nucleoside phosphate

A nucleobase-containing molecular entity that is a nucleoside in which one or more of the sugar hydroxy groups has been converted into a mono- or poly-phosphate. The term includes both nucleotides and non-nucleotide nucleoside phosphates.


2-hydroxylaminobenzoic acid

An  aminobenzoic acid that is benzoic acid substutited by a hydroxyamino group at position 2.


2-nitrobenzoic acid

A nitrobenzoic acid carrying the nitro substituent at position 2.


orthoquinones

Any quinone in which the carbons of the two carbonyl groups in the quinone system are joined to each other by a single bond.


octadecadienoate

A long-chain, unsaturated fatty acid anion formed by deprotonation of the carboxy group of any octadecadienoic acid; major species at pH 7.3.


octadecadienoic acid

Any straight-chain, C18 polyunsaturated fatty acid having two C=C double bonds.


octadecanoate

A fatty acid anion 18:0 that is the conjugate base of octadecanoic acid (stearic acid). Stearates have a variety of uses in the pharmaceutical industry.


octadecatrienoic acid

Any trienoic fatty acid having eighteen carbons.


octadecenoic acid

Any member of the group of C18 monounsaturated fatty acids with the double bond located at any position in the chain.


octadecenynoic acid

Any C18 polyunsaturated fatty acid containing one C=C and one C#C bond.


octadienol

A primary alcohol that is octanol consisting of two double bonds at unspecified positions.


aldrin

An organochlorine compound resulting from the Diels-Alder reaction of hexachlorocyclopentadiene with norbornadiene. A proinsecticide (by epoxidation of the non-chlorinated double bond to give dieldrin), it was widely used as an insecticide before being banned in the 1970s as a persistent organic pollutant.


octamethylcyclotetrasiloxane

A cyclosiloxane that is the octamethyl derivative of  cyclotetrasiloxane.


octanoate

A straight-chain saturated fatty acid anion that is the conjugate base of octanoic acid (caprylic acid); believed to block adipogenesis.


octanoyl group

The univalent carboacyl group formed by loss of -OH from the carboxy group of octanoic acid.


octatrienoic acid

Any medium-chain fatty acid with eighteen carbons and three double bonds.


octose

An eight-carbon monosaccharide which in its linear form contains either an aldehyde group at position 1 (aldooctose) or a ketone group at position 2 (ketooctose).


alendronate

A 1,1-bis(phosphonic acid) that is methanebis(phosphonic acid) in which the two methylene hydrogens are replaced by hydroxy and 3-aminopropyl groups.


oligomycin

Any of the 26-membered ring macrolides produced by Streptomyces species that can be toxic to other organisms through their ability to inhibit mitochondrial membrane-bound ATP synthases.


SDMA

A  L-arginine derivative having two methyl groups at the N(omega)- and N'(omega)-positions


alfentanil

A member of the class of piperidines that is piperidine having a 2-(4-ethyl-5-oxo-4,5-dihydro-1H-tetrazol-1-yl)ethyl group at the 1-position as well as N-phenylpropanamido- and methoxymethyl groups at the 4-position.


organic anion

Any organic ion with a net negative charge.


organic cation

Any organic ion with a net positive charge.


ether

An organooxygen compound with formula ROR, where R is not hydrogen.


organic oxide

An oxide in which the oxygen atom is bonded to a carbon atom.


organic peroxide

Compounds of structure ROOR' in which R and R' are organic groups.


organic sulfate

Compounds of the general formula SO3HOR where R is an organyl group


organochlorine insecticide

Any organochlorine pesticide that has been used as an insecticide.


organomercury compound

A compound containing at least one carbon-mercury bond.


organometallic compound

A compound having bonds between one or more metal atoms and one or more carbon atoms of an organyl group.


aliphatic alcohol

An  alcohol derived from an aliphatic compound.


organophosphorus compound

An organophosphorus compound is formally a compound containing at least one carbon-phosphorus bond, but the term is often extended to include esters and thioesters.


organoselenium compound

An organoselenium compound is a compound containing at least one carbon-selenium bond.


organosilicon compound

An organosilicon compound is a compound containing at least one carbon-silicon bond.


organothiophosphorus compound

An organothiophosphorus compound is an organophosphorus compound which contains a phosphorus-sulfur bond.


ornithine derivative

A non-proteinogenic amino acid derivative resulting from reaction of ornithine at the amino group, the carboxy group, or the side-chain amino group, or from the replacement of any hydrogen of ornithine by a heteroatom. The definition normally excludes peptides containing ornithine residues.


orotidine

A nucleoside formed by attaching orotic acid to a ribose ring via a beta-N(1)-glycosidic bond.


oxide

An oxide is a chemical compound of oxygen with other chemical elements.


oxime

Compounds of structure R2C=NOH derived from condensation of aldehydes or ketones with hydroxylamine. Oximes from aldehydes may be called aldoximes; those from ketones may be called ketoximes.


oxo carboxylic acid

Any compound that has an aldehydic or ketonic group as well as a carboxylic acid group in the same molecule.


oxopentanoates

The conjugate base of any oxopentanoic acid.


oxopentanoic acid

A C5 fatty acid carrying an oxo group at any position.


unsaturated fatty acid anion

Any fatty acid anion containing at least one C-C unsaturated bond; formed by deprotonation of the carboxylic acid moiety.


oxoproline

A pyrrolidinemonocarboxylic acid consisting of proline bearing a single oxo substituent.


OZONE

An elemental molecule with formula O3. An explosive, pale blue gas (b.p. -112degreeC) that has a characteristic, pungent odour, it is continuously produced in the upper atmosphere by the action of solar ultraviolet radiation on atmospheric oxygen. It is an antimicrobial agent used in the production of bottled water, as well as in the treatment of meat, poultry and other foodstuffs.


p-cumate

A cumate that is the conjugate base of p-cumic acid.


p-quinones

A quinone in which the two oxo groups of the quinone are located para to each other on the 6-membered quinonoid ring.


hexadecanoate ester

A fatty acid ester obtained by condensation of the carboxy group of palmitic acid with a hydroxy group of an alcohol or phenol.


practolol

N-(4-Hydroxyphenyl)acetamide in which the hydrogen of the phenolic hydroxy group is substituted by a 3-(isopropylaminoamino)-2-hydroxypropyl group. A selective beta blocker, it has been used in the emergency treatment of cardiac arrhythmias.


pantothenic acids

A class of amides formed from pantoic acid and beta-alanine and its derivatives.


PARAXANTHINE

A dimethylxanthine having the two methyl groups located at positions 1 and 7. It is a metabolite of caffeine and theobromine in animals.


PELARGONIDIN

An anthocyanidin cation that is flavylium substituted by a hydroxy groups at positions 3, 5, 7 and 4'.


pentadienoic acid

Any 5-carbon fatty acid containing two double bonds.


PENTAERYTHRITYL DINITRATE

A pentaerythritol nitrate in which two of the hydroxy groups of pentaerythritol have been converted to the corresponding nitrate ester.


pentaerithrityl tetranitrate

A pentaerythritol nitrate in which all four hydroxy groups of pentaerythritol have been converted to the corresponding nitrate ester. It is a vasodilator with properties similar to those of glyceryl trinitrate, but with a more prolonged duration of action, and is used for treatment of angina pectoris. It is also one of the most powerful high explosives known and is a component of the plastic explosive known as Semtex.


pentahydroxycyclohexanone

A hydroxycyclohexanone bearing five hydroxy substituents.


dihydrotricetin

A pentahydroxyflavanone that is flavanone substituted by hydroxy groups at positions 5, 7, 3', 4' and 5'.


pentahydroxyflavone

A hydroxyflavone substituted by five hydroxy groups.


name: pentakis-L-cysteinyl L-histidino nickel tetrairon pentasulfide


pentanone

Any ketone that is pentane substituted by an oxo group at unspecified position.


pentenoic acid

Any C5, straight-chain, monounsaturated fatty acid.


pentitol

An alditol obtained by reduction of any pentose.


pentose

A five-carbon monosaccharide which in its linear form contains either an aldehyde group at position 1 (aldopentose) or a ketone group at position 2 (ketopentose).


peroxides

Compounds of structure ROOR'.


peroxynitrite

The nitrogen oxoanion formed by loss of a proton from peroxynitrous acid.


pesticide synergist

A substance that increases the efficacy of a pesticide.


pesticide

Strictly, a substance intended to kill pests. In common usage, any substance used for controlling, preventing, or destroying animal, microbiological or plant pests.


alliin

An L-alanine derivative in which one of the methyl hydrogens of L-alanine has been replaced by an (S)-allylsulfinyl group.


phenanthrenes

Any benzenoid aromatic compound that consists of a phenanthrene skeleton and its substituted derivatives thereof.


phenylacetic acids

Any monocarboxylic acid that is phenylacetic acid or its substituted derivatives.


phenylacetonitrile

A nitrile that is acetonitrile where one of the methyl hydrogens is substituted by a phenyl group.


phenylalanine derivative

An amino acid derivative resulting from reaction of alanine at the amino group or the carboxy group, or from the replacement of any hydrogen of phenylalanine  by a heteroatom. The definition normally excludes peptides containing phenylalanine  residues.


phenylethanolamines

An ethanolamine compound having a phenyl (substituted or unsubstituted) group on the carbon bearing the hydroxy substituent.


phenylhydrazines

Any member of the class of  hydrazines carrying a phenyl substituent.


3-phenyllactic acid

A 2-hydroxy monocarboxylic acid that is lactic acid in which one of the methyl hydrogens is substituted by a phenyl group.


(+)-iridodial lactol

An iridoid monoterpenoid that is 1,4a,5,6,7,7a-hexahydrocyclopenta[c]pyran substituted by methyl groups at positions 4 and 7 and a hydroxy group at position 1 (the 1R,4aS,7S,7aR-stereoisomer).


methylcarbamoylcarbamate

A  carbamate ester obatined by the formal condensation of  urea-1-carboxylic acid with methanol.


phenylpropanoid

Any organic aromatic compound with a structure based on a phenylpropane skeleton. The class includes naturally occurring phenylpropanoid esters, flavonoids, anthocyanins, coumarins and many small phenolic molecules as well as their semi-synthetic and synthetic analogues. Phenylpropanoids are also precursors of lignin.


phenylpyruvate

A 2-oxo monocarboxylic acid anion resulting from deprotonation of the carboxy group of either keto- or enol-phenylpyruvic acid.


pheromone

A semiochemical used in olfactory communication between organisms of the same species eliciting a change in sexual or social behaviour.


phosphatidyl group

An acyl group derived from a phosphatidic acid.


phosphatidylinositol 3-phosphate

A phosphatidylinositol monophosphate carrying the phosphate group at the 3-position.


phosphonic acids

HP(=O)(OH)2  (phosphonic acid) and its P-substituted derivatives.


ALOE-EMODIN

A dihydroxyanthraquinone that is  chrysazin carrying a hydroxymethyl group at position 3. It has been isolated from plant species of the genus Aloe.


phosphoric acid

A phosphorus oxoacid that consists of one oxo and three hydroxy groups joined covalently to a central phosphorus atom.


benzenedicarboxylic acid

A member of the class of benzoic acids in that consists of benzene substituted by two carboxy groups (A closed class).


phthaloyl group

A divalent carboacyl group formed by removal of an OH from each carboxyl group of phthalic acid. It has been used as an amino protecting group of deoxyadenosine in oligonucleotide synthesis.


phthalyl group

A univalent carboacyl group formed by removal of an OH from one of the carboxyl groups of phthalic acid.


alprazolam

A member of the class of triazolobenzodiazepines that is 4H-[1,2,4]triazolo[4,3-a][1,4]benzodiazepine carrying methyl, phenyl and chloro substituents at positions 1, 6 and 8 respectively. Alprazolam is only found in individuals that have taken this drug.


phytochromobilin

A member of the class of bilins which functions as the chromophore of light-sensing phytochromes in plants.


alstonine

An indole alkaloid with formula C21H20N2O3, isolated from several Rauvolfia species and exhibits antipsychotic activity.


phytosterols

Sterols similar to cholesterol which occur in plants and vary only in carbon side chains and/or presence or absence of a double bond.


pinane monoterpenoid

A monoterpenoid based on a pinane skeleton (2,6,6-trimethylbicyclo[3.1.1]heptane) skeleton and its substituted derivatives.


pinocarveol

A  pinane monoterpenoid that is a bicyclo[3.1.1]heptane substituted by two methyl groups at position 6, a methylidene group at position 2 and a hydroxy group at position 3.


piperidinemonocarboxylic acid

Any member of the class of piperidines in which one of the carbons of the piperidine ring is substituted by a carboxy group.


plant growth regulator

A chemical, natural or artificial, that can affect the rate of growth of a plant.


polar amino acid

Any amino acid whose side chain is capable of forming one or more hydrogen bonds.


amabiline

A carboxylic ester obtained by formal condensation of the carboxy group of (2S,3S)-2,3-dihydroxy-2-isopropylbutanoic acid with the hydroxy group of (7aS)-2,3,5,7a-tetrahydropyrrolizin-7-ylmethanol.


poly(N-acetyllactosamine)

An aminoglycan composed of a backbone of N-acetyllactosamine repeating units that are joined to each other via beta-(1->3)-linkages.


polyene antibiotic

A family of antibiotics containing a conjugated polyene moiety, usuallly isolated from some species of Streptomyces.


polyester macromolecule

A macromolecule composed of units connected by carboxylic ester (-O-CO-) linkages.


amantadine

A member of the class of  adamantanes that is used as an antiviral and  antiparkinson drug.


polyketide

Natural and synthetic compounds containing alternating carbonyl and methylene groups ('beta-polyketones'), biogenetically derived from repeated condensation of acetyl coenzyme A (via malonyl coenzyme A), and usually the compounds derived from them by further condensations, etc. Considered by many to be synonymous with the less frequently used terms acetogenins and ketides.


polyol

A compound that contains two or more hydroxy groups.


polyoxin

A group of peptide-pyrimidine nucleoside antibiotics produced by Streptomyces cacaoi var asoensis.


polyphenol

Members of the class of phenols that contain 2 or more benzene rings each of which is substituted by at least one hydroxy group.


polyphosphates

Any phosphate that is a salt or an ester of polyphosphoric acid or its chalcogen analogues.


polyprenol

Any member of the class of  prenols possessing the general formula H-[CH2C(Me)=CHCH2]nOH in which the carbon skeleton is composed of more than one isoprene units.


amaralin

An  azulenofuran that is decahydrooxireno[1,2]azuleno[6,5-b]furan-5(1aH)-one substituted by a hydroxy group at position 8, methyl groups at positions 2 and 7a and a methylidene group at position 6.


polysialic acid

Polymers of sialic acid and derivatives. The degree of polymerization is 8 to 200 Sia residues.


polyterpenoid

A polymeric terpenoid having a C5n skeleton, where n is greater than 8.


polyunsaturated fatty acid

Any fatty acid containing more than one double bond. Acids in this group are reported to have cardioprotective effects; and levels are lowered in chronic fatigue syndrome.


amaranthin

A disaccharide derivative that is betanidin in which a beta-D-glucuronosyl-(1->2)-beta-D-glucosyl moiety is attached at position 5.


porphyrins

Natural pigments containing a fundamental skeleton of four pyrrole nuclei united through the alpha-positions by four methine groups to form a macrocyclic structure.


potassium salt

Any alkali metal salt having potassium(1+) as the cation.


amarogentin

A secoiridoid glycoside that consists of (4aS,5R,6R)-5-ethenyl-6-hydroxy-4,4a,5,6-tetrahydro-1H,3H-pyrano[3,4-c]pyran-1-one having a  2-O-[(3,3',5-trihydroxybiphenyl-2-yl)carbonyl]-beta-D-glucopyranosyl group attached at position 6 via a glycosidic linkage.


precorrin

Any of the intermediates in the biosynthesis of vitamin B12 from uroporphyrinogen III that lie on the pathway before the formation of the first corrin macrocycle. The figure after 'precorrin' corresponds to the number of C-methyl groups introduced into the tetrapyrrole framework.


amaryllisine

An isoquinoline alkaloid that is 3,4,4a,5,6,10b-hexahydro-5,10b-ethanophenanthridin-9-ol bearing three additional methoxy substituents at positions 3, 7 and 8.


4-NITROBENZOIC ACID

A nitrobenzoic acid having the nitro group at the 4-position.


AMASTATIN

A tetrapeptide comprising (2S,3R)-3-amino-2-hydroxy-5-methylhexanoyl, L-valyl, L-valyl and L-aspartic acid units joined in sequence


prenols

Any alcohol possessing the general formula H-[CH2C(Me)=CHCH2]nOH in which the carbon skeleton is composed of one or more isoprene units (biogenetic precursors of the isoprenoids).


amataine

A polycyclic indole alkaloid that is obtained from the root bark of Voacanga africana.


polyprenylhydroquinone

A hydroquinone compound having a polyprenyl substituent in an unspecified position.


prenylnaphthoquinone

Any napthoquinone that is substituted at position 2 by a prenyl or polyprenyl group. The term also includes compounds that are functionalised on the prenyl or polyprenyl chain (e.g. by a hydroxy group).


prenylquinone

A quinone substituted by a polyprenyl-derived side-chain. Prenylquinones occur in all living cells. Due to their amphiphilic character, they are mainly located in biological membranes where they function as electron and proton carriers in the photosynthetic and respiratory electron transport chains. Some prenylquinones also perform more specialised roles sucy as antioxidants and enzyme cofactors. Prenylquinones are classified according to ring structure: the main classes are menaquinones, phylloquinones, ubiquinones and plastoquinones.


proanthocyanidin

A flavonoid oligomer obtained by the the condensation of two or more units of hydroxyflavans.


ambenonium

A symmetrical oxalamide-based bis-quaternary ammonium ion having ethyl and 2-chlorobenzyl groups attached to the nitrogens.


PROLINE

An alpha-amino acid that is pyrrolidine bearing a carboxy substituent at position 2.


proline derivative

An amino acid derivative resulting from reaction of proline at the amino group or the carboxy group, or from the replacement of any hydrogen of proline by a heteroatom. The definition normally excludes peptides containing proline residues.


PROMETRYN

A diamino-1,3,5-triazine that is N,N'-di(propan-2-yl)-1,3,5-triazine-2,4-diamine substituted by a methylsulfanediyl group at position 6.


A primary alcohol based on a propan-1-olskeleton and its substituted derivatives.


propanals

An aldehyde based on a propanal skeleton and its derivatives.


Any  propanediol bearing hydroxy groups at positions 1 and 3.


propanones

A ketone that is propane carrying at least one oxo substituent.


propanoyl-CoAs

Any short-chain fatty acyl-CoA  in which the the fatty acid specified is propanoic acid or its derivatives.


hydramethylnon

A member of the class of hydrazones that is used as an insecticide for control of ants and cockroaches.


PROPIONITRILE

A nitrile that is acrylonitrile in which the carbon-carbon double bond has been reduced to a single bond.


AMENTOFLAVONE

A biflavonoid that is obtained by oxidative coupling of two molecules of apigenin resulting in a bond between positions C-3 of the hydroxyphenyl ring and C-8 of the chromene ring.  A natural product found  particularly in Ginkgo biloba and Hypericum perforatum.


prostaglandin

Naturally occurring compounds derived from the parent C20 acid, prostanoic acid.


amidine

Derivatives of oxoacids RnE(=O)OH in which the hydroxy group is replaced by an amino group and the oxo group is replaced by =NR. In organic chemistry an unspecified amidine is commonly a carboxamidine.


prostanoid

The family of natural prostaglandins and prostaglandin-like compounds including prostacyclins and thromboxanes.


amifostine

An organic thiophosphate that is the S-phospho derivative of 2-[(3-aminopropyl)amino]ethanethiol. A prodrug for the free thiol, WR-1065, which is used as a cytoprotectant in cancer chemotherapy and radiotherapy.


psoralens

A furanocoumarin with a 7H-furo[3,2-g]chromen-7-one skeleton and its substituted derivatives thereof.


amikacin

An amino cyclitol glycoside that is kanamycin A acylated at the N-1 position by a 4-amino-2-hydroxybutyryl group.


pterocarpans

Members of the class of benzofurochromene with a 6a,11a-dihydro-6H-[1]benzofuro[3,2-c]chromene skeleton and its substituted derivatives. They generally bear structural resemblance to isoflavanoids that possess antibiotic activity and are produced by plant tissues in response to infection. They are the 3,4-dihydroderivatives of coumestans.


A p-menthane monoterpenoid that is cyclohexan-1-one substituted by a methyl group at position 5 and a propan-2-ylidene group at position 2.


purine nucleobase

A nucleobase whose skeleton is derived from purine.


amiloride

A member of the class of pyrazines resulting from the formal monoacylation of guanidine with the carboxy group of 3,5-diamino-6-chloropyrazine-2-carboxylic acid.


purine nucleotide

Any nucleotide that has a purine nucleobase.


purine ribonucleoside

A ribonucleoside that has a purine moiety as the nucleobase (the R group in the illustration).


purine ribonucleotide

Any ribonucleotide that has a purine nucleobase.


purines

A class of imidazopyrimidines that consists of purine and its substituted derivatives.


pyridinemonocarboxylic acid

A monocarboxylic acid in which the carboxy group is attached to a pyridine (or substituted pyridine) ring.


pyridines

Any organonitrogen heterocyclic compound based on a pyridine skeleton and its substituted derivatives.


pyrimidine nucleobase

A nucleobase whose skeleton is derived from pyrimidine.


pyrrolecarboxylate

A monocarboxylic acid anion comprising any pyrrole carrying a single carboxylate substiuent.


pyrrolecarboxylic acid

Any pyrrole carrying a single carboxylic acid group.


A monocarboxylic acid anion resulting from the removal of the proton from the carboxy group of any 1-pyrrolinecarboxylic acid.


pyruvate family amino acid

An L-alpha-amino acid which is biosynthesised from pyruvate (i.e. alanine, valine, and leucine). A closed class.


quaternary nitrogen compound

A nitrogen molecular entity that is electronically neutral but which contains a quaternary nitrogen.


quinate

A cyclitol carboxylic acid anion that is conjugate base of quinic acid.


quinic acid

A cyclitol carboxylic acid.


dihydroxyquinoline

Any hydroxyquinoline in which the number of hydroxy substituents is specified as two.


alpha-aminoacyl-tRNA

Any ribonucleic acid that is transfer RNA in which one or more of the free OH groups carries an alpha-aminoacyl group.


quinolinemonocarboxylic acid

Any aromatic carboxylic acid that contains a quinoline moiety that is substituted by one carboxy substituent.


quinolines

A class of aromatic heterocyclic compounds each of which contains a benzene ring ortho fused to carbons 2 and 3 of a pyridine ring.


quinolizidines

An organic heterobicyclic compound that is the octahydro derivative of 2H-quinolizine. The parent of the class of quinolizidines.


radical

A molecular entity possessing an unpaired electron.


reactive oxygen species

Molecules or ions formed by the incomplete one-electron reduction of oxygen. They contribute to the microbicidal activity of phagocytes, regulation of signal transduction and gene expression, and the oxidative damage to biopolymers.


AMINOCARB

A carbamate ester that is phenyl methylcarbamate substituted by a dimethylamino group at position 4 and a methyl group at position 3.


retinoic acid

A retinoid consisting of 3,7-dimethylnona-2,4,6,8-tetraenoic acid substituted at position 9 by a 2,6,6-trimethylcyclohex-1-en-1-yl group (geometry of the four exocyclic double bonds is not specified).


retinoid

Oxygenated derivatives of 3,7-dimethyl-1-(2,6,6-trimethylcyclohex-1-enyl)nona-1,3,5,7-tetraene and derivatives thereof.


aminoglutethimide

A dicarboximide that is a six-membered cyclic compound having ethyl and 4-aminophenyl substituents at the 3-position.


all-trans-retinyl group

A prenyl group obtained by removal of the hydroxy group from all-trans-retinol.


rhamnose

A deoxymannose sugar that is the 6-deoxy derivative of hexose.


ribosyl groups

A glycosyl group obtained by removing the hydroxy group from the hemiacetal function of a ribose and, by extension, of a lower oligosaccharide having ribose at the reducing end.


ribulose 1-phosphate

Any ribulose phosphate in which the phosphate is located at position 1.


rifamycin SV

A member of the class of rifamycins that exhibits antibiotic and antitubercular properties.


Any compound with a 1,3,5-triazine skeleton, in which nitrogen atoms replace carbon at positions 1, 3 and 5 of the core benzene ring structure.


salicylates

Any salt or ester arising from reaction of the carboxy group of salicylic acid, or any ester resulting from the condensation of the phenolic hydroxy group of salicylic acid with an organic acid.


A primary amino compound consisting of ethylamine having a 4-methoxyphenyl substituent at the 2-position.


saponin

A glycoside that is a compound containing one or more hydrophilic glycoside moieties combined with a lipophilic triterpenoid or steroid derivative. Found in particular abundance in plant species.


sapogenin

Any organic polycyclic compound that is the aglycon moiety of a saponin; sapogenins may be steroids or triterpenoids.


saturated fatty acid

Any fatty acid containing no carbon to carbon multiple bonds. Known to produce adverse biological effects when ingested to excess.


selenites

Salts and esters of selenous acid.


amiodarone

A member of the class of 1-benzofurans that is 1-benzofuran substituted by a butyl group at position 2 and a 4-[2-(diethylamino)ethoxy]-3,5-diiodobenzoyl group at position 3. It is a  cardiovascular drug used for the treatment of cardiac dysrhythmias.


selenocystathionine

A member of the class of cystathionines derived from homoselenocysteine and serine residues joined by a selenide bond.


selenodiglutathione

A thioselenide in which a selenium atom is attached to the sulfur atoms of two molecules of glutathione. It is an initial metabolite of selenite, SeO3(2-).


aldehydic acid

A monocarboxylic acid derived from any dicarboxylic acid that has a retained name by the formal reduction of one of the carboxy groups to a formyl group. The resulting structure, also known as a semialdehyde, may be named by replacing the ending '...ic acid' of the retained name of the dicarboxylic acid by the ending '...aldehydic acid'. Aldehydic acids therefore contain one carboxy group and one aldehyde group.


serine derivative

An amino acid derivative resulting from reaction of serine at the amino group or the carboxy group, or from the replacement of any hydrogen of serine by a heteroatom. The definition normally excludes peptides containing serine residues.


amitraz

A tertiary amino compound that is 1,3,5-triazapenta-1,4-diene substituted by a methyl group at position 3 and 2,4-dimethylphenyl groups at positions 1 and 5.


serine family amino acid

An L-alpha-amino acid which is biosynthesised from 3-phosphoglycerate (i.e. serine, glycine, cysteine and homocysteine). A closed class.


sesquiterpenoid

Any terpenoid derived from a sesquiterpene. The term includes compounds in which the C15 skeleton of the parent sesquiterpene has been rearranged or modified by the removal of one or more skeletal atoms (generally methyl groups).


amitriptyline

An organic tricyclic compound that is 10,11-dihydro-5H-dibenzo[a,d][7]annulene substituted by a 3-(dimethylamino)propylidene group at position 5.


sesterterpenoid

Any terpenoid derived from a sesterterpene. The term includes compounds in which the C25 skeleton of the parent sesterterpene has been rearranged or modified by the removal of one or more skeletal atoms (generally methyl groups). Sometimes sesterterpenoids are erroneously referred to as sesterpenoids.


short-chain fatty acid

An aliphatic monocarboxylic acid with a chain length of less than C6. If any non-hydrocarbon substituent is present, the compound is not normally regarded as a short-chain fatty acid.


sialic acid

Any of the N-acylneuraminic acids and their esters and other derivatives of the alcoholic hydroxy groups.


sialosyl group

A glycosyl group derived by removal of the exomeric hydroxy group from any of the sialic acids.


sialoyl group

The acyl group derived from any of the sialic acids by removal of the hydroxy group from its carboxy group.


siderophore

Any of low-molecular-mass iron(III)-chelating compounds produced by microorganisms for the purpose of the transport and sequestration of iron.


amlodipine

A fully substituted dialkyl 1,4-dihydropyridine-3,5-dicarboxylate derivative, which is used for the treatment of hypertension, chronic stable angina and confirmed or suspected vasospastic angina.


singlet dioxygen

A reactive oxygen species that is the lowest excited state of the dioxygen molecule.


ammodendrine

A piperidine alkaloid that is piperidine substituted by a 1-acetyl-1,4,5,6-tetrahydropyridin-3-yl group at position 2 (the 2R-stereoisomer).


sodium salt

Any alkali metal salt having sodium(1+) as the cation.


SOLANESOL

A nonaprenol that is hexatriaconta-2,6,10,14,18,22,26,30,34-nonaen-1-ol substituted by 9 methyl groups at positions 3, 7, 11, 15, 19, 23, 27, 31 and 35 (the all-trans0stereoisomer).


amobarbital

A member of the class of  barbiturates that is pyrimidine-2,4,6(1H,3H,5H)-trione substituted by a 3-methylbutyl and an ethyl group at position 5. Amobarbital has been shown to exhibit sedative and hypnotic properties.


sphingenine

A 2-aminooctadecene-1,3-diol having (2S,3R)-configuration.


sphingolipid

Sphingolipids are a complex family of compounds that share a common structural feature, a sphingoid base backbone.


amodiaquine

A quinoline having a chloro group at the 7-position and an aryl amino group at the 4-position.


A sphingenine in which the C=C double bond is located at the 4-position.


squalene triterpenoid

A triterpenoid based on a  squalene skeleton and its substituted derivatives thereof.


amoxapine

A dibenzooxazepine compound having a chloro substituent at the 2-position and a piperazin-1-yl group at the 11-position.


sterculynic acid

A long-chain, polyunsaturated fatty acid composed of 9-octadecenoic acid having a terminal alkyne group and a 9,10-cyclopropenyl group.


amoxicillin

A penicillin in which the substituent at position 6 of the penam ring is a 2-amino-2-(4-hydroxyphenyl)acetamido group.


steroid hormone

Any steroid that acts as hormone.


stilbenoid

Any olefinic compound characterised by a 1,2-diphenylethylene backbone.


streptothricin

An N-glycosyl compound consisting of 2-amino-4-O-carbamoyl-2-deoxy-N-[(3aS,7R,7aS)-7-hydroxy-4-oxooctahydro-2H-imidazo[4,5-c]pyridin-2-ylidene]-beta-D-gulopyranosylamine in which the amino group at position 2 of the gulopyranosyl moiety is acylated by a peptide unit made up of between 1 and 7 N(epsilon)-linked units of beta-lysine.


succinate

A dicarboxylic acid anion obtained by deprotonation of at least one of the carboxy groups of succinic acid.


sulfuric ester

An ester of an alcohol and sulfuric acid.


amphotericin B

A macrolide antibiotic used to treat potentially life-threatening fungal infections.


sulfates

Salts and esters of sulfuric acid


sulfide

Any sulfur molecular entity that involves either covalently bonded or anionic sulfur.


sulfites

Any sulfurous acid derivative that is a salt or an ester of sulfurous acid.


sulfolipid I

The principal sulfolipid class of virulent human Mycobacterium tuberculosis strain H(37)Rv.


sulfoglycolipid

A sulfate ester of a glycolipid.


SULFURIC ACID

A sulfur oxoacid that consists of two oxo and two hydroxy groups joined covalently to a central sulfur atom.


tannin

Any of a group of astringent polyphenolic vegetable principles or compounds, chiefly complex glucosides of catechol and pyrogallol.


inamrinone

A 3,4'-bipyridine substituted at positions 5 and 6 by an amino group and a keto function respectively. A pyridine phosphodiesterase 3 inhibitor, it is a drug that may improve the prognosis in patients with congestive heart failure.


technetium dioxide

A metal oxide with formula TcO2.


amsacrine

A sulfonamide that is N-phenylmethanesulfonamide substituted by a methoxy group at position 3 and an acridin-9-ylamino group at position 4. It exhibits  antineoplastic activity.


terpene ketone

Any terpenoid which contains a keto group.


terpenoid

Any isoprenoid that is a natural product or related compound formally derived from isoprene units. Terpenoids may contain oxygen in various functional groups. This class is subdivided according to the number of carbon atoms in the parent terpene. The skeleton of terpenoids may differ from strict additivity of isoprene units by the loss or shift of a fragment, generally a methyl group.


terpineol

A family of monoterpenols that have a p-menthane skeleton containing one double bond and bearing a single hydroxy substituent.


tertiary alcohol

A tertiary alcohol is a compound in which a hydroxy group, -OH, is attached to a saturated carbon atom which has three other carbon atoms attached to it.


tetrachlorobenzene

Any member of the class of chlorobenzenes carrying four chloro groups at unspecified positions.


tetrachlorocatechol

A chlorocatechol that is catechol in which all of the hydrogens attached to the benzene ring are replaced by chlorines.


tetracyclic triterpenoid

Any triterpenoid consisting of a tetracyclic skeleton.


tetracyclines

A subclass of polyketides having an octahydrotetracene-2-carboxamide skeleton, substituted with many hydroxy and other groups.


tetradecenoyl-CoA

An unsaturated fatty acyl-CoA that results from the formal condensation of the thiol group of coenzyme A with the carboxy group of a tetradecenoic acid.


tetrahydrofolic acid

A group of heterocyclic compounds based on the 5,6,7,8-tetrahydropteroic acid skeleton conjugated with one or more L-glutamic acid units.


isoamyl nitrite

A nitrite ester having isopentyl as the alkyl group.


TETRAHYDROFURAN

A cyclic ether that is butane in which one hydrogen from each methyl group is substituted by an oxygen.


oxolanes

Any oxacycle having an oxolane (tetrahydrofuran) skeleton.


name: tetrahydronicotinamide adenine dinucleotide phosphate

description: A nicotinamide dinucleotide having any tetrahydronicotinamide and adenosine as the nucleobases as well as an additional phosphate group.


naphthalenetetrol

A hydroxynaphthalene carrying four hydroxy substituents.


tetrapyrrole

A natural pigment containing four pyrrole rings joined by one-carbon units linking position 2 of one pyrrole ring to position 5 of the next.


tetraterpenoid

Any terpenoid derived from a tetraterpene. The term includes compounds in which the C40 skeleton of the parent tetraterpene has been rearranged or modified by the removal of one or more skeletal atoms (generally methyl groups).


tetrose

A four-carbon monosaccharide which in its linear form contains either an aldehyde group at position 1 (aldotetrose) or a ketone group at position 2 (ketotetrose).


thiocyanates

Esters of thiocyanic acid with general formula RSC#N.


abamine

An amino acid ester that is methyl glycine in which one of hydrogens attached to the nitrogen is remplaced by a 4-fluorobenzyl group while the other is replaced by a 3,4-dimethoxycinnamyl group.


thiocarboxylic ester

An ester in which one or both oxygens of an ester group have been replaced by divalent sulfur.


ANACARDIC ACID

A hydroxybenzoic acid that is salicylic acid substituted by a pentadecyl group at position 6. It is a major component of cashew nut shell liquid and exhibits an extensive range of bioactivities.


THIOPHENE

Compounds containing at least one thiophene ring.


thioribose

Any ribose derivative in which at least one of the oxygen atoms of the ribose moiety has been replaced by sulfur.


thiosulfate

An ester of thiosulfuric acid.


organic heterotricyclic compound

An organic tricyclic compound in which at least one of the rings of the tricyclic skeleton contains one or more heteroatoms.


threonine derivative

An amino acid derivative resulting from reaction of threonine at the amino group or the carboxy group, or from the replacement of any hydrogen of threonine by a heteroatom. The definition normally excludes peptides containing threonine residues.


thromboxane

A class of oxygenated oxane derivatives, originally derived from prostaglandin precursors in platelets, that stimulate aggregation of platelets and constriction of blood vessels.


anandamide

An N-acylethanolamine 20:4 resulting from the formal condensation of carboxy group of arachidonic acid with the amino group of ethanolamine.


thymidyl group

A thymidyl group is a group formed by loss of a 3'- or 5'-hydroxy group from the deoxyribose moiety of thymidine.


desmethyl tocotrienol

A tocotrienol that is chroman-6-ol substituted by a methyl group at position 2 and a farnesyl group at position 2.


tolualdehyde

A benzaldehyde compound having a methyl group in an unspecified position.


An  arenesulfonate oxoanion that is the conjugate base of toluene-4-sulfonic acid.


toluenes

Any member of the class of benzenes that is a substituted benzene in which the substituents include one (and only one) methyl group.


toxin

Poisonous substance produced by a biological organism such as a microbe, animal or plant.


cis,trans-muconate

A muconate that is the dianion obtained by the deprotonation of both the carboxy groups of cis,trans-muconic acid.


trans,trans-muconate

A muconate that is the dianion obtained by the deprotonation of both the carboxy groups of trans,trans-muconic acid.


trans,trans-muconic acid

The trans,trans-isomer of muconic acid. It is metabolite of benzene in humans and serves as a biomarker of occupational exposure to benzene.


anastrozole

A 1,2,4-triazole compound having a 3,5-bis(2-cyano-2-propyl)benzyl group at the 1-position.


A dicarboxylic acid dianion resulting from removal of a proton from both carboxy groups of trans-2-carboxybenzylidenepyruvic acid.


A L-proline derivative that is L-proline substituted by hydroxy groups at positions 3 and 4 (the 3S,4S diastereoisomer).


A hexadienal that is hexa-2,5-dienal substituted by a an isopropyl group at position 5 and a methy group at position 2 (the 2E-stereoisomer).


A 2,6-dimethyl-5-methylenehept-2-enoic acid having E-configuration.


A 4-(3-hydroxy-1-benzothiophen-2-yl)-2-oxobut-3-enoate in which the acyclic double bond has E-geometry.


transition element atom

An element whose atom has an incomplete d sub-shell, or which can give rise to cations with an incomplete d sub-shell.


trehalose

A disaccharide formed by a (1<->1)-glycosidic bond between two units of D-glucose.


triaziquone

A member of the class of 1,4-benzoquinones that is 1,4-benzoquinone in which three of the ring hydrogens are replaced by aziridin-1-yl groups.


tricarboxylic acid

An oxoacid containing three carboxy groups.


trichlorobenzene

Any member of the class of chlorobenzenes carrying three chloro substituents at unspecified positions.


trichlorocatechol

A chlorocatechol that is catechol in which three of the remaining four positions on the benzene ring have been substituted by chlorines.


androstenediol

A 3beta-hydroxy-Delta(5)-steroid that is 3beta-hydroxyandrost-5-ene carrying an additional hydroxy group at position 17beta.


trichlorophenol

Any one of the six possible isomers of trichlorophenol.


tridecadienoic acid

A C13 carboxylic acid having two double bonds at unspecified positions in the chain.


trihydroxyflavone

Any  hydroxyflavone carrying three hydroxy groups at unspecified positions.


naphthalenetriol

A hydroxynaphthalene substituted by at least three hydroxy groups.


trihydroxytoluene

Any hydroxytoluene that has three hydroxy substituents.


trimethoxyflavone

A methoxyflavone that is flavone substituted by three methoxy groups.


trimethylarsine

An arsine that is arsane in which each of the hydrogens is substituted by a methyl group.


triol

A chemical compound containing three hydroxy groups.


triose

A monosaccharide containing three carbon atoms, which is important in respiration. Only two trioses occur naturally: the aldotriose glyceraldehyde and the ketotriose dihydroxyacetone.


name: tris-L-cysteinyl L-N1'-histidino tetrairon tetrasulfide


name: tris-L-cysteinyl L-N3'-histidino tetrairon tetrasulfide


name: tris-L-cysteinyl L-aspartato tetrairon tetrasulfide


deanol

A  tertiary amine that is ethanolamine having two N-methyl substituents.


name: tris-L-cysteinyl L-cysteine persulfido L-glutamato L-histidino L-serinyl nickel triiron disulfide trioxide


name: tris-L-cysteinyl L-cysteine persulfido bis-L-glutamato L-histidino nickel triiron disulfide trioxide


name: tris-L-cysteinyl L-cysteine persulfido bis-L-glutamato L-histidino tetrairon disulfide trioxide


name: tris-L-cysteinyl L-serinyl tetrairon tetrasulfide


anethole

A monomethoxybenzene that is methoxybenzene substituted by a prop-1-en-1-yl group at position 4.


Tryptamine and its substitution derivatives.


tryptophan derivative

An amino acid derivative resulting from reaction of tryptophan  at the amino group or the carboxy group, or from the replacement of any hydrogen of tryptophan  by a heteroatom. The definition normally excludes peptides containing tryptophan residues.


ethyltrimethylammonium

A quarternary ammonium cation having one ethyl and three methyl substituents around the central nitrogen.


typhasterol

A brassinosteroid that is ergostan-6-one bearing three additional hydroxy substituents at positions 3alpha, 22R and 23R.


tyramines

Aralkylamino compounds which contain a tyramine skeleton.


L-tyrosine derivative

A proteinogenic amino acid derivative resulting from reaction of L-tyrosine at the amino group or the carboxy group, or from the replacement of any hydrogen of L-tyrosine by a heteroatom.


angiotensin I

A ten amino acid peptide formed by renin cleavage of angiotensinogen. Angiotensin I has no direct biological function except that high levels can stimulate catecholamine production. It is metabolized to its biologically active byproduct angiotensin II, a potent vasoconstrictor, by angiotensin converting enzyme (ACE) through cleavage of the two terminal amino acids.


angiotensin II

An angiotensin II that acts on the central nervous system (PDB entry: 1N9V).


undecaprenols

Polyprenols comprising eleven prenyl units with a terminal hydroxy group.


univalent carboacyl group

A univalent carboacyl group is a group formed by loss of OH from the carboxy group of a carboxylic acid.


unsaturated fatty acid

Any fatty acid containing at least one C=C or C#C bond.


uric acid

An oxopurine that is the final oxidation product of purine metabolism.


uridin-5-yloxyacetic acid

A derivative of uridine, bearing an additional carboxymethoxy substituent at position 5 on the uracil ring.


methyl uridin-5-yloxyacetate

A methyl ester that is uridine which is substituted at position 5 on the uracil ring by a methoxycarbonylmethoxy group.


uridyl group

A uridyl group is a group formed by loss of a 2'-, 3'- or 5'-hydroxy group from the ribose moiety of uridine.


urocanate

An monocarboxylic acid anion that is the conjugate base of urocanic acid.


urocanic acid

An alpha,beta-unsaturated monocarboxylic acid that is prop-2-enoic acid substituted by a 1H-imidazol-4-yl group at position 3. It is a metabolite of hidtidine.


uronic acid

A carbohydrate acid formally derived by oxidation to a carboxy group of the terminal -CH2OH group of any aldose or ketose.


valine

A branched-chain amino acid that consists of glycine in which one of the hydrogens attached to the alpha-carbon is substituted by an isopropyl group.


valine derivative

An amino acid derivative resulting from reaction of valine at the amino group or the carboxy group, or from the replacement of any hydrogen of valine  by a heteroatom. The definition normally excludes peptides containing valine  residues.


very long-chain fatty acid

A fatty acid which has a chain length greater than C22. Very long-chain fatty acids which have a chain length greater than C27 are also known as ultra-long-chain fatty acids.


vinca alkaloid

A group of indole-indoline dimers which are alkaloids obtained from the Vinca genus of plants, together with semi-synthetic and fully synthetic analogues.


violaxanthin

An epoxycarotenol that is 5,5',6,6'-tetrahydro-5,6:5',6'-diepoxy-beta,beta-carotene substituted by hydroxy groups at positions 3 and 3'. It is the naturally occurring xanthophyll pigment found in a variety of plants.


colecalciferol

Any member of a group of fat-soluble hydroxy seco-steroids that exhibit biological activity against vitamin D deficiency. Vitamin D  can be obtained from sun exposure, food and supplements and is biologically inactive and converted into the biologically active calcitriol via double hydroxylation in the body.


xanthophyll

A subclass of carotenoids consisting of the oxygenated carotenes.


xylulose 5-phosphate

A xylulose phosphate in which the phosphate group is at position 5. It is an intermediate metabolite in the pentose phosphate pathway.


name: O-hydroxy(phenyl)phosphinoyl ecgonine methyl ester

description: The O-hydroxy(phenyl)phosphinoyl derivative of ecgonine methyl ester.


zwitterion

A neutral compound having formal unit electrical charges of opposite sign on non-adjacent atoms. Sometimes referred to as inner salts, dipolar ions (a misnomer).


D-chiro-inositol

Belonging to the inositol family of compounds, D-chiro-inositol (DCI) is an isomer of glucose. It is an important secondary messenger in insulin signal transduction.


dexpanthenol

A monocarboxylic acid amide that is 3,3-dimethylbutanamide substituted by hydroxy groups at positions 2 and 4 and a 3-hydroxypropyl group at the carbomyl nitrogen.


methanesulfonic acid

An alkanesulfonic acid in which the alkyl group directly linked to the sulfo functionality is methyl.


Any aldose having 2S,3R-threo stereochemistry. A representative structure is provided.


A cholestanoyl-CoA formed by thioester linkage between  3alpha,7alpha,12alpha-trihydroxy-24-oxo-5beta-cholestan-26-oic acid and coenzyme A.


2,2',3-trihydroxydiphenyl ether

Diphenyl ether in which the hydrogens at the 2, 3, and 2' positions are substituted by hydroxy groups.


A nitrile that is acetonitrile where one of the methyl hydrogens is substituted by a 2-thienyl group.


An imidazol-4-one having a 2-carboxyethyl substituent at the 5-position.


carbon tetrachloride

A chlorocarbon that is methane in which all the hydrogens have been replaced by chloro groups.


cinnamic acid

A monocarboxylic acid that consists of acrylic acid bearing a phenyl substituent at the 3-position. It is found in Cinnamomum cassia.


A trisaccharide consisting of two alpha-D-galactopyranose residues and a D-glucopyranose residue joined in sequence by (1->6) glycosidic bonds.


benzoylacetyl-CoA

An acyl-CoA that results from the formal condensation of the thiol group of coenzyme A with the carboxy group of benzoylacetic acid.


3-aminoisobutyric acid

A beta-amino-acid that is isobutyric acid in which one of the methyl hydrogens is substituted by an amino group.


omega-aminoaldehyde

An amino aldehyde that is an aliphatic aldehyde in which one of the hydrogens of the terminal methyl group has been replaced by an amino group. H2NCH2(CH2)nCHO, where n = 0, 1, 2, etc.


A UDP-amino sugar having 3-O-(3-hydroxytetradecanoyl)-D-glucosamine as the amino sugar component.


A galloyl-beta-D-glucose compound having the galloyl groups in the 1-, 2- and 6-positions.


deisopropylatrazine

A diamino-1,3,5-triazine that is N-ethyl-1,3,5-triazine-2,4-diamine substituted by a chloro group at position 6.


ankorine

A pyridoisoquinoline that is 1,3,4,6,7,11b-hexahydro-2H-pyrido[2,1-a]isoquinoline which is substituted at positions 2, 3, and 8 by 2-hydroxyethyl, ethyl, and hydroxy groups, respectively, and by methoxy groups at positions 9 and 10 (the 2R,3R,11bS stereoisomer). It is a benzo[a]quinolizidine alkaloid isolated from the Indian medicinal plant Alangium lamarckii.


A long-chain (3S)-hydroxy fatty acyl-CoA that results from the formal condensation of the thiol group of coenzyme A with the carboxy group of (S)-3-hydroxypalmitic acid.


A cholestanoyl-CoA formed by thioester linkage between 3alpha,7alpha,24-trihydroxy-5beta-cholestanoic acid and coenzyme A.


streptidine

An amino cyclitol that is scyllo-inositol in which the hydroxy groups at positions 1 and 3 are replaced by guanidino groups.


kinetin

A member of the class of 6-aminopurines that is  adenine carrying a (furan-2-ylmethyl) substituent at the exocyclic amino group.


manniflavanone

A biflavonoid isolated from Garcinia buchananii and has been shown to exhibit antioxidant activity.


A pyridone that is 2-pyridone substituted with a carboxamide group at C-5 and a methyl group at N-1.


beta-aminopropionitrile

An aminopropionitrile carrying an amino group at the beta-position.


P-XYLENE

A xylene with methyl groups at positions 1 and 4.


NAPHTHOQUINONE

The parent structure of the family of 1,4-naphthoquinones, in which the oxo groups of the quinone moiety are at positions 1 and 4 of the naphthalene ring. Derivatives have pharmacological properties.


dehydrodeoxycoformycin

A coformycin that is dehydrocoformycin with the hydroxy group at position 2 replaced with a hydrogen.


A hydroxykynurenamine that is kynurenamine carrying a hydroxy group at position 3. It is a metabolite of tryptophan that exhibits antiinflammatory and immunomodulatory properties.


(KDO)2-(lauroyl)-lipid IVA

A lipid A comprising lipid IVA glycosylated with two 3-deoxy-D-manno-octulosonic acid (KDO) residues and carrying an additional dodecanoyl group.


N-acetyl-alpha-D-glucosaminide

Any N-acetyl-D-glucosaminide having alpha-configuration at the anomeric centre.


A hydroxyisoflavone that is luteone in which the hydroxy group at position 7 is replaced by a methoxy group.


α-linolenic acid

A linolenic acid with cis-double bonds at positions 9, 12 and 15. Shown to have an antithrombotic effect.


gibberellin A53

A C20-gibberellin, initially identified in Vicia faba, that is gibberellin A12 in which a hydroxy substituent is present at the 7alpha- position.


o-tolualdehyde

A tolualdehyde compound with the methyl substituent at the 2-position.


An organic cation that is 1-pyrroline bearing an N-methyl substituent.


methyltestosterone

A 17beta-hydroxy steroid that is testosterone bearing a methyl group at the 17alpha position.


(KDO)-lipid IVA

Lipid IVA glycosylated with a single 3-deoxy-D-manno-octulosonic acid (KDO) residue.


3-methoxyanthranilic acid

An aminobenzoic acid that is anthranilic acid in which the hydrogen at position 3 is substituted by a methoxy group. It is a metabolite of kynurenine.


D-prephenyl lactate

A carboxylic acid having D-lactic acid as the carboxylic acid component and a 3-hydroxycyclohexa-1,4-diene as the alcohol component.


beta-D-fucose

A D-fucopyranose with a beta-configuration at the anomeric position.


A terminal acetylenic compound that is but-1-yne with one of the methyl hydrogens substituted by a hydroxy group.


maltohexaose

A maltohexaose hexasaccharide in which the glucose residue at the reducing end is in the aldehydo open-chain form.


phenoxymethylpenicillin

A penicillin compound having a 6beta-(phenoxyacetyl)amino side-chain.


lutein 5,6-epoxide

An epoxycarotenol derivative of lutein.


N-propanoylimidazole

An N-acylimidazole compound having propanoyl as the acyl group.


DICHLOROPHENOL INDOPHENOL

1,4-benzoquinone imine having a 3,5-dichloro-4-hydroxyphenyl substituent attached to the nitrogen atom.


STYRENE

A vinylarene that is benzene carrying a vinyl group. It has been isolated from the benzoin resin produced by Styrax species.


A chlorophenylethylene that is chloroethene in which the methylene hydrogens are replaced by 4-chlorophenyl groups.


trichloroacetate

A monocarboxylic acid anion that results from the removal of a proton from the carboxylic acid group of trichloroacetic acid.


An undecaprenyldiphospho-N-acetylmuramoyl peptide in which the peptide moiety is L-alanyl-D-isoglutaminyl-N(6)-pentaglycyl-L-lysyl-D-alanyl-D-alanine.


A cholestanoyl-CoA formed by thioester linkage between 3alpha,7alpha,12alpha,24-tetrahydroxy-5beta-cholestan-26-oic acid and coenzyme A.


N-glycoloyl-D-glucosamine

An N-glycoloylglucosamine of D configuration.


selenohomocystine

A diselenide resulting from the dehydrogenation reaction between two units of 2-amino-4-selanylbutanoic acid.


A long-chain (3S)-hydroxy fatty acyl-CoA that results from the formal condensation of the thiol group of coenzyme A with the carboxy group of (S)-3-hydroxytetradecanoic acid.


A pyrimidone obtained by formal addition of hydrogen across the 5,6-position of thymine.


2-dehydro-D-gluconic acid

A ketoaldonic acid that is D-gluconic acid in which the hydroxy group at position 2 has been oxidised to a keto group.


anthemis glycoside A

An anthemis glycoside that is found in the cyanogenic achenes of Anthemis altissima.


folic acid

An N-acyl-amino acid that is a form of the water-soluble vitamin B9. Its biologically active forms (tetrahydrofolate and others) are essential for nucleotide biosynthesis and homocysteine remethylation.


glycodeoxycholic acid

A bile acid glycine conjugate of deoxycholic acid.


cyanidin 3-O-beta-D-galactoside

An anthocyanin cation that is cyanidin(1+) carrying a single beta-D-galactosyl substituent at position 3.


RIBOSE (PYRANOSE)

A D-ribopyranose with a beta-configuration at the anomeric position.


D-valine

The D-enantiomer of valine.


A hydroxyisoflavone that is daidzein bearing an additional hydroxy substituent at position 2'.


PHENACETURIC ACID

A N-acylglycine that is glycine substituted on nitrogen with a phenylacetyl group.


A member of the class of prostaglandins J that consists of prosta-5,9,13-trien-1-oic acid substituted by an oxo group at position 11 and a hydroxy group at position 15 (the 5Z,13E,15S stereoisomer).


A 3beta-hydroxy-Delta(5)-steroid that is pregnenolone with a double bond between positions 16 and 17.


3-(imidazol-5-yl)lactic acid

A 2-hydroxy monocarboxylic acid that is lactic acid in which one of the methyl hydrogens has been replaced by an imidazol-5-yl group.


A  fluorobenzoyl-CoA that results from the formal condensation of the thiol group of coenzyme A with the carboxy group of 2-fluorobenzoic acid.


leukotriene F4

A leukotriene composed of (7E,9E,11Z,14Z)-icosa-7,9,11,14-tetraenoic acid having (5S)-hydroxy and (6R)-(L-gamma-glutamyl-L-cystein-S-yl) substituents.


juvenile hormone III

A member of the juvenile hormone family of compounds that is the methyl ester of (2E,6E)-9-[(2R)-3,3-dimethyloxiran-2-yl]-3,7-dimethylnona-2,6-dienoic acid. Juvenile hormone III is found in most insect species.


sophoraisoflavanone A

A hydroxyisoflavanone that is isoflavanone substituted by hydroxy groups at positions 5, 7 and 4', a methoxy substituent at position 2' and a prenyl group at position 3'.


SIMAZINE

A diamino-1,3,5-triazine that is N,N'-diethyl-1,3,5-triazine-2,4-diamine substituted by a chloro group at position 6.


A dTDP-sugar having 4-dehydro-3-methyl-2,6-dideoxy-beta-L-glucose as the sugar component.


A sialomonoglycosylceramide having N-acetyl-alpha-neuraminosyl-(2->3)-beta-D-galactosyl as the sialomonoglycosyl component.


4-aminobenzenesulfonic acid

An  aminobenzenesulfonic acid that is aniline sulfonated at the para-position.


aldehydo-D-mannosamine

A D-mannosamine in open-chain aldehydo-form.


A steroidal acyl-CoA that results from the formal condensation of the thiol group of coenzyme A with the carboxy group of 3alpha,7alpha,12alpha-trihydroxy-5beta-cholest-24-en-26-oic acid.


neoglucobrassicin

An indolyl carbohydrate that is glucobrassicin methoxy substituted at position 1 of the indole moiety.


cinchonine

Cinchonan in which a hydrogen at position 9 is substituted by hydroxy (S configuration). It occurs in the bark of most varieties of Cinchona shrubs, and is frequently used for directing chirality in asymmetric synthesis.


UMBELLIFERONE

A hydroxycoumarin that is coumarin substituted by a hydroxy group ay position 7.


The intermediate in the biosynthesis of vitamin B12 from uroporphyrinogen III in which six methyl groups have been introduced into the tetrapyrrole framework, together with ring contraction.


A sialotetraosylceramide consisting of a branched octasaccharide made up from four sialyl residues, two galactose residues, one N-acetylglucosamine residue and a glucose residue at the reducing end attached to the ceramide portion via a beta-linkage.


rutinose

A glycosylglucose in which the glycosyl moiety is L-rhamnose linked alpha to C-6 of D-glucose.


The hydroxy monocarboxylic acid anion that is the conjugate base of 3-(6-hydroxyindol-3-yl)lactic acid.


A derivative of aniline in which the hydrogen at position 2 has been substituted by fluorine. It is used as a pharmaceutical intermediate


P(1),P(2)-bis(5'-adenosyl) triphosphate

A diadenosyl triphosphate having the two 5'-adenosyl residues attached at the P(1)- and P(2)-positions.


4-hydroxy-2-oxohexanoic acid

A hydroxy- and oxo- fatty acid comprising hexanoic acid substituted at C-2 and C-4 with oxo and hydroxy groups respectively.


L-cysteine thioether

Any L-cysteine derivative obtained by conversion of the thiol group into a sulfide.


alpha-D-mannoside

Any mannoside in which the anomeric centre has alpha-configuration.


An unsaturated fatty acyl-CoA that results from the formal condensation of the thiol group of coenzyme A with the carboxy group of trans-oct-2-enoic acid.


ISATIN

An indoledione that is the 2,3-diketo derivative of indole.


hexanoyl-CoA

A medium-chain fatty acyl-CoA having hexanoyl as the S-acyl group.


3',5'-cyclic IMP

A 3',5'-cyclic purine nucleotide having hypoxanthine as the nucleobase.


METHYL OLEATE

A fatty acid methyl ester resulting from the formal condensation of the carboxy group of oleic acid with methanol.


A dichlorohydroquinone that is hydroquinone substituted by chloro groups at positions 2 and 5 respectively.


A purine 2'-deoxyribonucleoside having O(6)-methylguanine as the nucleobase.


anthragallol

A trihydroxyanthraquinone that is anthracene-9,10-dione substituted by hydroxy groups at positions 1, 2 and 3.


A pyrimidine that is a derivative of cytosine, having a methyl group at the 5-position.


isosakuranetin

A dihydroxyflavanone that is flavanone substituted by hydroxy groups at positions 5 and 7 and a methoxy group at position 4' (the 2S stereoisomer).


The beta-anomer of alpha-D-glucosyl-(1->3)-D-mannopyranose


prostaglandin C2

A member of the class of prostaglandins C that is prosta-5,11,13-trien-1-oic acid carrying oxo and hydroxy substituents at positions 9 and 15 respectively (the 5Z,13E,15S-stereoisomer).


An  anthracenetriol that is anthracene substituted by hydroxy groups at positions 1, 8 and 9.


OXIRANE

A  saturated organic heteromonocyclic parent that is a three-membered heterocycle of two carbon atoms and one oxygen atom.


20-hydroxy-20-oxoleukotriene B4

A member of the class of leukotrienes that is leukotriene B4 in which the terminal methyl group has undergone formal oxidation to the corresponding carboxylic acid.


A 3-methylguanine that is 3,7-dihydro-6H-purin-6-one substituted by an amino group at position 2 and a methyl group at position 3.


aminosalicylic acid

An aminobenzoic acid that is salicylic acid substituted by an amino group at position 4.


A trihydroxyflavanone having a structure of naringenin prenylated at C-6.


arabinogalactan

A polysaccharide composed of repeating units of arabinosylgalactose.


histidine

An alpha-amino acid that is propanoic acid bearing an amino substituent at position 2 and a 1H-imidazol-4-yl group at position 3.


A keto-disaccharide that is beta-D-galactosyl-(1->4)-beta-D-glucose in which the hydroxy group at position 3 of the galactosyl moiety has been oxidised to the corresponding ketone.


ATPGAMMAS

A nucleoside triphosphate analogue that is ATP in which one of the oxygens attached to 3-phosphate group is replaced by sulfur.


phosphoramidate ester

A phosphoric ester (phosphate) that has an NR2 instead of an OH group.


alpha-amino-gamma-cyanobutanoic acid

An alpha-amino acid that is 2-aminobutanoic acid substituted at position 4 by a cyano group.


5-ureidoimidazole-4-carboxylic acid

An imidazole-4-carboxylic acid compound having a ureido substituent at the 5-position.


The pteridine that is lumazine substituted with a methyl group at C-6, a hydroxy group at C-7 and a 1-D-ribityl group at N-8.


aldosterone

A pregnane-based steroidal hormone produced by the outer-section (zona glomerulosa) of the adrenal cortex in the adrenal gland, and acts on the distal tubules and collecting ducts of the kidney to cause the conservation of sodium, secretion of potassium, increased water retention, and increased blood pressure. The overall effect of aldosterone is to increase reabsorption of ions and water in the kidney.


selenomethionine

A selenoamino acid that is the selenium analogue of methionine.


beta-L-rhamnopyranose

The beta-anomer of L-rhamnopyranose.


GARBANZOL

A member of the class of dihydroflavonols that is (2S)-flavanone substituted by hydroxy groups at positions 3, 7 and 4'.


procyanidin B4

A proanthocyanidin obtained by the condensation of (-)-epicatechin and (+)-catechin units.


7-hydroxyflavanone 7-O-beta-D-glucoside

A flavanone 7-O-beta-D-glucoside that consists of 7-hydroxyflavanone attached to a  beta-D-glucopyranosyl moiety at position 7 via a glycosidic linkage.


ectoine

A carboxamidine heterocycle obtained by formal condensation of (2S)-2,4-diaminobutanoic acid with acetic acid.


A dioxo monocarboxylic acid that is benzene in which the hydrogens at position 1, 2 and 3 are replaced by 3-carboxy-3-oxopropanoyl, amino and hydroxy groups, respectively. It is a by-product of tryptophan metabolism.


CHARCOAL, ACTIVATED

An allotropic form of the element carbon with cubic structure which is thermodynamically stable at pressures above 6 GPa at room temperature and metastable at atmospheric pressure. At low pressures diamond converts rapidly to graphite at temperatures above 1900 K in an inert atmosphere. The chemical bonding between the carbon atoms is covalent with sp(3) hybridization.


11-epi-prostaglandin F2alpha

The prostaglandin F that is the 11-epimer of prostaglandin F2alpha.


N(pros)-methyl-L-histidine

A L-histidine derivative that is L-histidine substituted by a methyl group at position 3 on the imidazole ring.


3-(5-hydroxyindol-3-yl)pyruvic acid

A hydroxyindole that is indole substituted by a 2-carboxy-2-oxoethyl group at position 2 and a hydroxy group at position 5.


ANTIAROL

A member of the class of  phenols that is phenol substituted by methoxy groups at positions 3, 4 and 5.


4-hydroxyphthalic acid

A hydroxybenzoic acid that is phthalic acid in which the hydrogen at position 4 is substituted by a hydroxy group.


name: O-alpha-D-glucosyl poly(glycerol phosphate) macromolecule

description: A poly(glycerol phosphate) macromolecule having alpha-D-glucosyl residues at the secondary hydroxy groups on the repeating units.


A tetrasaccharide consisting of raffinose, to the furanose O-1 position of which is linked an alpha-D-galactosyl group.


D-psicose

The D-enantiomer of psicose.


thymol

A phenol that is a natural monoterpene derivative of cymene.


An acyl-CoA that results from the formal condensation of the thiol group of coenzyme A with the carboxy group of cyclohexa-2,5-diene-1-carboxylic acid.


A naphthylmethanol that is methanol in which one of the methyl hydrogens has been replaced by a (2-naphthyl) group.


PSORALEN

The simplest member of the class of psoralens that is 7H-furo[3,2-g]chromene having a keto group at position 7. It has been found in plants like  Psoralea corylifolia and Ficus salicifolia.


monensin

A spiroketal, monensin A is the major component of monensin, a mixture of antibiotic substances produced by Streptomyces cinnamonensis. An antiprotozoal, it is used as the sodium salt as a feed additive for the prevention of coccidiosis in poultry and as a growth promoter in cattle.


chalcone

A member of the class of chalcones that is acetophenone in which one of the methyl hydrogens has been replaced by a benzylidene group.


ANTIMYCIN A

A nine-membered bis-lactone having methyl substituents at the 2- and 6-positions, an n-hexyl substituent at the 8-position, an acyloxy substituent at the 7-position and an aroylamido substituent at the 3-position. It is produced by Streptomyces bacteria and has found commercial use as a fish poison.


L-arginine ester

Any ester of L-arginine or its derivatives.


vanillylmandelate

A hydroxy monocarboxylic acid anion that is the conjugate base of vanillylmandelic acid.


PROSTAGLANDIN B1

A member of the class of prostaglandins B that is prosta-8(12),13-dien-1-oic acid carrying oxo and hydroxy substituents at positions 9 and 15 respectively (the 13E,15S-stereoisomer).


4-isopropylbenzyl alcohol

A member of the class of benzyl alcohols in which the hydrogen at position 4 on the phenyl ring of benzyl alcohol has been replaced by an isopropyl group.


The intermediate in the biosynthesis of vitamin B12 from uroporphyrinogen III in which five methyl groups have been introduced into the tetrapyrrole framework, together with ring contraction.


An N-acylglycine resulting from the formal condensation of the carboxy group of (5-hydroxyindol-3-yl)acetic acid with the amino group of glycine.


ACETOPHENONE

A methyl ketone that is acetone in which one of the methyl groups has been replaced by a phenyl group.


A dichlorohydroquinone that is hydroquinone substituted by chloro groups at positions 2 and 6.


The epoxy steroid formed from cholest-5-ene by formal addition of oxygen across the 5,6 double bond with alpha-configuration at both C-5 and C-6.


3,4-dihydroxymandelic acid

A catechol that is the 3,4-dihydroxy derivative of mandelic acid; a metabolite of L-dopa.


cobalt atom

A cobalt group element atom that has atomic number 27.


An acyl-CoA that results from the formal condensation of the thiol group of coenzyme A with the carboxy group of (E)-2-benzylidenesuccinic acid.


cycloheximide

A dicarboximide that is 4-(2-hydroxyethyl)piperidine-2,6-dione in which one of the hydrogens attached to the carbon  bearing the hydroxy group is replaced by a 3,5-dimethyl-2-oxocyclohexyl group. It is an antibiotic produced by the bacterium Streptomyces griseus.


methyl tert-butyl ether

An ether having methyl and tert-butyl as the two alkyl components.


A dTDP-sugar having 3-dehydro-4,6-dideoxy-alpha-D-glucose as the sugar component.


An oxo-fatty acyl-CoA that results from the formal condensation of the thiol group of coenzyme A with the carboxylic acid group of 3-oxohexanoic acid.


isomaltotriose

A glucotriose consisting of two alpha-D-glucopyranose residues and a D-glucopyranose residue joined in sequence by (1->6) glycosidic bonds.


CIFOSTODINE

A 2',3'-cyclic pyrimidine nucleotide in which cytidine is the parent nucleoside.


DAVIDIGENIN

A member of the class of dihydrochalcones that is dihydrochalcone substituted by hydroxy groups at positions 4, 2', and 4' respectively.


CAMPTOTHECIN

A pyranoindolizinoquinoline that is pyrano[3',4':6,7]indolizino[1,2-b]quinoline which is substituted by oxo groups at positions 3 and 14, and by an ethyl group and a hydroxy group at position 4 (the S enantiomer).


N-succinyl-L-glutamic 5-semialdehyde

A dicarboxylic acid monoamide obtained by the formal condensation of amino group of L-glutamic 5-semialdehyde with one of the carboxy groups of succinic acid.


2-oxo aldehyde

Any aldehyde having an oxo substituent at the 2-position.


APHIDICOLIN

A tetracyclic diterpenoid that has an tetradecahydro-8,11a-methanocyclohepta[a]naphthalene skeleton with two hydroxymethyl substituents at positions 4 and 9, two methyl substituents at positions 4 and 11b and two hydroxy substituents at positions 3 and 9. An antibiotic with antiviral and antimitotical properties. Aphidicolin is a reversible inhibitor of eukaryotic nuclear DNA replication.


CONVALLATOXIN

A cardenolide glycoside that consists of strophanthidin having a 6-deoxy-alpha-L-mannopyranosyl (L-rhamnosyl) group attached at position 3.


A 3-oxoacyl-CoA having its S-acyl component derived from 2-oxocyclohexane-1-carboxylic acid.


b-D-GALACTOSE

A D-galactopyranose having beta configuration at the anomeric centre.


A hydroxy fatty acyl-CoA that results from the formal condensation of the thiol group of coenzyme A with the carboxy group of (S)-3-hydroxydodecanoic acid.


neoastilbin

A flavanone glycoside that is (-)-taxifolin substituted by a alpha-L-rhamnosyl moiety at position 3 via a glycosidic linkage.


HERBACETIN

A pentahydroxyflavone that is kaempferol substituted by a hydroxy group at position 8. It is a natural flavonoid from flaxseed which exerts antioxidant, anti-inflammatory and anticancer activities.


chlorohydroquinone

A benzenediol that consists of hydroquinone bearing a single chloro substituent.


L-HISTIDINAL

An amino aldehyde obtained by partial reduction of the carboxy group of L-histidine


A  fluorobenzoyl-CoA that results from the formal condensation of the thiol group of coenzyme A with the carboxy group of 4-fluorobenzoic acid.


A dTDP-sugar having 3-dehydro-6-deoxy-alpha-D-glucose as the sugar component.


betagarin

An extended flavonoid that is 6,7-methylenedioxyflavanone substituted by methoxy groups at positions 5 and 2' respectively.


galactomannan

A heteroglycan consisting of a mannan backbone with galactose side groups.


(S)-2-acetyl-2-hydroxybutanoic acid

A 3-oxo monocarboxylic acid that is butanoic acid in which the hydrogens at position 2 are replaced by an acetyl and a hydroxy group (the S enantiomer).


A 2-hydroxy monocarboxylic acid that is acrylic acid in which the hydrogen at position 2 is substituted by a hydroxy group and a hydrogen at position 3 is substituted by a 4-hydroxyphenyl group.


A leucoanthocyanidin that is the 3-deoxy derivative of (2R,3S,4S)-leucocyanidin.


flavonol 3-O-D-xylosyl-D-glucoside

A glycosyloxyflavone that consists of flavonol attached to a D-xylosyl-D-glucosyl residue at position 3 via a glycosidic linkage.


A polyprenylbenzoquinone that is fumigatin which is substituted by an all-trans-octaprenyl group at position 6.


decanoate

A fatty acid anion 10:0 that is the conjugate base of decanoic acid.


APIGENIN DIMETHYLETHER

A dimethoxyflavone  that is the 7,4'-dimethyl ether derivative of apigenin.


A sialotetraosylceramide consisting of a branched heptasaccharide made up from three sialyl residues, two galactose residues, one N-acetylglucosamine residue and a glucose residue at the reducing end attached to the ceramide portion via a beta-linkage.


lipid II

An undecaprenyldiphospho-N-acetyl-(N-acetylglucosaminyl)muramoyl peptide in which the peptide element is L-alanyl-D-gamma-glutamyl-L-lysyl-D-alanyl-D-alanine.


sitosterol

A member of the class of phytosterols that is stigmast-5-ene substituted by a beta-hydroxy group at position 3.


GLUTAURINE

A dipeptide resulting from the formal condensation of the amino group of taurine with the gamma-carboxy group of L-glutamic acid. It was initially found in the parathyroid in 1980 and later in the brain of mammals.


A 3-enoyl-CoA in which the beta C=C double bond has trans stereochemistry.


S-hexylglutathione

An S-substituted glutathione that is glutathione in which the hydrogen of the thiol has been replaced by a hexyl group (PDB entry: 1PN9).


(+)-vernolic acid

An optically active form of vernolic acid having (12S,13R)-configuration.


An amino disaccharide consisting of beta-D-galactose linked via a (1->3)-glycosidic bond to N-acetyl-D-glucosamine.


DIETHYL HYDROGEN PHOSPHATE

A  dialkyl phosphate having ethyl as the alkyl group.


DIETHYL SULFIDE

An ethyl sulfide compound having two ethyl groups attached to a sulfur atom.


The intermediate in the biosynthesis of vitamin B12 from uroporphyrinogen III in which three methyl groups have been introduced at positions 2, 7 and 20 of the tetrapyrrole framework and in which the carboxymethyl group at position 2 has been oxidised to form a lactone ring.


thioetheramide PC

A member of the class of 1-thio-sn-glycero-3-phosphocholines that is (2S)-2-amino-3-sulfanylpropyl 2-(trimethylazaniumyl)ethyl phosphate in which the amino group is substituted by a palmitoyl group and the thiol is substituted by a palmityl group. It is a reversible inhibitor of secretory phospholipase A2.


A member of the class of pyrimidodiazepine 3,7,8,9-tetrahydropyrimido[4,5-b][1,4]diazepin-4-one bearing amino and acetyl substituents at positions 2 and 6 respectively.


A chlorocatechol that is catechol in which the hydrogen adjacent to one of the hydroxy groups is replaced by a chlorine.


gibberellin A1

A C19-gibberellin, initially identified in Gibberella fujikuroi.


A glycooctaosylceramide in which the sugar component is a linear heptasaccharide comprised of fucose, galactose, N-acetylgalactosamine, glucose and N-acetylglucosamine residues, branched with an extra L-fucosyl residue at one of the central galactose residues within the chain.


A GDP-sugar having 4-dehydro-6-deoxy-L-mannose as the sugar component.


BUTIN

A trihydroxyflavanone in which the three hydroxy substituents are located at positions 3', 4' and 7. It is found in Acacia mearnsii, Vernonia anthelmintica and Dalbergia odorifera and has a protective affect against oxidative stress-induced mitochondrial dysfunction.


digitonin

A spirostanyl glycoside that is digitogenin in which the 3-hydroxy group is substituted by a beta-D-glucopyranosyl-(1->3)-beta-D-galactopyranosyl-(1->2)-[beta-D-xylopyranosyl-(1->3)]-beta-D-glucopyranosyl-(1->4)-beta-D-galactopyranosyl group. It is a steroidal saponin isolated from the foxglove plant, Digitalis purpurea. It is used extensively as a mild non-ionic detergent for extracting proteins from membranes for structure and function studies.


D-isoleucine

The D-enantiomer of isoleucine.


A glycotriaosylceramide having N-acetyl-beta-D-galactosyl-(1->4)-beta-D-galactosyl-(1->4)-beta-D-glucosyl as the triaosyl component.


caffeine

A trimethylxanthine in which the three methyl groups are located at positions 1, 3, and 7. A purine alkaloid that occurs naturally in tea and coffee.


gamma-carotene

A cyclic carotene obtained by the cyclisation of lycopene.


Any hydroxyflavone with a hydroxy substituent at position 3'.


gibberellin A20

A C19-gibberellin that is a pentacyclic diterpenoid responsible for promoting growth and development. Initially identified in Gibberella fujikuroi, it differs from gibberellin A1 in lacking an OH group at C-2 (gibbane numbering).


GLYPHOSATE

A phosphonic acid resulting from the formal oxidative coupling of the methyl group of methylphosphonic acid with the amino group of glycine. It is one of the most commonly used herbicides worldwide, and the only one to target the enzyme 5-enolpyruvyl-3-shikimate phosphate synthase (EPSPS).


L-homoarginine

An L-lysine derivative that is the L-enantiomer of homoarginine.


D-ribosylnicotinic acid

A pyridine nucleoside consisting of nicotinic acid with a beta-D-ribofuranosyl moiety at the 1-position.


beta-alanyl-L-lysine

A dipeptide consisting of beta-alanine and L-lysine units joined by a peptide linkage.


ETHYL ACETATE

The acetate ester formed between acetic acid and ethanol.


methacrylyl-CoA

An acyl-CoA that results from the formal condensation of the thiol group of coenzyme A with the carboxy group of methacrylic acid.


A monochlorobiphenyl carrying a chloro substituent at position 4.


3,4-dihydroxybenzenesulfonic acid

A benzene ring substituted with a sulphonic acid group at position C-1, and hydroxy groups at C-3 and C-4.


L-selenocystathionine

An optically active form of selenocystathionine in which both amino acid residues have L-configuration.


The (S)-enantiomer of 3-hydroxy-3-methyl-2-oxopentanoate.


A dimethoxyflavone that is the 3,7-di-O-methyl derivative of quercetagetin.


A monohydroxyacetophenone that is acetophenone substituted by methoxy groups at positions 2' and 6' and a hydroxy group at position 4'.


nonanoyl-CoA

A medium-chain fatty acyl-CoA that results from the formal condensation of the thiol group of coenzyme A with the carboxy group of nonanoic acid.


A chlorocatechol that is catechol substituted by a chloro group at position 4.


A 3-enoyl-CoA in which the beta C=C double bond has cis stereochemistry.


LUBIMIN

A vetispirane sesquiterpenoid that consists of (2R,5S,6S,8S,10R)-8-hydroxy-10-methyl-2-(prop-1-en-2-yl)spiro[4.5]decane bearing a formyl substituent at position 6.


A diadenosyl triphosphate having the two 5'-adenosyl residues attached at the P(1)- and P(3)-positions.


geissospermine

A indole alkaloid comprising two indole-derived polycyclic moieties joined by a cyclic ether linkage.


acetohydroxamic acid

A member of the class of acetohydroxamic acids that is acetamide in which one of the amino hydrogens has been replaced by a hydroxy group.


griseofulvin

An oxaspiro compound produced by Penicillium griseofulvum. It is used by mouth as an antifungal drug for infections involving the scalp, hair, nails and skin that do not respond to topical treatment.


detergent

A surfactant (or a mixture containing one or more surfactants) having cleaning properties in dilute solutions.


MYRISTOLEIC ACID

A tetradecenoic acid in which the double bond is at the 9-10 position and has Z configuration. Myristoleic acid has been isolated from Serenoa repens and has cytotoxic and apoptosis-inducing effects.


A ribonucleotide that is the 3'-dehydro derivative of adenosine 5'-triphosphate.


AMPHOTERICIN B ME ESTER

The methyl ester of amphotericin B.


A member of the class of chloroethanes substituted by two chloro groups at positions 1 and 2.


diquafosol

A pyrimidine ribonucleoside 5'-tetraphosphate compound having 5'-uridinyl residues at the P(1)- and P(4)-positions.


DL-cycloserine

A racemate comprising equimolar amounts of D- and L-cycloserine.


beta-carotene 5,6-epoxide

An epoxycarotenoid of beta-carotene.


isoferulic acid

A ferulic acid consisting of trans-cinnamic acid bearing methoxy and hydroxy substituents at positions 4 and 3 respectively on the phenyl ring.


beta-erythroidine

An organic heterotetracyclic indole alkaloid isolated from the seeds and other parts of Erythrina species. It differs from the alpha isomer in having the double bond of the dihydropyranone ring located beta,gamma- to the lactone carbonyl group instead of alpha,beta-.


trimethobenzamide

The amide obtained by formal condensation of 3,4,5-trihydroxybenzoic acid with 4-[2-(N,N-dimethylamino)ethoxy]benzylamine. It is used to prevent nausea and vomitting in humans.


NITROBENZENE

A nitroarene consisting of benzene carrying a single nitro substituent. An industrial chemical used widely in the production of aniline.


2,3-dihydroxybenzenesulfonic acid

A dihydroxybenzenesulfonic acid in which the hydroxy groups are located at positions 2 and 3.


A 2-enoyl-CoA in which the double bond between positions 2 and 3 of the S-acyl group has cis- geometry.


cyclohexanecarboxylate

A monocarboxylic acid anion that is the conjugate base of cyclohexanecarboxylic acid.


diamorphine

A morphinane alkaloid that is morphine bearing two acetyl substituents on the O-3 and O-6 positions. As with other opioids, heroin is used as both an analgesic and a recreational drug. Frequent and regular administration is associated with tolerance and physical dependence, which may develop into addiction. Its use includes treatment for acute pain, such as in severe physical trauma, myocardial infarction, post-surgical pain, and chronic pain, including end-stage cancer and other terminal illnesses.


L-4-hydroxyglutamic semialdehyde

A glutamic semialdehyde that is  L-glutamic 5-semialdehyde substituted by a hydroxy group at position 4.


APOCYNIN

An aromatic ketone that is 1-phenylethanone substituted by a hydroxy group at position 4 and a methoxy group at position 3.


resorcinol

A  benzenediol that is benzene dihydroxylated at positions 1 and 3.


An undecaprenyldiphospho-N-acetylmuramoyl peptide in which the peptide moiety is L-alanyl-D-isoglutaminyl-L-lysyl-D-alanyl-D-alanine.


METHYLSELENOCYSTEINE

An L-alpha-amino acid compound having methylselanylmethyl as the side-chain.


12-dehydro-leukotriene B4

A long-chain fatty acid consisting of leukotriene B4 having a 12-keto group in place of the 12-hydroxy group.


A sialotetraosylceramide having alpha-Neu5Ac-(2->3)-beta-Gal-(1->3)-beta-GlcNAc-(1->3)-beta-Gal-(1->4)-beta-Glc as the sialotetraosyl component.


clavaldehyde

An organic heterobicyclic compound that is clavulanic acid in which the allylic alcohol group has been oxidised to the corresponding aldehyde.


(S)-methylmalonaldehydic acid

A 2-methyl-3-oxopropanoic acid that has S-configuration.


A member of the class of benzimidazoles that is benzimidazole in which the hydrogen at position 2 is replaced by an amino group.


5-hydroxyindoleacetic acid

A member of the class of indole-3-acetic acids that is  indole-3-acetic acid substituted by a hydroxy group at C-5.


thiamine(1+) aldehyde

A heteroarenecarbaldehyde that is thiamine(1+) in which the 2-hydroxyethyl group has been replaced by a 2-oxoethyl group.


AYANIN

A trimethoxyflavone that is  quercetin in which the hydroxy groups at positions 3, 4' and 7 have been replaced by methoxy groups.


A beta-D-glucoside consisting of (S)-prunasin carrying a hydroxy substituent at position 4 on the phenyl ring.


paraoxon

An aryl dialkyl phosphate where both the alkyl groups are ethyl and the aryl group is 4-nitrophenyl.


A puromycin 5'-phosphate compound lacking three methyl substituents (two from the exocyclic amino function of the adenine moiety and one from the phenolic function).


pentostatin

A member of the class of coformycins that is coformycin in which the hydroxy group at position 2' is replaced with a hydrogen. It is a drug used for the treatment of hairy cell leukaemia.


DODECANAL

A long-chain fatty aldehyde that is dodecane in which two hydrogens attached to a terminal carbon are replaced by an oxo group.


A cyanopyridine carrying the cyano group at position 2.


A member of the class of 4-pyridones that is 4-pyridone substituted with a carboxamide group at C-3 and a methyl group at N-1.


A  primary arylamine that is aniline in which the hydrogens at the 2- and 4-positions are replaced by methyl groups. A clear to yellow liquid, it is used in production of certain dyes, pesticides and other chemicals.


DDD

A chlorophenylethane that is 2,2-bis(p-chlorophenyl)ethane substituted by two chloro groups at position 1. It is a metabolite of the  organochlorine insecticide, DDT.


sulfoglucobrassicin

An indolylmethylglucosinolic acid that is glucobrassicin bearing an additional sulfo group on the indole nitrogen.


CYANIDIN

An anthocyanidin cation that is flavylium substituted at positions 3, 3', 4', 5 and 7 by hydroxy groups.


IOTYROSINE

The monoiodotyrosine that is L-tyrosine carrying an iodo-substituent at position C-3 of the benzyl group.


toluene-4-sulfonic acid

An arenesulfonic acid that is benzenesulfonic acid in which the hydrogen at position 4 is replaced by a methyl group.


keto-neuraminic acid

The open-chain form of neuraminic acid.


A hydroxyaldehyde consisting of phenylacetaldehyde having three hydroxy substituents located at the alpha-, 3- and 4-positions. It is a metabolite of noradrenaline.


A hydroxyacyl-CoA that results from the formal condensation of the thiol group of coenzyme A with the carboxy group of L-erythro-3-methylmalic acid.


acetamide

A member of the class of acetamides that results from the formal condensation of acetic acid with ammonia.


A mannan composed from D-mannan residues joined by beta-(1->4) linkages.


The intermediate in the biosynthesis of vitamin B12 from uroporphyrinogen III in which six methyl groups have been introduced into the tetrapyrrole framework, together with ring contraction and reduction.


CASTANOSPERMINE

A tetrahydroxyindolizidine alkaloid that consists of octahydroindolizine having four hydroxy substituents located at positions 1, 6, 7 and 8 (the 1S,6S,7R,8R,8aR-diastereomer).


A polymer composed of repeating 2-beta-D-glucosylribitol-1-phosphate units.


ALLISAN

A nitroaniline that is 4-nitroaniline in which the hydrogens at positions 2 and 6 are replaced by chlorines. An agricultural fungicide, it is not approved for use in the European Union.


FUCOSTEROL

A 3beta-sterol consisting of stigmastan-3beta-ol with double bonds at positions 5 and 24(28).


An acyl-CoA that results from the formal condensation of the thiol group of coenzyme A with the carboxy group of (2,3,3-trimethyl-5-oxocyclopent-3-enyl)acetic acid.


antheraxanthin

An  epoxycarotenol that is beta-carotene-3,3'-diol in which one of the one of the endocyclic double bonds has been oxidised to the corresponding epoxide. It is a neutral yellow plant pigment found in Euglenophyta.


An oxo-fatty acyl-CoA that results from the formal condensation of the thiol group of coenzyme A with the carboxylic acid group of 3-oxolauroic acid.


CHLOROACETIC ACID

A chlorocarboxylic acid that is acetic acid carrying a 2-chloro substituent.


biocytin

A  monocarboxylic acid amide that results from the formal condensation of the carboxylic acid group of biotin with the N(6)-amino group of L-lysine.


chloroacetaldehyde

Acetaldehyde substituted at C-2 by chlorine.


A derivative of aniline in which the hydrogen at position 3 has been substituted by fluorine. It is used as a pharmaceutical intermediate.


An S-alkyl-CoA having 3-hydroxy-3-methylbutyl as the S-alkyl component.


An N-acetyl-beta-D-glycosaminyl glycopeptide consisting of an N-acetyl-beta-D-glycosaminyl-(1->4)-N-acetylmuramoyl moiety attached to the amino terminus of the tetrapeptide L-alanyl-D-glutamyl-6-carboxy-L-lysyl-D-alanine via an amide linkage.


NAPHTHYLAMINE

A naphthylamine carrying the amino group at position 2.


A member of the class of pretetramides in which the only additional substituent is a methyl group at position 6.


apraclonidine

An imidazoline that is 2-amino 4,5-dihydro-1H-imidazoline in which one of the exocyclic amino hydrogens has been replaced by a 4-amino-2,6-dichlorophenyl group.


resveratrol

A stilbenol that is stilbene in which the phenyl groups are substituted at positions 3, 5, and 4' by hydroxy groups.


colchicine

A colchicine that has (S)-configuration. It is a secondary metabolite, has anti-inflammatory properties and is used to treat gout, crystal-induced joint inflammation, familial Mediterranean fever, and many other conditions.


A GDP-sugar having 6-deoxy-L-mannose as the sugar component.


S-sulfo-L-cysteine

An S-substituted L-cysteine where the S-substituent is specified as a sulfo group.


A fluorobenzoate that is the conjugate base of 4-fluorobenzoic acid.


DL-TRYPTOPHAN

An alpha-amino acid that is alanine bearing an indol-3-yl substituent at position 3.


apramycin

An aminoglycoside that is 2-deoxystreptamine that is substituted on the oxygen at position 4 by an (8R)-2-amino-8-O-(4-amino-4-deoxy-alpha-D-glucopyranosyl)-2,3,7-trideoxy-7-(methylamino)-D-glycero-alpha-D-allo-octodialdo-1,5:8,4-dipyranos-1-yl) group.


tetracycline

A broad-spectrum polyketide antibiotic produced by the Streptomyces genus of actinobacteria.


2,4,5-TRICHLOROPHENOXYACETIC ACID

A chlorophenoxyacetic acid that is phenoxyacetic acid in which the ring hydrogens at postions 2, 4 and 5 are substituted by chlorines.


D-erythrose

The D-enantiomer of erythrose.


phenyl hydrogen sulfate

An aryl sulfate that is phenol bearing an O-sulfo substituent.


Ubiquinone Qo

A derivative of benzoquinone carrying a 5-methyl substituent; and methoxy substituents at positions 2 and 3. The core structure of the ubiquinone group of compounds.


alpha-L-rhamnopyranose

An L-rhamnopyranose having alpha-configuration at the anomeric centre.


paraldehyde

A trioxane that is 1,3,5-trioxane substituted by methyl groups at positions 2, 4 and 6.


aprobarbital

A member of the class of  barbiturates that is pyrimidine-2,4,6(1H,3H,5H)-trione substituted by an isopropyl and a  prop-1-en-3-yl group at position 5.


A 3beta-sterol having the structure of desmosterol with an extra double bond at C-7--C-8.


An acetylspermidine that is 1,8-diamino-4-azaoctane in which one of the hydrogens of the amino group attached to C-8 is replaced by an acetyl group.


A mannan consisting of repeating D-mannosyl units joined via alpha-(1->6)-linkages.


melamine

A trimer of cyanamide, with a 1,3,5-triazine skeleton.


A member of the class of chalcones that is trans-chalcone substituted by a hydroxy group at position 2'.


UNCINANONE A

A member of the class of 7-hydroxyisoflavones that is 7-hydroxyisoflavone substituted by additional hydroxy groups at positions 5, 2' and 4' and a prenyl group at position 6.


A glycerophosphoglycerol in which sn-glycerol, acylated at O(2), is linked through a phospho group at O(3) to O(1) of glycerol.


PHENYLHYDRAZINE

A phenylhydrazine that is the monophenyl derivative of hydrazine.


A dichlorophenol with the chloro substituents at positions 2 and 5.


An indanone with an oxo substituent at position 2. It is a metabolite of indane.


MALTOTRIOSE

A maltotriose trisaccharide in which the glucose residue at the reducing end is in the pyranose ring form and has alpha configuration at the anomeric carbon atom..


A member of the class of glycolaldehydes that is 3,4-dihydroxymandelaldehyde in which the hydroxy group at position 4 is replaced by a methoxy group.


beta-lactam antibiotic

An organonitrogen heterocyclic antibiotic that contains a beta-lactam ring.


A D-galactosyl-N-acetyl-D-glucosaminyl-D-galactosyl-D-glucosylceramide containing beta-linkages exclusively.


chaulmoogric acid

A monounsaturated long-chain fatty acid composed of tridecanoic acid having a 2-cyclopentenyl substituent at the 13-position.


HARMALOL

A harmala alkaloid in which the harman skeleton is hydroxy-substituted at C-7 and has been reduced across the 3,4 bond.


ISOFLAVANONE

Isoflavone in which the double bond between positions 2 and 3 has been reduced to a single bond.


D-histidine

An optically active form of histidine having D-configuration.


dTDP-alpha-D-desosamine

A dTDP-sugar having 3-dimethylamino-3,4,6-trideoxy-alpha-D-glucose (alpha-D-desosamine) as the sugar component.


(E)-sinapaldehyde

A member of the class of cinnamaldehydes that is cinnamaldehyde substituted by a hydroxy group at position 4 and methoxy groups at positions 3 and 5.


A 2-oxo monocarboxylic acid that is 2-oxobutanoic acid which is substituted by a phosphonooxy group at position 4 and a hydroxy group at the 3-pro-R position.


streptamine

An amino cyclitol consisting of scyllo-inositol with the hydroxy groups at positions 1 and 3 replaced by unsubstituted amino groups.


dehydroascorbic acid

Dehydroascorbic acid having the L-configuration.


hydroxyacetone

A propanone that is acetone in which one of the methyl hydrogens is replaced by a hydroxy group.


cocaine

A tropane alkaloid obtained from leaves of the South American shrub Erythroxylon coca.


L-NNA

An L-arginine derivative that is L-arginine in which the terminal nitrogen of the guanidyl group is replaced by a nitro group.


conessine

A steroid alkaloid that is con-5-enine substituted by a N,N-dimethylamino group at position 3. It has been isolated from the plant species of the family Apocynaceae.


mesaconyl-CoA

An omega-carboxyacyl-CoA that results from the formal condensation of the thiol group of coenzyme A with the 1-carboxy group of mesaconic acid.


2-aminoisobutyric acid

A rare, non-protein amino acid and end-product of pyrimidine metabolism, excreted in urine and found in some antibiotics of fungal origin. With the exception of a few bacteria, it is non-metabolisable, and therefore used in bioassays.


estriol

A 3-hydroxy steroid that is estra-1,3,5(10)-trien-3-ol substituted by additional hydroxy groups at positions 16 and 17 (16alpha,17beta-stereoisomer).


L-glyceraldehyde

The L-enantiomer of glyceraldehyde.


A phenylacetaldehyde in which the 3 and 4 positions of the phenyl group are substituted by hydroxy groups.


An unsaturated fatty acyl-CoA that results from the formal condensation of the thiol group of coenzyme A with the carboxy group of all-cis-icosa-8,11,14-trienoic acid.


3,5-dinitro-4-hydroxyphenylpyruvic acid

A 2-oxo monocarboxylic acid that is pyruvic acid in which one of the methyl hydrogens is substituted by a 3,5-dinitro-4-hydroxyphenyl group.


A nitrile that is acetonitrile where one of the methyl hydrogens is substituted by a 2-methylphenyl group.


A member of the class of aminopyrimidines that is 4,6-diaminopyrimidine bearing an additional formamido substituent at position 5. A DNA lesion formed when DNA exposed to ionising radiation.


NITROSOBENZENE

A nitroso compound that is the nitroso derivative of benzene; a diamagnetic hybrid of singlet O2 and azobenzene.


muco-inositol

An  inositol that is cyclohexane-1,2,3,4,5,6-hexol having a (1R,2R,3r,4R,5S,6r)-configuration.


A UDP-sugar having 2-deoxyglucose as the sugar component.


3-ethoxybenzoic acid

An ethoxybenzoic acid carrying an ethoxy substituent at position 3.


BENZONITRILE

A nitrile that is hydrogen cyanide in which the hydrogen has been replaced by a phenyl group.


A 4-hydroxy-D-proline in which the hydroxy group at position 4 has S-configuration.


An O-acyl carbohydrate that is beta-D-glucose carrying sinapoyl groups at the 1- and 2-positions.


GALUTEOLIN

A glycosyloxyflavone that is luteolin substituted by a beta-D-glucopyranosyl moiety at position 7 via a glycosidic linkage.


3-methylbenzyl alcohol

A methylbenzyl alcohol that is toluene in which one of the meta hydrogens has been replaced by a hydroxymethyl group.


ELAIDIC ACID

A 9-octadecenoic acid and the trans-isomer of oleic acid.


tolbutamide

An N-sulfonylurea that consists of 1-butylurea having a tosyl group attached at the 3-position.


LINALOOL (+)

The (R)-enantiomer of linalool.


vancomycin

A complex glycopeptide from Streptomyces orientalis. It inhibits a specific step in the synthesis of the peptidoglycan layer in the Gram-positive bacteria Staphylococcus aureus and Clostridium difficile.


A medium-chain unsaturated fatty acyl-CoA that results from the formal condensation of the thiol group of coenzyme A with the carboxy group of cis,cis-dodeca-3,6-dienoic acid.


An acyl-CoA that results from the formal condensation of the thiol group of coenzyme A with the carboxy group of cyclohex-1-ene-1-carboxylic acid.


O,O-DIETHYL S-HYDROGEN PHOSPHOROTHIOATE

An organic thiophosphate that is the diethyl ester of phosphorothioic O,O,O-acid.


N-Acetylglucosamine

An N-acetyl-D-glucosamine having beta-configuration at the anomeric centre.


A macromolecule consisting of 10-formyltetrahydrofolic acid with an arbitrary number of glutamate residues attached as a polypeptide to the single existent one.


A 3-oxoacyl-CoA that results from the formal condensation of the thiol group of coenzyme A with the carboxy group of 2-hydroxy-6-oxocyclohexane-1-carboxylic acid.


FOSFRUCTOSE

A D-fructofuranose 1,6-bisphosphate with a beta-configuration at the anomeric position.


A pyrazolopyrazole that is 6,7-dihydro-1H,5H-pyrazolo[1,2-a]pyrazole-3-carboxylic acid which has been substituted at positions 2, 5 and 6 by methylsulfonyl, oxo, and amino groups, respectively, and in which the amino group has been condensed with the carboxy group of (2-amino-1,3-thiazol-4-yl)(oxo)acetic acid, the oxo group of which has been converted to the corresponding oxime O-allyl ether.


A chloroamino acid that is L-tyrosine carrying chloro- substituents at positions C-3 and C-5 of the benzyl group.


starch

The most important reserve polysaccharide found in plants. It is a glucan consisting of amylose and amylopectin.


A monomethoxyflavone that is the 8-O-methyl derivative of gossypetin .


A plastoquinol in which an all-E nonaprenyl group is attached to position 5 of 2,3-dimethylhydroquinone.


A muconic semialdehyde compound having a hydroxy substituent at the 2-position and a methyl substituent at the 5-position.


6-hydroxy-2-oxohexanoic acid

A hexanoic acid compound having an oxo substituent at the 2-position and a hydroxy substituent at the 6-position.


aldehydo-D-rhamnose

The open-chain aldehyde form of D-rhamnose.


A monohydroxyacetophenone carrying a hydroxy substituent at position 4'.


The epoxide formed from cholest-5-ene by formal addition of oxygen across the 5,6 double bond with beta-configuration at both C-5 and C-6.


beta-D-galactoside

Any D-galactoside having beta-configuration at its anomeric centre.


N-acetyl-D-galactosamine

The D-enantiomer of N-acetylgalactosamine.


A pyridinemonocarboxylic acid that is pyridine-4-carboxylic acid substituted by a methyl group, hydroxy group and formyl group at positions 2,3 and 5, respectively.


4-hydroxy-3-iodophenylpyruvic acid

A phenylpyruvic acid derivative having an iodo substituent at the 3-position and a hydroxy substituent at positions 4.


gibberellin A29

A C19-gibberellin, initially identified in Pharbitis nil. It differs from gibberellin A1 in lacking a beta-OH at C-2 but possessing one at C-3 (gibbane numberings).


A fluorobenzoyl-CoA that results from the formal condensation of the thiol group of coenzyme A with the carboxy group of 3-fluorobenzoic acid.


A hydroxypregnenolone that is pregnenolone which has been substituted by a hydroxy group at position 21.


DL-PHENYLALANINE

An aromatic amino acid that is alanine in which one of the methyl hydrogens is substituted by a phenyl group.


A 4-oxo monocarboxylic acid that is acetic acid in which one of the methyl hydrogens is substituted by a 2,2,3-trimethyl-5-oxocyclopent-3-en-1-yl group.


A diacetylchitobiosyldiphosphodolichol in which a trimannosyl group consisting of one beta-D-mannosyl and two alpha-D-mannosyl residues is attached at an unspecified position to the diacetylchitobiosyldiphosphodolichol moiety.


ARBUSCULIN A

A sesquiterpene lactone isolated from Saussureae Radix and has been shown to exhibit inhibitory activity against melanogenesis.