.S. production was ended in January 1, 1996.
Trichlorofluoromethane is used as a reference compound for fluorine-19 NMR studies.
Years ago, prior to the knowledge of the ozone depletion potential of chlorine in refrigerants and other possible harmful effects on the environment, Trichlorofluoromethane was sometimes used as a cleaning/rinsing agent for low pressure systems, often dumping the used and "dirty" liquid (if cool enough) into waterways.
The following products use Trichloroflouromethane:
Col Spray : Surface Coolant MFD. BY Cramer Products, Inc. GARDNER KANSAS U. S. A. 66030 STOCK NO. 033529
Trinitrotoluene ( /ˌtraɪnaɪtrɵˈtɒljʉ.iːn/; TNT), or more specifically, 2,4,6-trinitrotoluene, is a chemical compound with the formula C6H2(NO2)3CH3. This yellow-colored solid is sometimes used as a reagent in chemical synthesis, but it is best known as a useful explosive material with convenient handling properties. The explosive yield of TNT is considered to be the standard measure of strength of bombs and other explosives. In chemistry, TNT is used to generate charge transfer salts.
In industry, TNT is produced in a three-step process. First, toluene is nitrated with a mixture of sulfuric and nitric acid to produce mono-nitrotoluene or MNT. The MNT is separated and then renitrated to dinitrotoluene or DNT. In the final step, the DNT is nitrated to trinitrotoluene or TNT using an anhydrous mixture of nitric acid and oleum. Nitric acid is consumed by the manufacturing process, but the diluted sulfuric acid can be reconcentrated and reused. Subsequent to nitration, TNT is stabilized by a process called sulphitation, where the crude TNT is treated with aqueous sodium sulfite solution in order to remove less stable isomers of TNT and other undesired reaction products. The rinse water
8-Hydroxyquinoline is an organic compound with the formula C9H7NO. It is a derivative of the heterocycle quinoline by placement of an OH group on carbon number 8. This light yellow compound is widely used commercially, although under a variety of names.
It is usually prepared from quinoline-8-sulfonic acid and from a Skraup synthesis from 2-aminophenol.
8-Hydroxyquinoline is a monoprotic bidentate chelating agent. Related ligands are the Schiff bases derived from salicylaldehyde, such as salicylaldoxime and salen. In neutral solution, the hydroxyl is in the protonated form (pKa=9.89) and the nitrogen is not protonated (pKa=5.13). However, an excited-state zwitterionic isomer exists in which H is transferred from the oxygen (giving an oxygen anion) to the nitrogen (giving a protonated nitrogen cation).
The complexes as well as the heterocycle itself exhibit antiseptic, disinfectant, and pesticide properties, functioning as a transcription inhibitor. Its solution in alcohol is used as liquid bandages. It once was of interest as an anti-cancer drug.
The reaction of 8-hydroxyquinoline with aluminium(III) results in Alq3, a common component of organic light-emitting diodes (OLED's).
Cyclic adenosine monophosphate (cAMP, cyclic AMP or 3'-5'-cyclic adenosine monophosphate) is a second messenger important in many biological processes. cAMP is derived from adenosine triphosphate (ATP) and used for intracellular signal transduction in many different organisms, conveying the cAMP-dependent pathway.
Earl Sutherland of Case Western Reserve University won a Nobel Prize in Physiology or Medicine in 1971 "for his discoveries concerning the mechanisms of the action of hormones," especially epinephrine, via second messengers (such as cyclic adenosine monophosphate, cyclic AMP).
cAMP is synthesised from ATP by adenylyl cyclase located on the inner side of the plasma membrane. Adenylyl cyclase is activated by a range of signaling molecules through the activation of adenylyl cyclase stimulatory G (Gs)-protein-coupled receptors and inhibited by agonists of adenylyl cyclase inhibitory G (Gi)-protein-coupled receptors. Liver adenylyl cyclase responds more strongly to glucagon, and muscle adenylyl cyclase responds more strongly to adrenaline.
cAMP decomposition into AMP is catalyzed by the enzyme phosphodiesterase.
cAMP is a second messenger, used for intracellular signal
Ethyl butyrate, also known as ethyl butanoate, or butyric ether, is an ester with the chemical formula CH3CH2CH2COOCH2CH3. It is soluble in propylene glycol, paraffin oil, and kerosene. It has a fruity odor, similar to pineapple.
It is commonly used as artificial flavoring such as pineapple flavoring in alcoholic beverages (e.g. martinis, daiquiris etc.), as a solvent in perfumery products, and as a plasticizer for cellulose. In addition, ethyl butyrate is often also added to orange juice, as most associate its odor with that of fresh orange juice.
Ethyl butyrate is one of the most common chemicals used in flavors and fragrances. It can be used in a variety of flavors: orange (most common), cherry, pineapple, mango, guava, bubblegum, peach, apricot, fig, and plum. In industrial use, it is also one of the cheapest chemicals, which only adds to its popularity.
It can be synthesized by reacting ethanol and butyric acid. This is a condensation reaction, meaning water is produced in the reaction as a byproduct.
trans-Glutaconic acid is an organic compound with formula HO2CCH=CHCH2CO2H. This dicarboxylic acid exists as a colorless solid and is related to the saturated chemical glutaric acid, HO2CC(CH2)3CO2H. Esters and salts of glutaconic acid are called glutaconates.
The geometric isomer, cis-glutaconic acid, has a noticeably lower melting point (130–132 °C). It can be prepared by bromination of levulinic acid followed by treatment of the dibromoketone with potassium carbonate.
Glutaconic anhydride, which forms by dehydration the diacid, exists mainly as the dicarbonyl tautomer in solution. It is a colorless solid melting at 77–82 °C. Either the cis or trans diacid can be used to make it: the trans form isomerizes under the reaction conditions.
Glutaric, 3-hydroxglutaric, and glutaconic acids are structurally related metabolites. In Glutaric aciduria type 1, glutaconic acid accumulates, resulting in brain damage.
Ifenprodil is a selective inhibitor of the NMDA receptor. Its effect is specific to receptors composed of the NR1 (glutamate-binding NMDA receptor subunit 1; GluN1) and NR2B (GluN2B) subunits.
NMDA receptors are multimeric ionotropic glutamate receptors composed of four subunits. NR1 is obligate for functional expression. Other subunits include NR2A, NR2B, and the more recently discovered NR3 subunits. Ifenprodil selectively blocks NMDA receptors containing the NR2B subunit.
Nordihydroguaiaretic acid (NDGA) is a potent antioxidant compound found in the long-lived creosote bush. It is believed that NDGA reduces cell damage by free radicals, so under the free-radical theory of aging, could be responsible for the bush's long life.
A 1986 study involved feeding female mosquitos NDGA to test the effect on their average life span. While the usual mosquito life span was 29 days, the NDGA-fed mosquitos lived an average of 45 days—an increase of 50 percent.
A 2008 study reported that nordihydroguaiaretic acid lengthened the lifespan of male mice, but not of female mice.
The plant has been used to treat a variety of illnesses including infertility, rheumatism, arthritis, diabetes, gallbladder and kidney stones, pain and inflammation but its use is controversial. It was widely used during the 1950s as a food preservative and to preserve natural fibers but was later banned after reports of toxicity during the early 1960s. Recently, it has been used as a nutritional supplement, however renal and hepatotoxicity are reported for chronic use of creosote bush and NDGA.
Methoxamine is an α1-adrenergic receptor agonist, similar in structure to phenylephrine and 2,5-DMA. It was Developed by Burroughs-Wellcome in the 1940s. The drug induces vasoconstriction of skin and splanchnic blood vessels, thereby increasing peripheral vascular resistance and raising mean arterial blood pressure. Because of its hypertensive effects, it may evoke a compensatory reflex bradycardia via the baroreceptors.
Tricaine mesylate (Tricaine methanesulfonate, TMS, MS-222), is white powder used for anesthesia, sedation, or euthanasia of fishes. TMS is the only anesthetic licensed in the United States for fin fish that is intended for human consumption. The drug can have selective toxicity for poikilotherms due to their lower rate of metabolism in the liver.
TMS is a muscle relaxant that operates by preventing action potentials. By blocking action potentials, no signals can be exchanged between the brain and the extremities. There will be no sensory input or muscle contractions which would have been caused by action potential, which includes most muscles.
The optimum concentration used is 50-75 ppm (parts per million). However, the optimum may vary with the size and species of the fish, and other variables.
It is easily soluble in water (both fresh and salt) but it drastically decreases the pH of water, increasing the acidity, which may be toxic for fish. Baking soda or sodium bicarbonate is used to buffer the solution to a pH range of 6.5-7.5. Usually an equal amount of buffer is added to attain a neutral pH . In salt/marine/sea water, the buffer use may not be necessary because sea water
Uridine diphosphate glucose (uracil-diphosphate glucose, UDP-glucose) is a nucleotide sugar. It is involved in glycosyltransferase reactions in metabolism.
It is used in nucleotide sugars metabolism as an activated form of glucose as a substrate for enzymes called glucosyltransferases.
It is a precursor of glycogen and can be converted into UDP-galactose and UDP-glucuronic acid, which can then be used as substrates by the enzymes that make polysaccharides containing galactose and glucuronic acid.
UDP-glucose can also be used as a precursor of sucrose lipopolysaccharides, and glycosphingolipids.
UDP-glucose consists of the pyrophosphate group, the pentose sugar ribose, glucose, and the nucleobase uracil.
para-Cresidine is an intermediate that is used to create dyes and pigments. It is a light yellow to light brown solid with the chemical formula C8H11ON or CH3OC6H3(CH3)NH2. It appears as white crystals. Its carcinogen category is 2, and upon heating it produces toxic fumes including nitrogen oxides. It reacts with strong oxidants and some forms of plastic, rubber, and coatings. para-Cresidine is possibly carcinogenic to humans. It boils at 235 °C, melts at 51.5 °C, and is not very soluble in water.
Chloromethane, also called methyl chloride, R-40 or HCC 40, is a chemical compound of the group of organic compounds called haloalkanes. It was once widely used as a refrigerant. It is a colorless extremely flammable gas with a mildly sweet odor, which is, however, detected at possibly toxic levels. Due to concerns about its toxicity, it is no longer present in consumer products. Chloromethane was first synthesized by the French chemists Jean-Baptiste Dumas and Eugene Peligot in 1835 by boiling a mixture of methanol, sulfuric acid, and sodium chloride. This method is similar to that used today.
Chloromethane is the most abundant organohalogen, anthropogenic or natural, in the atmosphere.
Laboratory cultures of marine phytoplankton (Phaeodactylum tricornutum, Phaeocystis sp., Thalassiosira weissflogii, Chaetoceros calcitrans, Isochrysis sp., Porphyridium sp., Synechococcus sp., Tetraselmis sp., Prorocentrum sp., and Emiliana huxleyi) produce CH3Cl, but in relatively insignificant amounts. An extensive study of 30 species of polar macroalgae revealed the release of significant amounts of CH3Cl in only Gigartina skottsbergii and Gymnogongrus antarcticus.
The salt marsh plant Batis
Hydrogen cyanide (with the alternate archaic name of prussic acid) is an inorganic compound with chemical formula HCN. It is a colorless, extremely poisonous liquid that boils slightly above room temperature at 26 °C (79 °F). Hydrogen cyanide is a linear molecule, with a triple bond between carbon and nitrogen. A minor tautomer of HCN is HNC, hydrogen isocyanide.
Hydrogen cyanide is weakly acidic with a pKa of 9.2. It partly ionizes in water solution to give the cyanide anion, CN. A solution of hydrogen cyanide in water is called hydrocyanic acid. The salts of hydrogen cyanide are known as cyanides.
HCN has a faint, bitter, almond-like odor that only some people are able to detect owing to a genetic trait. The volatile compound has been used as inhalation rodenticide and human poison. Cyanide ions interfere with iron-containing respiratory enzymes.
HCN is produced on an industrial scale and is a highly valuable precursor to many chemical compounds ranging from polymers to pharmaceuticals.
Hydrogen cyanide was first isolated from a blue pigment (Prussian blue) which had been known from 1704 but whose structure was unknown. It is now known to be a coordination polymer with a complex
Methionine ( /mɛˈθaɪ.ɵniːn/ or /mɛˈθaɪ.ɵnɪn/; abbreviated as Met or M) is an α-amino acid with the chemical formula HO2CCH(NH2)CH2CH2SCH3. This essential amino acid is classified as nonpolar. This amino-acid is coded by the codon AUG, also known as the initiation codon, since it indicates mRNA's coding region where translation into protein begins.
Together with cysteine, methionine is one of two sulfur-containing proteinogenic amino acids. Its derivative S-adenosyl methionine (SAM) serves as a methyl donor. Methionine is an intermediate in the biosynthesis of cysteine, carnitine, taurine, lecithin, phosphatidylcholine, and other phospholipids. Improper conversion of methionine can lead to atherosclerosis.
This amino acid is also used by plants for synthesis of ethylene. The process is known as the Yang Cycle or the methionine cycle.
Methionine is one of only two amino acids encoded by a single codon (AUG) in the standard genetic code (tryptophan, encoded by UGG, is the other). The codon AUG is also the "Start" message for a ribosome that signals the initiation of protein translation from mRNA. As a consequence, methionine is incorporated into the N-terminal position of all proteins
Tetrahydrocannabinol ( /ˌtɛtrəˌhaɪdrɵkəˈnæbɨnɒl/ tet-rə-HY-drə-kə-NAB-i-nol; THC), also known as delta-9-tetrahydrocannabinol (Δ-THC), is the principal psychoactive constituent of the cannabis plant. First isolated in 1964, in its pure form, it is a glassy solid when cold, and becomes viscous and sticky if warmed. Synthetically prepared THC, officially referred to by its INN, dronabinol, is available by prescription in the U.S. and Canada under the brand name Marinol. An aromatic terpenoid, THC has a very low solubility in water, but good solubility in most organic solvents, specifically lipids and alcohols.
Like most pharmacologically-active secondary metabolites of plants, THC in cannabis is assumed to be involved in self-defense, perhaps against herbivores but as of now it is still unknown. THC also possesses high UV-B (280-315 nm) absorption properties, which, it has been speculated, could protect the plant from harmful UV radiation exposure.
The pharmacological actions of THC result from its partial agonist activity at the cannabinoid receptor CB1, located mainly in the central nervous system, and the CB2 receptor, mainly expressed in cells of the immune system. The
Pentafluoroethane is a refrigerant that has zero ozone depletion potential.It has the formula CF3CHF2. Although it has zero ozone depletion potential, it has high global warming potential, reported by the United States Environmental Protection Agency (EPA) as 3450 times that of carbon dioxide.
Pentafluoroethane in an zeotropic mixture with difluoromethane is known as R-410A, a common replacement for various chlorofluorocarbons (commonly known as Freon) in new refrigerant systems. Pentafluoroethane is also used as a fire suppression agent in fire suppression systems.
HFC-125 (ECARO-25 / FE-25 / NAF S 125) can be used in clean agent fire suppression systems also referred to as Gaseous fire suppression Agent. It is generally used in situations where water from a fire sprinkler would damage expensive equipment or where water-based fire protection is impractical, such as museums, banks, clean rooms and hospitals . HFC-125 does not deplete ozone (ODP 0) The HFC-125 clean agent is stored in a pressurized container and introduced into the hazard as a gas. The agent is odorless, colorless, electrically non-conductive, non-corrosive, and leaves no residue. It is used in occupied enclosed
Acetyl iodide is an organoiodine compound wth the formula CH3C(O)I. It is a colourless liquid. It is formally derived from acetic acid. Although far rarer in the laboratory than the related acetyl bromide and acetyl chloride, acetyl iodide is produced, transiently at least, on a far larger scale than any other acid halide. Specifically, it is generated by the carbonylation of methyl iodide in the Cativa and Monsanto processes that are the main industrial route to acetic acid. It is also an intermediate in the production of acetic anhydride from methyl acetate.
Upon treatment with carboxylic acids, acetyl iodide does not exhibit reactions typical of acyl halides, such as acetyl chloride. Instead, acetyl iodide undergoes iodide/hydroxide exchange with most carboxylic acids:
Cyclohexene is a hydrocarbon with the formula C6H10. This cycloalkene is a colorless liquid with a sharp smell. It is an intermediate in various industrial processes. Cyclohexene is not very stable upon long term storage with exposure to light and air because it forms peroxides.
Cyclohexene is produced by the partial hydrogenation of benzene, a process developed by Asahi Chemical Company. It is converted to cyclohexanol, which is dehydrogenated to give cyclohexanone, a precursor to caprolactam. Cyclohexene is also a precursor to adipic acid, maleic acid, dicyclohexyladipate, and cyclohexeneoxide. Furthermore, it is used as a solvent.
A common experiment for beginning organic chemistry students is the acid catalyzed dehydration of cyclohexanol with distillative removal of the resulting cyclohexene from the reaction mixture:
Dibenzofuran, is a heterocyclic organic compound with the chemical structure shown at right. It is an aromatic compound that has two benzene rings fused to one furan ring in the middle. All of the numbered carbon atoms have a hydrogen atom bonded to each of them (not shown in the image). Dibenzofuran is an aromatic ether having the chemical formula C12H8O.
Dibenzofurans can also inaccurately refer to polychlorinated dibenzofurans (PCDFs), a family of organic compounds with one or several of the hydrogens in the dibenzofuran structure replaced by chlorines. For example, 2,3,7,8-tetrachlorodibenzofuran (TCDF) has chlorine atoms substituted for each of the hydrogens on the number 2, 3, 7, and 8 carbons (see structure below). Polychlorinated dibenzofurans are much more toxic chemicals than the parent compounds with properties and chemical structures similar to polychlorinated dibenzodioxins. These groups together are often inaccurately called dioxins.
Probable places of origin It is a white crystal-like solid created from production of coal tar. It is used as an insecticide, in the production of PVC, industrial bleaching and incineration.
Production and Producers: Dibenzofuran is
Diiodomethane or methylene iodide, commonly abbreviated "MI", is an organoiodine compound. Diiodomethane is a colorless liquid, however, it decomposes upon exposure to light liberating iodine, which colours samples brownish. It is slightly soluble in water, but soluble in organic solvents. It has a relatively high refractive index of 1.741, and a surface tension of 0.0508 N·m.
Because of its high density, diiodomethane is used in the determination of the density of mineral and other solid samples. It is also used as a contact liquid for refractometers; e.g. when testing the authenticity of diamonds, with which the compound shares a similar density. Diiodomethane is a reagent in the Simmons-Smith reaction, serving as a source of methylene CH2.
Although commercially available, it can be prepared by reducing iodoform with sodium arsenite:
Diiodomethane can also be prepared from dichloromethane by the action of sodium iodide in acetone in the Finkelstein reaction:
Alkyl iodides are alkylating agents and contact should be avoided.
Methylisothiazolinone or MIT, sometimes erroneously called methylisothiazoline, is a powerful biocide and preservative within the group of isothiazolinones, used in personal care products.
Methylisothiazolinone and other isothiazolinone-derived biocides are utilized for controlling microbial growth in water-containing solutions. Two of the most widely used isothiazolinone biocides are 5-chloro-2-methyl-4-isothiazolin-3-one (chloromethylisothiazolinone or CMIT) and 2-methyl-4-isothiazolin-3-one (methylisothiazolinone or MIT), which are the active ingredients in a 3:1 mixture (CMIT:MIT) sold commercially as Kathon™. Kathon™ is supplied to manufacturers as a concentrated stock solution containing from 10-15% of CMIT/MIT. For applications the recommended use level is from 6 ppm to 75 ppm active isothiazolones. Biocidal applications range from industrial water storage tanks to cooling units, in processes as varied as mining, paper manufacturing, metalworking fluids and energy production. In addition, one isothiazolinone, Sea-Nine 211 (4,5-dichloro-2-n-octyl-4-isothiazolino-3-one, DCOI), has quickly replaced tributyltin as the antifouling agent of choice in ship hull paint. A recent
NIM811 is a mitochondrial permeability transition inhibitor. Also known as N-methyl-4-isoleucine cyclosporin, it is a four-substituted cyclosporine that does not bind to cyclophilin A and therefore lacks immunosuppressive activity. Rather, NIM811 binds and inhibits cyclophilin.
1-Propanol is a primary alcohol with the formula CH3CH2CH2OH. This colorless liquid is also known as propan-1-ol, 1-propyl alcohol, n-propyl alcohol, n-propanol, or simply propanol. It is an isomer of isopropanol (2-propanol). It is used as a solvent in the pharmaceutical industry, and for resins and cellulose esters. It is formed naturally in small amounts during many fermentation processes.
1-Propanol shows the normal reactions of a primary alcohol. Thus it can be converted to alkyl halides; for example red phosphorus and iodine produce n-propyl iodide in 80% yield, while PCl3 with catalytic ZnCl2 gives 1-chloropropane. Reaction with acetic acid in the presence of an H2SO4 catalyst under Fischer esterification conditions gives propyl acetate, while refluxing propanol overnight with formic acid alone can produce propyl formate in 65% yield. Oxidation of 1-propanol with Na2Cr2O7 and H2SO4 gives only a 36% yield of propionaldehyde, and therefore for this type of reaction higher yielding methods using PCC or the Swern oxidation are recommended. Oxidation with chromic acid yields propionic acid.
1-Propanol is manufactured by catalytic hydrogenation of propionaldehyde. The
Tryptophan tryptophylquinone(TTQ) is an enzyme cofactor, generated by post-translationational modification of amino acids within the protein. Methylamine dehydrogenase (MADH), an amine dehydrogenase, requires TTQ for its catalytic function.
Aziridines are organic compounds containing the aziridine functional group, a three-membered heterocycle with one amine group and two methylene groups. The parent compound is aziridine (or ethylene imine), with molecular formula C2H5N.
The bond angles in aziridine are approximately 60°, considerably less than the normal hydrocarbon bond angle of 109.5°, which results in angle strain as in the comparable cyclopropane and ethylene oxide molecules. A banana bond model explains bonding in such compounds. Aziridine is less basic than acyclic aliphatic amines, with a pKa of 7.9 for the conjugate acid, due to increased s character of the nitrogen free electron pair. Angle strain in aziridine also increases the barrier to nitrogen inversion. This barrier height permits the isolation of separate invertomers, for example the cis and trans invertomers of N-chloro-2-methylaziridine.
There are several syntheses of aziridines.
An amine functional group displaces the adjacent halide in an intramolecular nucleophilic substitution reaction to generate an aziridine. Amino alcohols have the same reactivity, but the hydroxy group must first be converted into a good leaving group. The cyclization of an
Bromobimane (or monobromobimane) is a heterocyclic compound and bimane dye that is used as a reagent in biochemistry. It alkylates thiol groups, displacing the bromine and adding the fluorescent tag (λemission = 478 nm) to the thiol. Its alkylating properties are comparable to iodoacetamide.
Cacodylic acid is the chemical compound with the formula (CH3)2AsO2H. Derivatives of cacodylic acid, cacodylates, were frequently used as herbicides. For example, "Agent Blue," one of the chemicals used during the Vietnam War, is a mixture of cacodylic acid and sodium cacodylate. Sodium cacodylate is frequently used as a buffering agent in the preparation and fixation of biological samples for electron microscopy.
Significant early research into cacodyls was done by Robert Bunsen at the University of Marburg. Bunsen said of the compounds, "the smell of this body produces instantaneous tingling of the hands and feet, and even giddiness and insensibility...It is remarkable that when one is exposed to the smell of these compounds the tongue becomes covered with a black coating, even when no further evil effects are noticeable". His work in this field led to an increased understanding of the methyl radical.
Cacodyloxide, ((CH3)2As)2O, is often considered the first organometallic compound to be prepared synthetically.
In the 18th century it was known that combining As2O3 and four equivalents of potassium acetate (CH3CO2K) gives a product called "Cadet's fuming liquid" which contains
Daidzein structurally belongs to the group of isoflavones. Daidzein and other isoflavone compounds, such as genistein, are present in a number of plants and herbs like the Thai Kwao Krua or Pueraria mirifica, Kudzu or Pueraria lobata, and in food sources such as soybeans and soy products like tofu and textured vegetable protein. Soy isoflavones are a group of compounds found in and isolated from the soybean. Of note, total isoflavones in soy beans are—in general—37 percent daidzein, 57 percent genistein and 6 percent glycitein, according to USDA data. Soy germ contains 41.7 percent daidzein. Besides functioning as antioxidants, isoflavones have been shown to interact with animal and human estrogen receptors, and are therefore referred to as phytoestrogens. Soy isoflavones also produce non-hormonal effects.
Daidzein can be converted to its end metabolite S-equol in some humans based on the presence of certain intestinal bacteria. Based on several decades of research, S-equol has potential for significant health benefits.
Daidzein is not legally classified as a drug in the United States. It has not been tested in clinical trials to make sure that it is both safe and effective for
Iodoform is the organoiodine compound with the formula CHI3. A pale yellow, crystalline, volatile substance, it has a penetrating odor (in older chemistry texts, the smell is sometimes referred to as the smell of hospitals) and, analogous to chloroform, sweetish taste. It is occasionally used as a disinfectant. It is also known as tri-iodomethane, and sometimes also referred to as carbon triiodide (which is not strictly correct, as this compound also contains hydrogen) or methyl triiodide (which is somewhat ambiguous as that name could also refer to the methylated triiodide ion, CH3I3).
Iodoform was first prepared by Georges Serrulas in 1822; and at much the same time independently by John Thomas Cooper. It is synthesized in the haloform reaction by the reaction of iodine and sodium hydroxide with any one of these four kinds of organic compounds: (i) a methyl ketone: CH3COR, acetaldehyde (CH3CHO), ethanol (CH3CH2OH), and certain secondary alcohols (CH3CHROH, where R is an alkyl or aryl group).
The reaction of iodine and base with methyl ketones is so reliable, that the "iodoform test" (the appearance of a yellow precipitate) is used to probe the presence of a methyl ketone. This is
Magnesium citrate, a magnesium preparation in salt form with citric acid, is a chemical agent used medicinally as a saline laxative and to completely empty the bowel prior to a major surgery or colonoscopy. It is available without a prescription, both as a generic or under the brand name Citromag or Citroma. It is also used as a magnesium supplement in pills. The magnesium content of magnesium citrate corresponds to about 11% by mass.
Magnesium citrate works by attracting water through the tissues by a process known as osmosis. Once in the intestine, it can attract enough water into the intestine to induce defecation. The additional water helps to create more feces, which naturally stimulates bowel motility. This means it can also be used to treat rectal and colon problems. Magnesium citrate functions best on an empty stomach, and should always be followed with a full (eight ounce) glass of water or juice to help the magnesium citrate absorb properly and help prevent any complications. Magnesium citrate is generally not a harmful substance, but care should be taken by consulting a health-care professional if any adverse health problems are suspected or experienced.
DAPI or 4',6-diamidino-2-phenylindole is a fluorescent stain that binds strongly to A-T rich regions in DNA. It is used extensively in fluorescence microscopy. DAPI can pass through an intact cell membrane therefore it can be used to stain both live and fixed cells, though it passes through the membrane less efficiently in live cells and therefore the effectiveness of the stain is lower.
DAPI was first synthesised in 1971 in the laboratory of Otto Dann as part of a search for drugs to treat trypanosomiasis although it was unsuccessful as a drug. Further investigation indicated it bound strongly to DNA and became more fluorescent when it did so. This led to its use in identifying mitochondrial DNA in ultracentrifugation in 1975, the first recorded use of DAPI as a fluorescent DNA stain.
Strong fluorescence when bound to DNA led to the rapid adoption of DAPI for fluorescent staining of DNA for fluorescence microscopy. Its use for detecting DNA in plant, metazoa and bacteria cells and virus particles was demonstrated in the late 1970s, and quantitative staining of DNA inside cells was demonstrated in 1977. Use of DAPI as a DNA stain for flow cytometry was also demonstrated around this
Dopamine (abbreviated as DA), a simple organic chemical in the catecholamine family, is a monoamine neurotransmitter which plays a number of important physiological roles in the bodies of animals. In addition to being a catecholamine and a monoamine, dopamine may be classified as a substituted phenethylamine. Its name derives from its chemical structure, which consists of an amine group (NH2) linked to a catechol structure called dihydroxyphenethylamine, the decarboxylated form of dihydroxyphenylalanine (acronym DOPA). In the brain, dopamine functions as a neurotransmitter—a chemical released by nerve cells to send signals to other nerve cells. The human brain uses five known types of dopamine receptors, labeled D1, D2, D3, D4, and D5. Dopamine is produced in several areas of the brain, including the substantia nigra and the ventral tegmental area.
Dopamine plays a major role in the brain system that is responsible for reward-driven learning. Every type of reward that has been studied increases the level of dopamine transmission in the brain, and a variety of highly addictive drugs, including stimulants such as cocaine and methamphetamine, act directly on the dopamine system. There
"Niacin" redirects here. For the neo-fusion band, see Niacin (band).
Niacin (also known as vitamin B3, nicotinic acid and vitamin PP) is an organic compound with the formula C6H5NO2 and, depending on the definition used, one of the forty to eighty essential human nutrients.
Niacin is one of five vitamins (when lacking in human diet) associated with a pandemic deficiency disease: niacin deficiency (pellagra), vitamin C deficiency (scurvy), thiamin deficiency (beriberi), vitamin D deficiency (rickets), vitamin A deficiency (night blindness and other symptoms). Niacin has been used for over 50 years to increase levels of HDL in the blood and has been found to modestly decrease the risk of cardiovascular events in a number of controlled human trials.
This colorless, water-soluble solid is a derivative of pyridine, with a carboxyl group (COOH) at the 3-position. Other forms of vitamin B3 include the corresponding amide, nicotinamide ("niacinamide"), where the carboxyl group has been replaced by a carboxamide group (CONH2), as well as more complex amides and a variety of esters.
Niacin cannot be directly converted to nicotinamide, but both compounds could be converted to NAD and NADP in
Phytanic acid (or 3,7,11,15-tetramethyl hexadecanoic acid) is a branched chain fatty acid that humans can obtain through the consumption of dairy products, ruminant animal fats, and certain fish. Western diets are estimated to provide 50-100 mg of phytanic acid per day. In a study conducted in Oxford, individuals who consumed meat had, on average, a 6.7-fold higher geometric mean plasma phytanic acid concentration than did vegans.
Unlike most fatty acids, phytanic acid cannot be metabolized by β-oxidation. Instead, it undergoes α-oxidation in the peroxisome, where it is converted into pristanic acid by the removal of one carbon. Pristanic acid can undergo several rounds of β-oxidation in the peroxisome to form medium chain fatty acids that can be converted to carbon dioxide and water in mitochondria.
Individuals with adult Refsum disease, an autosomal recessive neurological disorder caused by mutations in the PHYH gene, have impaired α-oxidation activity and accumulate large stores of phytanic acid in their blood and tissues. This frequently leads to peripheral polyneuropathy, cerebellar ataxia, retinitis pigmentosa, anosmia, and hearing loss.
In ruminant animals, the gut
Anatoxin-a, also known as Very Fast Death Factor, is a secondary, bicyclic amine alkaloid and cyanotoxin with acute neurotoxicity. The toxin is produced by at least four different genera of cyanobacteria and has been reported in North America, Europe, Africa, Asia, and New Zealand. The toxin is much less likely to be identified in the southern hemisphere. Symptoms of anatoxin exposure are loss of coordination, muscular fasciculations, convulsions and death by respiratory paralysis. Its mode of action is through the nicotinic acetylcholine receptor where it acts as an analogue of acetylcholine. The molecule is not degraded by cholinesterase, thus causing permanent stimulation of muscle cells leading to paralysis. Information on carcinogenicity is not currently available.
The arsenate ion is AsO4. An arsenate (compound) is any compound that contains this ion. Arsenates are salts or esters of arsenic acid.
The arsenic atom in arsenate has a valency of 5 and is also known as pentavalent arsenic or As[V].
Arsenate resembles phosphate in many respects, since arsenic and phosphorus occur in the same group (column) of the periodic table.
Arsenates are moderate oxidizers, with an electrode potential of +0.56 for reduction to arsenites.
Arsenates occur naturally in a variety of minerals. Those minerals may contain hydrated or anhydrous arsenates. Unlike phosphates, arsenates are not lost from a mineral during weathering. Examples of arsenate-containing minerals include adamite, alarsite, annabergite, erythrite and legrandite.
Arsenate can replace inorganic phosphate in the step of glycolysis that produces 1,3-bisphosphoglycerate from glyceraldehyde 3-phosphate. This yields 1-arseno-3-phosphoglycerate instead, which is unstable and quickly hydrolyzes, forming the next intermediate in the pathway, 3-phosphoglycerate. Therefore glycolysis proceeds, but the ATP molecule that would be generated from 1,3-bisphosphoglycerate is lost - arsenate is an uncoupler of
Barium peroxide is the chemical compound with the formula BaO2. This grey-white solid is one of the most common inorganic peroxides. Barium peroxide is an oxidizing agent, which is used for bleaching. It is used in fireworks as an oxidizer, which also gives a vivid green colour, as do all barium compounds.
Barium peroxide is a peroxide, containing O2−
2 subunits wherein the oxygen atoms bond to each other as well as to the barium. The solid adopts the same structure as calcium carbide, CaC2.
Barium peroxide arises by the reversible absorption of O2 by barium oxide. The oxygen is released above 500 °C.
This reaction is the basis for the now-obsolete Brin process for separating oxygen from the atmosphere. Other oxides, e.g. Na2O, behave similarly.
Hydrogen peroxide can also be prepared via the related reaction:
The insoluble barium sulfate is filtered from the mixture.
Benzilic acid is a white crystalline aromatic acid soluble in many primary alcohols. It can be prepared by heating mixture of benzil, alcohol and potassium hydroxide. The other preparation way is through benzaldehyde, which dimerizates to benzil and it is further transformed by benzilic acid rearrangement to benzilic acid. This reaction was also the first example of benzilic acid rearrangement performed by Liebig in 1838.
Benzilic acid is used in organic synthesis, as a base point for preparation of glycollate pharmaceuticals and some hallucinogenic drugs.
Hypoxanthine is a naturally occurring purine derivative. It is occasionally found as a constituent of nucleic acids, where it is present in the anticodon of tRNA in the form of its nucleoside inosine. It has a tautomer known as 6-hydroxypurine. Hypoxanthine is a necessary additive in certain cell, bacteria, and parasite cultures as a substrate and nitrogen source. For example, it is commonly a required reagent in malaria parasite cultures, since Plasmodium falciparum requires a source of hypoxanthine for nucleic acid synthesis and energy metabolism.
In August 2011, a report, based on NASA studies with meteorites found on Earth, was published suggesting hypoxanthine and related organic molecules, including the DNA and RNA components adenine and guanine, may have been formed extraterrestrially in outer space.
It is one of the products of the action of xanthine oxidase on xanthine. However, more frequently in purine degradation, hypoxanthine is formed from reduction of xanthine by xanthine oxidoreductase.
Hypoxanthine-guanine phosphoribosyltransferase converts hypoxanthine into IMP in nucleotide salvage.
Hypoxanthine is also a spontaneous deamination product of adenine. Because of its
3,3′-Diindolylmethane or DIM is a compound derived from the digestion of indole-3-carbinol, found in cruciferous vegetables such as broccoli, Brussels sprouts, cabbage and kale. The reputation of Brassica vegetables as healthy foods rests in part on the activities of diindolylmethane.
DIM has the biological properties listed in the chart below. Because of its various potent anticancer properties, the National Cancer Institute of the United States has begun clinical trials of DIM as a therapeutic for numerous forms of cancer.
At the present time, DIM is used to treat recurrent respiratory papillomatosis (RRP), a rare respiratory disease with tumors in the upper respiratory tracts caused by the human papilloma virus. In a double-blind, randomized, placebo-controlled study, DIM had a small but significant effect on cytology regarding cervical dysplasia, a precancerous condition also caused by the human papilloma virus. Similarly, it has been studied and shown promising results as a immunostimulant against HPV.
α-Carotene is a form of carotene with a β-ring at one end and an ε-ring at the other. It is the second most common form of carotene.
In US adults and Chinese adults the mean concentration of serum α-carotene was 4.71 µg/dL, including 4.22 µg/dL among men and 5.31 µg/dL among women (to convert to micromoles per liter, multiply by 0.01863).
Dietary intake affects blood levels of α-carotene which was associated with significantly lower risk of death, in one study.
The following vegetables are rich in alpha-carotene :
Ammelide (6-Amino-2,4-Dihydroxy-1,3,5-Triazine) is a triazine and the hydrolysis product of ammeline.
Ammelide can be obtained by heating dicyandiamide with aqueous ammonia at 160−170 °C. It can also be synthezised by heating melam with concentrated sulfuric acid for a short time at 190 °C.
Ammelide forms salts with both acids (hydrochloric acid, nitric acid, sulfuric acid)and bases (sodium hydroxide, ammonium, calcium hydroxide).
Ammelide decomposes at 170 °C with water to form carbon dioxide and ammonia. It can be converted into cyanuric acid by oxidizing agents (e.g. potassium permanganate) or by boiling with acids or alkalies.
Dithiothreitol (DTT) is the common name for a small-molecule redox reagent known as Cleland's reagent. DTT's formula is C4H10O2S2 and the molecular structure of its reduced form is shown at the right; its oxidized form is a disulfide-bonded 6-membered ring (shown below). Its name derives from the four-carbon sugar, threose. DTT has an epimeric ('sister') compound, dithioerythritol (DTE).
DTT is an unusually strong reducing agent, because once oxidized, it forms a stable six-membered ring with an internal disulfide bond. It has a redox potential of -0.33 V at pH 7. The reduction of a typical disulfide bond proceeds by two sequential thiol-disulfide exchange reactions and is illustrated below. The reduction usually does not stop at the mixed-disulfide species because the second thiol of DTT has a high propensity to close the ring, forming oxidized DTT and leaving behind a reduced disulfide bond. The reducing power of DTT is limited to pH values above 7, since only the negatively charged thiolate form -S is reactive (the protonated thiol form -SH is not); the pKa of the thiol groups is 9.2 and 10.1.
A common use of DTT is as a reducing or "deprotecting" agent for thiolated DNA. The
Heme A (or haem A) is a heme, a coordination complex consisting of a macrocyclic ligand called a porphyrin, chelating an iron atom. Heme a is a biomolecule and is produced naturally by many organisms.
Heme A differs from heme B in that a methyl side chain at ring position 8 is oxidized to a formyl group and a hydroxyethylfarnesyl group, an isoprenoid chain, has been attached to the vinyl side chain at ring position 3 of the iron tetrapyrrole heme. Heme A is similar to heme o, in that both have this farnesyl addition at position 3 but heme O does not have the formyl group at position 8, still containing the methyl group. The correct structure of heme A, based upon NMR and IR experiments of the reduced, Fe(II), form of the heme, was published in 1975.
Heme A was first isolated by the great German biochemist Otto Warburg in 1951 and shown by him to be the active component of the integral membrane metalloprotein cytochrome c oxidase.
The final structural question of the exact geometric configuration about the first carbon at ring position 3 of ring I, the carbon bound to the hydroxyl group, has been recently published as the chiral S configuration.
Like heme B, heme A is often attached
Methyl iodide, also called iodomethane, and commonly abbreviated "MeI", is the chemical compound with the formula CH3I. It is a dense, colorless, volatile liquid. In terms of chemical structure, it is related to methane by replacement of one hydrogen atom by an atom of iodine. It is naturally emitted by rice plantations in small amounts. It is also produced in vast quantities estimated to be greater than 214,000 tons annually by algae and kelp in the world's temperate oceans and in lesser amounts on land due to terrestrial fungi and bacteria. It is used in organic synthesis as a source of methyl groups.
Methyl iodide had been approved for use as a pesticide by the United States Environmental Protection Agency in 2007 as a pre-plant biocide used to control insects, plant parasitic nematodes, soil borne pathogens, and weed seeds. The compound was registered for use as a preplant soil treatment for field grown strawberries, peppers, tomatoes, stone fruits, tree nuts, grape vines, ornamentals and turf and nursery grown strawberries, stone fruits, tree nuts, and conifer trees. After the discovery phase in a consumer lawsuit, the manufacturer withdrew the fumigant citing its lack of
Isocitric acid is a protonated form of isocitrate, which is a substrate of the citric acid cycle. Isocitrate is formed from citrate with the help of the enzyme aconitase, and is acted upon by isocitrate dehydrogenase. Salts and esters of isocitric acid are known as isocitrates.
Isocitric acid is commonly used as a marker to detect the authenticity and quality of fruit products, most often citrus juices. In authentic orange juice, for example, the ratio of citric acid to D-isocitric acid is usually less than 130. An isocitric acid value higher than this may be indicative of fruit juice adulteration.
Click on genes, proteins and metabolites below to link to respective articles.
Isopropylamine, also called 2-aminopropane, 2-propanamine, monoisopropylamine, and MIPA, is an organic compound, an amine. It is a base, as typical for amines. It is a hygroscopic colorless liquid with ammonia-like odor. Its melting point is −95.2°C and its boiling point is 32.4°C. It is miscible with water. It is extremely flammable, with flash point at −37°C.
pKa of protonated form is 10.63
Isopropylamine can be obtained by aminating isopropyl alcohol with ammonia in presence of a nickel/copper or similar catalyst:
The main uses of isopropylamine are in glyphosate herbicide formulations (e.g., Roundup or Vantage), a key component of atrazine (another herbicide), a regulating agent for plastics, intermediate in organic synthesis of coating materials, plastics, pesticides, rubber chemicals, pharmaceuticals and others, and as an additive in the petroleum industry.
Together with isopropyl alcohol it is used in some binary chemical weapons (e.g. M687), as a mixture called OPA which in turn mixed with methylphosphonyl difluoride (known to the military as DF) produces sarin gas.
Kainic acid is a natural marine acid present in some seaweed. It is a specific agonist for the kainate receptor used as an ionotropic glutamate receptor which mimics the effect of glutamate. Along with quisqualate, it is used in experiments to distinguish a receptor from the other ionotropic receptors for glutamate such as NMDA and AMPA.
In 1953, kainic acid was originally isolated from the seaweed called "Kainin-sou"(海人草) or "Makuri" (Digenea simplex) in Japan. "Kainin-sou" is used as an anthelmintic in Japan.
Kainic acid is a potent central nervous system stimulant, and has been developed as the prototype neuroexcitatory amino acid for the induction of seizures in experimental animals, at a typical dose of 10-30 mg/kg in mice. Kainic acid is neuroexcitotoxic and epileptogenic, acting through specific kainate receptors. Because of the supply shortage in 2000, the price of kainic acid has risen significantly.
Neosalvarsan is a synthetic chemotherapeutic that is an organoarsenic compound. It became available in 1912 and superseded the more toxic and less water-soluble salvarsan as an effective treatment for syphilis. Because both of these arsenicals carried considerable risk of side effects, they were replaced for this indication by penicillin in the 1940s.
Both salvarsan and neosalvarsan were developed in the laboratory of Paul Ehrlich in Frankfurt, Germany. Their discoveries were the result of the first organized team effort to optimize the biological activity of a lead compound through systematic chemical modifications. This scheme is the basis for most modern pharmaceutical research. Both salvarsan and neosalvarsan are prodrugs — that is, they are metabolised into the active drug in the body.
Diphenyl oxalate (trademark name Cyalume) is a solid ester whose oxidation products are responsible for the chemiluminescence in a glowstick. It can be synthesized by fully esterifying phenol with oxalic acid. The reaction with hydrogen peroxide that diphenyl oxalate undergoes to produce a photon of light is shown below:
The reaction rate is pH dependent, and slightly alkaline conditions achieved by adding a weak base, e.g., sodium salicylate, will produce brighter light. The 2,4,6-trichlorophenol ester of oxalic acid is a solid and thus easier to handle. Furthermore, since trichlorophenolate is the better leaving group, the reaction will proceed faster, again producing brighter light, as compared to the phenol ester.
The following colors can be produced by using different dyes:
Pterin is a heterocyclic compound composed of a pteridine ring system, with a keto group and an amino group on positions 4 and 2 respectively. Several tautomers of pterin exist and are shown below. Derivatives of pterin include pterins and folates.
Pterins, as a group, are compounds that are derivatives of the basic pterin structure, described in the beginning, with additional functional groups attached to the pyrazine subring. Pterins were first discovered in the pigments of butterfly wings (hence the origin of their name, from the Greek pteron (πτερόν), wing) and perform many roles in coloration in the biological world. Pterins also function as cofactors in enzyme catalysis.
Folates are “conjugated” pterins that contain p-aminobenzoic acid and L-glutamates connected to the methyl group at position 6 of the pteridine ring system. They are critical compounds in a large number of biological group transfer reactions. These folate-dependent biosynthetic reactions include the transfer of methyl groups from 5-methyltetrahydrofolate to homocysteine to form L-methionine, and the transfer of formyl groups from 10-formyltetrahydrofolate to L-methionine to form N-formylmethionine in
9,10-Bis(phenylethynyl)anthracene (BPEA) is an aromatic hydrocarbon with the chemical formula is C30H18. It displays strong fluorescence and is used as a chemiluminescent fluorophore with high quantum efficiency.
It is used in lightsticks as a fluorophor producing ghostly green light. It is also used as a dopant for organic semiconductors in OLEDs.
The emission wavelength can be lowered by substituting the anthracene core by halogens or alkyls. 2-ethyl and 1,2-dimethyl substituted BPEAs are also in use.
Carbendazim is a widely used, broad-spectrum benzimidazole fungicide and a metabolite of benomyl.
The fungicide is used to control plant diseases in cereals and fruits, including citrus, bananas, strawberries, pineapples, and pomes. It is also controversially used in Queensland, Australia on macadamia plantations.A 4.7% solution of carbendazim hydrochloride, sold as Eertavas, is marketed as a treatment for Dutch elm disease.
Studies have found high doses of carbendazim cause infertility and destroy the testicles of laboratory animals.
Maximum pesticide residue limits (MRLs) have reduced since discovering its harmful effects. The MRLs for fresh produce in the EU are now between 0.1 and 0.7 mg/kg with the exception of loquat, which is 2 mg/kg. The limits for more commonly consumed citrus and pomme fruits are between 0.1 and 0.2 mg/kg.
Pantetheine is the cysteamine amide analogue of pantothenic acid (vitamin B5). The dimer of this compound, pantethine is more commonly known, and is considered to be a more potent form of vitamin B5 than pantothenic acid. Pantetheine is an intermediate in the production of coenzyme A by the body.
1,3-Cyclohexadiene is a highly flammable cycloalkene that occurs as a colorless clear liquid. Its refractive index is 1.475 (20 °C, D).
It can be used as a hydrogen donor in transfer hydrogenation, since its conversion to benzene + hydrogen is in fact exothermic (about 20 kJ/mol in the gas phase, as indicated by heats of hydrogenation). Despite this apparent instability with respect to benzene, the 1,3-cyclohexadiene structure is found in several natural products such as α-terpinene.
Compared with 1,4-cyclohexadiene, 1,3-cyclohexadiene is about 1.6 kJ/mol less stable, due to the less favourable electronic distribution.
Azoxystrobin is a fungicide commonly used in agriculture. The substance is used as an active agent protecting plants and fruit/vegetables from fungal diseases.
Azoxystrobin was discovered during research on Oudemansiella mucida and Strobilurus tenacellus, which are small white or brown coloured mushrooms commonly found in the Czech forests. Not bigger than a few centimeters, these mushrooms attracted attention of scientists because of their remarkable ability to defend themselves. Their defense mechanism is based on the secretion of two substances, strobilurin A and oudemansin A. These substances allow them to keep their competitors at a distance and even destroy them when in range. Observations of this mechanism led directly to research that resulted in azoxystrobin.
After synthesizing experimental analogs of both substances (over 1400 were tested), azoxystrobin was found to be the most active and stable combination. The pharmacophore of azoxystrobine is the β-methoxyacrylate portion, which is present in the active compounds from both Oudemansiella mucida and Strobilurus tenacellus. Azoxystrobin binds very tightly to the Qo site of Complex III of the mitochondrial electron
Ethylamine is an organic compound with the formula CH3CH2NH2. This colourless gas has a strong ammonia-like odor. It is miscible with virtually all solvents and is a weak base, as is typical for amines. Ethylamine is widely used in chemical industry and organic synthesis.
pKa (of protonated form) = 10.7
Ethylamine is produced on a large scale by two processes. Most commonly ethanol and ammonia are combined in the presence of an oxide catalyst:
In this reaction, ethylamine is coproduced together with diethylamine and triethylamine. In aggregate, approximately 80M kilograms/year of these three amines are produced industrially. It is also produced by reductive amination of acetaldehyde.
Ethylamine can be prepared by several other routes, but these are not economical. Ethylene and ammonia combine to give ethylamine in the presence of an sodium amide or related basic catalysts.
Hydrogenation of acetonitrile, acetamide, and nitroethane affords ethylamine. These reactions can be effected stoichiometrically using lithium aluminium hydride. In another route, ethylamine can be synthesized via nucleophilic substitution of a haloethane (such as chloroethane or bromoethane) with ammonia,
Genipin is a chemical compound found in gardenia fruit extract. It is an aglycone derived from an iridoid glycoside called geniposide present in fruit of Gardenia jasminoides.
Genipin is an excellent natural cross-linker for proteins, collagen, gelatin, and chitosan cross-linking. It has a low acute toxicity, with LD50 i.v. 382 mg/kg in mice, therefore, much less toxic than glutaraldehyde and many other commonly used synthetic cross-linking reagents. Furthermore, genipin can be used as a regulating agent for drug delivery, as the raw material for gardenia blue pigment preparation, and as the intermediate for alkaloid syntheses.
In vitro experiments have shown that genipin blocks the action of the enzyme uncoupling protein 2.
Lyxose is an aldopentose — a monosaccharide containing five carbon atoms, and including an aldehyde functional group. It has chemical formula C5H10O5.
Lyxose occurs only rarely in nature, for example, as a component of bacterial glycolipids.
Mecoprop, or methylchlorophenoxypropionic acid (MCPP), is a common general use herbicide found in many household weed killers and "weed-and-feed" type lawn fertilizers. It is primarily used to control broadleaf weeds. It is often used in combination with other chemically related herbicides such as 2,4-D, dicamba, and MCPA.
Mecoprop is a mixture of two stereoisomers, with the (R)-(+)-enantiomer ("Mecoprop-P", "Duplosan KV") possessing the herbicidal activity.
The United States Environmental Protection Agency has classified mecoprop as toxicity class III - slightly toxic.
Urobilin is a yellow linear tetrapyrrole, resulting from the breakdown of heme, a cyclic tetrapyrrole. It is primarily responsible for the yellow color of urine. Urobilin is produced when Urobilinogen is oxidized, by intestinal bacteria or by exposure to the environment upon urination.
Many urine tests (urinalysis) monitor the amount of urobilin in urine because it is an important substance in metabolism, production of urine. Urobilin levels can give insight on the effectiveness of urinary tract function. Normally, urine would appear as either light yellow urine or colorless. The yellow in the urine is from the presence of urobilin. If there are other chemicals in the urine, the appearance of the urine can darken, or it can appear cloudy in case particles are present, or simply orange urine in case of dehydration.
Darker urine is not necessarily a sign of illness. A lack of water intake, for example following sleep or dehydration, reduces the water content of urine, thereby concentrating urobilin and producing a darker color of urine. Of course, urine can appear amber or red when red blood cells are present in urine, which is a condition called hematuria. .
Acetanisole is an aromatic chemical compound with an aroma described as butter, caramel, fruity, nutty, sweet, and vanilla. It is used as a cigarette additive, a fragrance,, and a flavoring in food.
Acetanisole is found naturally in castoreum, the glandular secretion of the beaver.
Acetanisole can be prepared synthetically by Friedel-Crafts acylation of anisole with acetyl chloride:
Bipyridines are a family of chemical compounds with the formula (C5H4N)2, which are formed by the coupling of two pyridine rings. Six isomers of bipyridine exist, but two isomers are prominent: 2,2'-bipyridine is a popular ligand in coordination chemistry and 4,4'-bipyridine is a precursor to the herbicide paraquat. The bipyridines are colourless solids, which are soluble in organic solvents and slightly soluble in water.
The 3,4'-Bipyridine derivatives inamrinone and milrinone are used occasionally for short term treatment of congestive heart failure. They inhibit phosphodiesterase and thus increasing cAMP, exerting positive inotropy and causing vasodilation. Inamrinone causes thrombocytopenia. Milrinone decreases survival in heart failure.
2,2'-bipyridine is a chelating ligand that forms complexes with most transition metal ions. Many of these complexes have distinctive optical properties and some are of interest for analysis. 2,2'-Bipyridine is used in the manufacture of Diquat.
4,4'-Bipyridine (4,4'-bipy) is mainly used as a precursor to the N,N'-dimethyl-4,4'-bipyridinium dication commonly known as paraquat. This species is redox active, and its toxicity arises from its
Copper(II) aspirinate is an aspirin chelate of copper(II) cations (Cu). It is used to treat rheumatoid arthritis.
Copper aspirinate can be prepared by several methods. In one route of preparation, an excess of acetylsalicylic acid is dissolved in aqueous sodium carbonate. Sodium hydroxide is not suitable for this purpose, because it will hydrolyse acetylsalicylic acid (ASA) into salicylic acid and sodium acetate.
The resulting solution is then filtered to remove any undissolved acetylsalicylic acid and is mixed with a solution containing Cu cations (copper(II) sulfate is suitable), precipitating bright blue crystals of copper aspirinate immediately. The crystals can then be filtered from solution, washed, and dried. An excess of acetylsalicylic acid is used in the first step, because it eliminates the possibility of unreacted carbonate anions precipitating the copper in this step.
Copper aspirinate has been proven effective as a treatment for rheumatoid arthritis. The studies on animal models suggest that copper aspirinate is very promising in treating against thrombotic diseases and it has all the prospects of success in becoming an antithrombotic drug that prevents and treats
Femoxetine (Malexil, FG-4963) is a drug related to paroxetine that was being developed as an antidepressant by the pharmaceutical company Ferrosan in 1974. It functions as a selective serotonin reuptake inhibitor (SSRI). Development was halted for unknown reasons, perhaps to focus attention on paroxetine instead.
Dr. Jorgen Buus-Lassen of Ferrosan invented both femoxetine and paroxetine in the 1970s.
Hasubanonine is a member of the hasubanan family of alkaloids. The alkaloid with an isoquinoline substructure has the molecular formula of C21H27NO5. The enantiomer of the natural product is being studied as a potential painkiller.
Nitrofural (INN, trade name Furacin) is a bactericidal compound used as an antibiotic most commonly in the form of ointments. Its use in medicine has become less frequent as safer and more effective products have become available, and it has been discontinued in the US. The substance is pale yellow and crystalline.
Other names include nitrofurazone and furacilin.
Pyrazine is a heterocyclic aromatic organic compound with the chemical formula C4H4N2.
Pyrazine is a symmetrical molecule with point group D2h. Derivatives such as phenazine are well known for their antitumor, antibiotic and diuretic activities. Pyrazine is less basic in nature than pyridine, pyridazine and pyrimidine. Tetramethylpyrazine (also known as ligustrazine) is reported to scavenge superoxide anion and decrease nitric oxide production in human polymorphonuclear leukocytes, and is a component of some herbs in traditional Chinese medicine.
Many methods exist for the organic synthesis of pyrazine and its derivatives. Some of these are among the oldest synthesis reactions still in use.
In the Staedel-Rugheimer pyrazine synthesis (1876) 2-chloroacetophenone is reacted with ammonia to the amino ketone, then condensed and then oxidized to a pyrazine A variation is the Gutknecht pyrazine synthesis (1879) also based on this selfcondensation, but differing in the way the alpha-ketoamine is synthesised
The Gastaldi synthesis (1921) is another variation :
Sorbose is a ketose belonging to the group of sugars known as monosaccharides. It has a sweetness that is equivalent to sucrose (table sugar). The commercial production of vitamin C (ascorbic acid) often begins with sorbose. L-Sorbose is the configuration of the naturally occurring sugar.
2,4-Dichlorobenzyl alcohol is a mild antiseptic, able to kill bacteria and viruses associated with mouth and throat infections. It is a common ingredient in throat lozenges such as Strepsils or Gorpils. A low-pH throat lozenge containing dichlorobenzyl alcohol (1.2 mg) and amylmetacresol (600μg) has been found to deactivate Respiratory syncytial virus and SARS-Cov, but not adenovirus or rhinovirus. A dentifrice containing 10% sodium benzoate and 0.3% dichlorobenzyl alcohol maintains antimicrobial activity for 5–10 minutes after brushing.
Benzoic acid (pronunciation: /bɛnˈzoʊ.ɪk/), C7H6O2 (or C6H5COOH), is a colorless crystalline solid and a simple aromatic carboxylic acid. The name derived from gum benzoin, which was for a long time the only source for benzoic acid. Its salts are used as a food preservative and benzoic acid is an important precursor for the synthesis of many other organic substances. The salts and esters of benzoic acid are known as benzoates (pronunciation: /ˈbɛnzoʊ.eɪt/).
Benzoic acid was discovered in the sixteenth century. The dry distillation of gum benzoin was first described by Nostradamus (1556), and subsequently by Alexius Pedemontanus (1560) and Blaise de Vigenère (1596).
Pioneer work in 1830 through a variety of experiences based on amygdalin, obtained from bitter almonds (the fruit of Prunus dulcis) oil by Pierre Robiquet and Antoine Boutron-Charlard, two French chemists, had produced benzaldehyde but they failed in working out a proper interpretation of the structure of amygdalin that would account for it, and thus missed the identification of the benzoyl radical C7H5O. This last step was achieved some few months later (1832) by Justus von Liebig and Friedrich Wöhler, who determined
Cytosine (C) is one of the four main bases found in DNA and RNA, along with adenine, guanine, and thymine (uracil in RNA). It is a pyrimidine derivative, with a heterocyclic aromatic ring and two substituents attached (an amine group at position 4 and a keto group at position 2). The nucleoside of cytosine is cytidine. In Watson-Crick base pairing, it forms three hydrogen bonds with guanine.
Cytosine was discovered by Albrecht Kossel in 1894 when it was hydrolysed from calf thymus tissues. A structure was proposed in 1903, and was synthesized (and thus confirmed) in the laboratory in the same year.
Cytosine recently found use in quantum computation. The first time any quantum mechanical properties were harnessed to process information took place on August 1 in 1998 when researchers at Oxford implemented David Deutsch's algorithm on a two qubit NMRQC (Nuclear Magnetic Resonance Quantum Computer) based on the cytosine molecule.
Cytosine can be found as part of DNA, as part of RNA, or as a part of a nucleotide. As cytidine triphosphate (CTP), it can act as a co-factor to enzymes, and can transfer a phosphate to convert adenosine diphosphate (ADP) to adenosine triphosphate (ATP).
Dequalinium is a quaternary ammonium cation commonly available as the dichloride salt. The bromide, iodide, acetate, and undecenoate salts are known as well. Dequalinium chloride is the active ingredient of several medications:
Dequadin an antiseptic and disinfectant. It is a topical bacteriostat. It is used in wound dressings and mouth infections and may also have antifungal action. It may cause skin ulceration.
Fluomizin, vaginal tablets containing 10 mg dequalinium chloride, are used for treating vaginal bacterial conditions (i.e. Bacterial Vaginosis).
The dequalinium dication is symmetrical, containing two quaternary quinolinium units linked by a dodecylene chain.
Dequalinium salts may be used to treat malaria. As dequalinium chloride, it can be used in lozenges to cure sore throats however while this is effective in vitro, it is not effective in cases of streptococci infections
Diisobutyl Phthalate (DIBP) is prepared by esterification process of isobutanol and phthalic anhydride. Its structural formula is C6H4(COOCH2CH(CH3)2)2. Refractive index is 1.488 - 1.492 (20 °C, D).
DIBP is an odorless plasticizer and has excellent heat and light stability. It is the lowest cost plasticizer for cellulose nitrate. DIBP has lower density and freezing point than DBP (dibutyl phthalate, CAS No.: 84-74-2). It has similar properties as dibutyl phthalate and can be used as a substitute for it.
DIBP is used in nitro cellulose plastic, nail polish, explosive material, lacquer manufacturing and used with methyl methacrylate applications.
The concentration of a metabolite of DIBP (Mono-isobutyl phthalate or MIBP) has been steadily increasing in the urine of Americans over the period 1999-2008.
Products in Taiwan made from Hebo Natural Products Limited (禾博天然產物有限公司) of China contained ginger contaminated with DIBP, some 80,000 nutritional supplement capsules made with imported ginger powder were seized by the Public Health Department of Taiwan in June 2011. In addition, soybean extract and olive leaf extract, both in powder form, were contaminated with DIBP and DBP.
Gluconic acid is an organic compound with molecular formula C6H12O7 and condensed structural formula HOCH2(CHOH)4COOH. It is one of the 16 stereoisomers of 2,3,4,5,6-pentahydroxyhexanoic acid.
In aqueous solution at neutral pH, gluconic acid forms the gluconate ion. The salts of gluconic acid are known as "gluconates". Gluconic acid, gluconate salts, and gluconate esters occur widely in nature because such species arise from the oxidation of glucose. Some drugs are injected in the form of gluconates.
The chemical structure of gluconic acid consists of a six-carbon chain with five hydroxyl groups terminating in a carboxylic acid group. In aqueous solution, gluconic acid exists in equilibrium with the cyclic ester glucono delta-lactone.
Gluconic acid occurs naturally in fruit, honey, kombucha tea, and wine. As a food additive (E574), it is an acidity regulator. It is also used in cleaning products where it dissolves mineral deposits especially in alkaline solution. The gluconate anion chelates Ca, Fe, Al, and other metals. In 1929 Horace Terhune Herrick developed a process for producing the salt by fermentation.
Calcium gluconate, in the form of a gel, is used to treat burns from
Ponceau 2R, Xylidine ponceau, Ponceau G, Red R, Acid Red 26, Food Red 5, or C.I. 16150 is a red azo dye used in histology for staining. It is easily soluble in water and slightly in ethanol. It usually comes as a disodium salt.
Xylidine ponceau is mostly used only in the Masson's trichrome stain as a red counterstain, where it imparts orange hue to the red-stained cytoplasmic structures.
Its other names are: Acetacid red J, Acidal ponceau G, Acid leather red KPR, Acid leather red P2R, Acid leather scarlet IRW, Acid ponceau R, Acid ponceau 2RL, Acid ponceau special, Acid scarlet, Acid scarlet 2RL, Acid scarlet 2RN, Acilan ponceau RRL, Ahcocid fast scarlet R, Aizen ponceau RH, Amacid lake scarlet 2R, Amacid scarlet 2R, Brilliant ponceau G, Calcocid 2RIL, Calcocid scarlet 2R, Calcocid scarlet 2RIL, Calcolake scarlet 2R, Certicol ponceau MXS, C.I. Acid red 26, C.I. Food red 5, Colacid ponceau special, Comacid scarlet 2R D and C red No. 5, Edicol supra ponceau R, Fenazo scarlet 2R, Hexacol ponceau MX, Hexacol ponceau 2R, Hidacid scarlet 2R, Hispacid ponceau R, Java ponceau 2R, Kiton ponceau R, Kiton scarlet 2RC, Lake ponceau, Lake scarlet R, Lake scarlet 2RBN, Naphthalene lake scarlet
Butane is a gas with the formula C4H10 that is an alkane with four carbon atoms. The term may refer to either of two structural isomers, n-butane or isobutane (or "methylpropane"), or to a mixture of these isomers. In the IUPAC nomenclature, however, "butane" refers only to the n-butane isomer (which is the isomer with the unbranched structure). Butanes are highly flammable, colorless, easily liquefied gases. The name butane comes from the roots but- (from butyric acid) and -ane.
Rotation about the central C-C bond produces two different conformations (trans and gauche) for n-butane.
When oxygen is plentiful, butane burns to form carbon dioxide and water vapor; when oxygen is limited, carbon (soot) or carbon monoxide may also be formed.
The maximum adiabatic flame temperature of butane with air is 2,243 K (1,970 °C; 3,578 °F).
n-Butane is the feedstock for DuPont's catalytic process for the preparation of maleic anhydride:
n-Butane, like all hydrocarbons, undergoes free radical chlorination providing both 1-chloro- and 2-chlorobutanes, as well as more highly chlorinated derivatives. The relative rates of the chlorination is partially explained by the differing bond dissociation
Cyclen or 1,4,7,10-tetraazacyclododecane is a macrocycle and the aza analogue of the crown ether 12-crown-4. Derivatives of cyclen are larger cyclic polyamines but the repeating unit (ethyleneimine) is always the same. Like crown ethers, cyclen compounds are capable of selectively binding cations. They are used as a ligand in chemistry for instance with chemicals used in MRI contrast agents.
Cyclen compounds can be synthesized by combining two separate parts by nucleophilic displacement. In this procedure the terminal amine groups in diethylene triamine (1) are activated as amine anionic nucleophiles by reaction with tosyl chloride in pyridine to the N-tosyl protective group followed by proton abstraction with sodium ethoxide. The alcohol end groups in diethanolamine (2) are activated as electrophile by converting them into tosyl leaving groups. The two segments are joined in dimethylformamide and unless the reactants are very diluted, ordinary polymerization will take place to long linear chains and not cyclization. In the final step the tosyl groups are removed with sulfuric acid.
High dilution conditions result in a low reaction rate penalty and this disadvantage is removed in
Dibromomethane or methylene bromide, or methylene dibromide is a halomethane. It is slightly soluble in water, but very soluble in carbon tetrachloride, diethyl ether and methanol. Its refractive index is 1.5419 (20 °C, D).
Dibromomethane can be prepared from bromoform by reaction
using sodium arsenite and sodium hydroxide.
Another way is to prepare it from diiodomethane and bromine.
Dibromomethane is used as a solvent, gauge fluid, and in organic synthesis. It is a convenient agent for converting catechols to their methylenedioxy- derivatives.
It is naturally produced by marine algae and liberated to the oceans. Releasing on soil causes it to evaporate and leach into the ground. Releasing in water causes it to be lost mainly by volatilisation with a half life of 5.2 hours. It has no significant degradating biological or abiological effects. In the atmosphere it will be lost because of reaction with photochemically produced hydroxyl radicals. The estimated half life of this reaction is 213 days.
Diphenylmethane is an organic compound with the formula (C6H5)2CH2. The compound consists of methane wherein two hydrogen atoms are replaced by two phenyl groups. Diphenylmethane forms a common skeleton in organic chemistry; the diphenylmethyl group is also known as benzhydryl.
It is prepared by the reaction of benzyl chloride with benzene in the presence of a Lewis acid such as aluminium trichloride:
Geranylgeranyl pyrophosphate is an intermediate in the HMG-CoA reductase pathway used by organisms in the biosynthesis of terpenes and terpenoids. In plants it is also the precursor to carotenoids, gibberellins, tocopherols, and chlorophylls.
It is also a precursor to geranylgeranylated proteins.
In Drosophila, geranylgeranyl pyrophosphate is synthesised by HMG-CoA encoded by the Columbus gene. Geranylgeranyl pyrophosphate is utilised as a chemoattractant for migrating germ cells which have traversed the midgut epithelia. The attractant signal is produced at the gonadal precursors, directing the germ cells to these sites, where they will differentiate into ova (eggs) and spermatazoa (sperm).
Methyl carbamate (also called methylurethane, or urethylane) is an organic compound and the simplest ester of the hypothetical carbamic acid (NH2COOH). Its sum formula is C2H5NO2.
Methyl carbamate is formed by the reaction of ammonia with methyl chloroformate or methyl carbonate. According to United States patent number 2834799 urea can be reacted with methanol to form it using boron trifluoride as a reagent. Unlike its close relative ethyl carbamate it is not mutagenic in salmonella (it tested negative in the Ames test), but it is mutagenic in Drosophila. Experimental evidence does show that it is a carcinogen in rat, and not carcinogenic in mice. The compound is "known to the state of California to cause cancer" per Proposition 65.
The compound was detected in wines preserved with dimethyl dicarbonate.
Methyl carbamate is used by the textile industry to manufacture resins to be applied on polyester/cotton blend fabrics as durable-press finishes.
N-Methyl carbamates are widely used as insecticides. They have anticholinesterase activity without a cumulative effect.
N-Phenethyl-4-piperidone (NPP) is a derivative of 4-piperidone with the molecular formula C13H17NO. 4-Piperidone is used as an intermediate in the manufacture of chemicals and pharmaceutical drugs such as fentanyl.
Because of its possible use in the illicit manufacture of fentanyl, NPP was placed onto the list of controlled chemicals in the USA in 2007, and possession and sales of this compound are now restricted.
The synthesis of N-phenethyl-4-piperidone cannot be prepared via the simple SN2 substitution reaction reported on the web using 4-piperidone with phenethyl bromide in the presence of a phase transfer catalyst. Its preparation requires sophisticated laboratory equipment and considerable knowledge and skill with organic chemistry.
N-Phenethyl-4-piperidone is useful in the synthesis of pharmaceuticals, primarily fentanyl and its analogs. Paul Janssen (founder of Janssen Pharmaceutica) first synthesized fentanyl in 1960 from NPP. Janssen's synthesis involved reacting N-Phenethyl-4-piperidone with aniline, and then reducing the imine product with sodium borohydride to 4-anilino-N-phenethylpiperidine (ANPP). This product is reacted with propionyl chloride to form fentanyl.
Nordihydrocapsaicin is a capsaicinoid and analog and congener of capsaicin in chili peppers (Capsicum).
Like capsaicin, it is an irritant. Nordihydrocapsaicin accounts for about 7% of the total capsaicinoids mixture and has about half the pungency of capsaicin. Pure nordihydrocapsaicin is a lipophilic colorless odorless crystalline to waxy compound. On the Scoville scale it has 9,100,000 SHU (Scoville heat units), significantly higher than pepper spray.
Pepstatin is a potent inhibitor of aspartyl proteases. It is a hexa-peptide containing the unusual amino acid statine (Sta, (3S,4S)-4-amino-3-hydroxy-6-methylheptanoic acid), having the sequence Isovaleryl-Val-Val-Sta-Ala-Sta (Iva-Val-Val-Sta-Ala-Sta). It was originally isolated from cultures of various species of Actinomyces due to its ability to inhibit pepsin at picomolar concentrations. Pepstatin A is well known to be an inhibitor of aspartic proteinases such as pepsin, cathepsins D and E. Except for its role as a proteinase inhibitor, however, the pharmacological action of pepstatin A upon cells remain unclear. Pepstatin A suppresses receptor activator of NF-κB ligand (RANKL)–induced osteoclast differentiation. Pepstatin A suppresses the formation of multinuclear osteoclasts dose-dependently. This inhibition of the formation only affected osteoclast cells, i.e., not osteoblast-like cells. Furthermore, pepstatin A also suppresses differentiation from pre-osteoclast cells to mononuclear osteoclast cells dose-dependently. This inhibition seems to be independent of the activities of proteinases such as cathepsin D, because the formation of osteoclasts was not suppressed with the
Porphobilinogen (PBG) is a pyrrole involved in porphyrin metabolism.
It is generated by aminolevulinate (ALA) and the enzyme ALA dehydratase. PBG is then converted into hydroxymethyl bilane by the enzyme porphobilinogen deaminase, also known as hydroxymethylbilane synthase.
Acute intermittent porphyria causes an increase in urinary porphobilinogen.
Ribulose is a ketopentose — a monosaccharide containing five carbon atoms, and including a ketone functional group. It has chemical formula C5H10O5. Two enantiomers are possible, D-ribulose (D-erythro-pentulose) and L-ribulose (L-erythro-pentulose). D-Ribulose is the diastereomer of D-xylulose.
Ribulose sugars are composed in the pentose phosphate pathway. They are important in the formation of many bioactive substances. For example, D-ribulose is an intermediate in the fungal pathway for D-arabitol production. Also, as the 1,5-bisphosphate, D-ribulose combines with carbon dioxide at the start of the photosynthesis process in green plants (carbon dioxide trap).
A synthetic form of ribulose known as sucroribulose is found in many brands of artificial sweeteners.
Ruthenocene is an organoruthenium compound with the formula (C5H5)2Ru. This pale yellow, volatile solid is classified as a sandwich compound and more specifically, as a metallocene.
Ruthenocene consists of a ruthenium ion sandwiched in between two cyclopentadienyl rings. It features ruthenium centre bound symmetrically to the planes of two cyclopentadienyl rings. It is closely related to the isoelectronic ferrocene.
In contrast to ferrocene, wherein the cyclopentadienyl rings are in a staggered conformation, those of ruthenocene crystallise with an eclipsed conformation. This difference is due to the larger ionic radius of ruthenium, which increases the distance between the cyclopentadienyl rings, decreasing steric interactions and allowing an eclipsed conformation to prevail. In solution, these rings rotate with a very low barrier.
Ruthenocene was first synthesized in 1952 by Geoffrey Wilkinson, a Nobel laureate who had collaborated in assigning the structure of ferrocene only a year earlier. Originally, ruthenocene was prepared by the reaction of ruthenium trisacetylacetonate with excess of cyclopentadienylmagnesium bromide.
Ruthenocene may also be prepared by the reaction of