A 17beta-hydroxy steroid that is testosterone bearing an additional hydroxy substituent at the 6beta-position.


3-Hydroxyhexadecanoic acid

A long-chain fatty acid that is the 3-hydroxy derivative of palmitic acid.


Oxindole

An indolinone carrying an oxo group at position 2.


Carbon Tetrachloride

A chlorocarbon that is methane in which all the hydrogens have been replaced by chloro groups.


Benzene

A six-carbon aromatic annulene in which each carbon atom donates one of its two 2p electrons into a delocalised pi system. A toxic, flammable liquid byproduct of coal distillation, it is used as an industrial solvent. Benzene is a carcinogen that also damages bone marrow and the central nervous system.


Phenacetin

A member of the class of acetamides that is acetamide in which one of the hydrogens attached to the nitrogen is substituted by a 4-ethoxyphenyl group.


Hydroquinone

A benzenediol comprising benzene core carrying two hydroxy substituents para to each other.


Paclitaxel

A tetracyclic diterpenoid isolated originally from the bark of the Pacific yew tree, Taxus brevifolia. It is a mitotic inhibitor used in cancer chemotherapy. Note that the use of the former generic name 'taxol' is now limited, as Taxol is a registered trade mark.


Tolbutamide

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


A imidazolidine-2,4-dione that consists of hydantoin bearing phenyl and 4-hydroxyphenyl substituents at position 5.


A methylindole carrying a methyl substituent at position 3. It is produced during the anoxic metabolism of L-tryptophan in the mammalian digestive tract.


Coumarin

A chromenone having the keto group located at the 2-position.


Umbelliferone

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


Loperamide

A synthetic piperidine derivative, effective against diarrhoea resulting from gastroenteritis or inflammatory bowel disease.


Phenytoin

A imidazolidine-2,4-dione that consists of hydantoin bearing two phenyl substituents at position 5.


Naadp

A nicotinic acid dinucleotide that is NADP(+) in which the carboxamide group on the pyridine ring is replaced by a carboxy group.


Diguanosine tetraphosphate

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


Quercetin

A pentahydroxyflavone having the five hydroxy groups placed at the 3-, 3'-, 4'-, 5- and 7-positions. It is one of the most abundant flavonoids in edible vegetables, fruit and wine.


A 26-hydroxycholesterol in which the 25-position has R-configuration.


Quinidine

A cinchona alkaloid consisting of cinchonine with the hydrogen at the 6-position of the quinoline ring substituted by methoxy.


Glyceraldehyde

An aldotriose comprising propanal having hydroxy groups at the 2- and 3-positions. It plays role in the formation of advanced glycation end-products (AGEs), a deleterious accompaniment to ageing.


polycyclic arene

A polycyclic aromatic hydrocarbon.


Valproic Acid

A branched-chain saturated fatty acid that comprises of a propyl substituent on a pentanoic acid stem.


Methamphetamine

A member of the class of amphetamines in which the amino group of (S)-amphetamine carries a methyl substituent.


Urethane

A carbamate ester obtained by the formal condensation of ethanol with carbamic acid. It has been found in alcoholic beverages.


Sodium arsenite

An inoganic sodium salt with formula with formula NaAsO2.


Aristolochic acid

An aristolochic acid that is phenanthrene-1-carboxylic acid that is substituted by a methylenedioxy group at the 3,4 positions, by a methoxy group at position 8, and by a nitro group at position 10. It is the most abundant of the aristolochic acids and is found in almost all Aristolochia (birthworts or pipevines) species. It has been tried in a number of treatments for inflammatory disorders, mainly in Chinese and folk medicine. However, there is concern over their use as aristolochic acid is both carcinogenic and nephrotoxic.


Dexamethasone

A fluorinated steroid that is 9-fluoropregna-1,4-diene substituted by hydroxy groups at positions 11, 17 and 21, a methyl group at position 16 and oxo groups at positions 3 and 20. It is a synthetic member of the class of  glucocorticoids.


Thioacetamide

A thiocarboxamide consiting of acetamide having the oxygen replaced by sulfur.


azane;dichloroplatinum

A diamminedichloroplatinum compound in which the two ammine ligands and two chloro ligands are oriented in a cis planar configuration around the central platinum ion. An anticancer drug that interacts with, and forms cross-links between, DNA and proteins, it is used as a neoplasm inhibitor to treat solid tumours, primarily of the testis and ovary. Commonly but incorrectly described as an alkylating agent due to its mechanism of action (but it lacks alkyl groups).


Paraoxon

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


Trichloroethylene

A member of the class of  chloroethenes that is ethene substituted by chloro groups at positions 1, 1 and 2.


Paraquat

An organic cation that consists of 4,4'-bipyridine bearing two N-methyl substituents loctated at the 1- and 1'-positions.


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


Phenobarbital

A member of the class of barbiturates, the structure of which is that of barbituric acid substituted at C-5 by ethyl and phenyl groups.


Propofol

A phenol resulting from the formal substitution of the hydrogen at the 2 position of 1,3-diisopropylbenzene by a hydroxy group.


Carbamazepine

A dibenzoazepine that is 5H-dibenzo[b,f]azepine carrying a carbamoyl substituent at the azepine nitrogen, used as an anticonvulsant.


Butyraldehyde

A member of the class of  butanals that consists of propane bearing a formyl substituent at the 1-position. The parent of the class of butanals.


Caffeic acid phenethyl ester

An alkyl caffeate ester in which 2-phenylethyl is the alkyl component.


Piroxicam

A monocarboxylic acid amide resulting from the formal condensation of the carboxy group of 4-hydroxy-2-methyl-2H-1,2-benzothiazine-3-carboxylic acid 1,1-dioxide with the exocyclic nitrogen of 2-aminopyridine. A non-steroidal anti-inflammatory drug of the oxicam class, it is used to relieve pain and works by preventing the production of endogenous prostaglandins involved in the mediation of pain, stiffness, tenderness and swelling.


Bortezomib

L-Phenylalaninamide substituted at the amide nitrogen by a 1-(dihydroxyboranyl)-3-methylbutyl group and at N(alpha) by a pyrazin-2-ylcarbonyl group. It is a dipeptidyl boronic acid that reversibly inhibits the 26S proteasome.


N-Nitrosodiethylamine

A nitrosamine that is N-ethylethanamine substituted by a nitroso group at the N-atom.


Leflunomide

A monocarboxylic acid amide obtained by formal condensation of the carboxy group of 5-methyl-1,2-oxazole-4-carboxylic acid with the anilino group of 4-(trifluoromethyl)aniline. The prodrug of teriflunomide.


cyclosporin A

A cyclic nonribosomal peptide of eleven amino acids; an immunosuppressant drug widely used in post-allogeneic organ transplant to reduce the activity of the patient's immune system, and therefore the risk of organ rejection. Also causes reversible inhibition of immunocompetent lymphocytes in the G0- and G1-phase of the cell cycle.


Ibuprofen

A monocarboxylic acid that is propionic acid in which one of the hydrogens at position 2 is substituted by a 4-(2-methylpropyl)phenyl group.


Isotretinoin

A retinoic acid that is all-trans-retinoic acid in which the double bond which is alpha,beta- to the carboxy group is isomerised to Z configuration. A synthetic retinoid, it is used for the treatment of severe cases of acne and other skin diseases.


Cyclophosphamide

A phosphorodiamide that is 1,3,2-oxazaphosphinan-2-amine 2-oxide substituted by two 2-chloroethyl groups at the amino nitrogen atom.


Cannabidiol

An cannabinoid that is cyclohexene which is substituted by a methyl group at position 1, a 2,6-dihydroxy-4-pentylphenyl group at position 3, and a prop-1-en-2-yl group at position 4.


Azathioprine

A thiopurine that is 6-mercaptopurine in which the mercapto hydrogen is replaced by a 1-methyl-4-nitroimidazol-5-yl group. It is a prodrug for mercaptopurine and is used as an immunosuppressant, prescribed for the treatment of inflammatory conditions and after organ transplantation and also for treatment of Crohn's didease and MS.


Dronabinol

A diterpenoid that is 6a,7,8,10a-tetrahydro-6H-benzo[c]chromene substituted at position 1 by a hydroxy group, positions 6, 6 and 9 by methyl groups and at position 3 by a pentyl group. The principal psychoactive constituent of the cannabis plant, it is used for treatment of anorexia associated with AIDS as well as nausea and vomiting associated with cancer chemotherapy.


Diazinon

A member of the class of  pyrimidines that is pyrimidine carrying an isopropyl group at position 2, a methyl group at position 6 and a (diethoxyphosphorothioyl)oxy group at position 4.


Prednisolone

A glucocorticoid that is prednisone in which the oxo group at position 11 has been reduced to the corresponding beta-hydroxy group. It is a drug metabolite of prednisone.


Sertraline

A member of the class of tetralins that is tetralin which is substituted at positions 1 and 4 by a methylamino and a 3,4-dichlorophenyl group, respectively (the S,S diastereoisomer). A selective serotonin-reuptake inhibitor (SSRI), it is administered orally as the hydrochloride salt as an antidepressant for the treatment of depression, obsessive-compulsive disorder, panic disorder and post-traumatic stress disorder.


The mono(2-ethylhexyl) ester of benzene-1,2-dicarboxylic acid.


Bilirubin

A member of the class of  biladienes that is a linear tetrapyrrole with the dipyrrole units being of both exovinyl and endovinyl type. A product of heme degradation, it is produced in the reticuloendothelial system by the reduction of biliverdin and transported to the liver as a complex with serum albumin.


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.


A pentacyclic ortho- and peri-fused polycyclic arene consisting of a dihydrocyclopenta[ij]tetraphene ring system with a methyl substituent at the 3-position.


Emodin

A trihydroxyanthraquinone that is 9,10-anthraquinone which is substituted by hydroxy groups at positions 1, 3, and 8 and by a methyl group at position 6. It is present in the roots and barks of numerous plants (particularly rhubarb and buckthorn), moulds, and lichens. It is an active ingredient of various Chinese herbs.


Chlorpromazine

A substituted phenothiazine in which the ring nitrogen at position 10 is attached to C-3 of an N,N-dimethylpropanamine moiety.


Arachidonic Acid

A long-chain fatty acid that is a C20, polyunsaturated fatty acid having four (Z)-double bonds at positions 5, 8, 11 and 14.


N-Nitrosomorpholine

A nitrosamine that is morpholine in which the hydrogen attached to the nitrogen is replaced by a nitroso group. A carcinogen and mutagen, it is found in snuff tobacco.


Tetrabromobisphenol A

A bromobisphenol that is 4,4'-methanediyldiphenol in which the methylene hydrogens are replaced by two methyl groups and the phenyl rings are substituted by bromo groups at positions 2, 2', 6 and 6'. It is a brominated flame retardant.


Puerarin

A hydroxyisoflavone that is  isoflavone substituted by hydroxy groups at positions 7 and 4' and a beta-D-glucopyranosyl residue at position 8 via a C-glycosidic linkage.


Chrysin

A dihydroxyflavone in which the two hydroxy groups are located at positions 5 and 7.


Malathion

A diester that is diethyl succinate in which position 2 is substituted by a (dimethoxyphosphorothioyl)thio group.


Daunorubicin

A natural product found in Actinomadura roseola.


Nitroglycerin

A nitroglycerol that is glycerol in which the hydrogen atoms of all three hydroxy groups are replaced by nitro groups. It acts as a prodrug, releasing nitric oxide to open blood vessels and so alleviate heart pain.


Diquat

The organic cation formed formally by addition of an ethylene bridge between the nitrogen atoms of 2,2'-bipyridine. Most often available as the dibromide.


A member of the class of  benzodioxoles that is 1,3-benzodioxole substituted by a 2-(methylamino)propyl group at position 5.


All-trans-4-oxoretinoic acid

A retinoid that consists of all-trans-retinoic acid bearing an oxo substituent at position 4 on the cyclohexenyl ring.


methylmercury compound

An  alkylmercury compound in which the  alkyl group specified is methyl.


Acrylamide

A member of the class of acrylamides that results from the formal condensation of acrylic acid with ammonia.


Fenthion

An organic thiophosphate that is O,O-dimethyl hydrogen phosphorothioate in which the hydrogen atom of the hydroxy group is replaced by a 3-methyl-4-(methylsulfanyl)phenyl group. It exhibits  acaricidal and insecticidal activities.


Diltiazem

A 5-[2-(dimethylamino)ethyl]-2-(4-methoxyphenyl)-4-oxo-2,3,4,5-tetrahydro-1,5-benzothiazepin-3-yl acetate in which both stereocentres have S configuration. A calcium-channel blocker and vasodilator, it is used as the hydrochloride in the management of angina pectoris and hypertension.


Sevoflurane

An ether compound having fluoromethyl and 1,1,1,3,3,3-hexafluoroisopropyl as the two alkyl groups.


Vincristine

A vinca alkaloid with formula C46H56N4O10 found in the Madagascar periwinkle, Catharanthus roseus. It is used (commonly as the corresponding sulfate salt)as a chemotherapy drug for the treatment of leukaemia, lymphoma, myeloma, breast cancer and head and neck cancer.


Lidocaine

The monocarboxylic acid amide resulting from the formal condensation of N,N-diethylglycine with 2,6-dimethylaniline.


androgen

A sex hormone that stimulates or controls the development and maintenance of masculine characteristics in vertebrates by binding to androgen receptors.


The amino acid zwitterion formed from 3,3',5-triiodo-L-thyronine by tranfer of a proton from the carboxy group to the amino group. It is the major species at pH 7.3.


Mercury

Elemental mercury of oxidation state zero.


Diethyltoluamide

A monocarboxylic acid amide resulting from the formal condensation of the carboxy group of m-toluic acid with the nitrogen of diethylamine. First developed by the U.S. Army in 1946 for use by military personnel in insect-infested areas, it is the most widely used insect repellent worldwide.


Propionaldehyde

An aldehyde that consists of ethane bearing a formyl substituent. The parent of the class of propanals.


Acrolein

An enal that is prop-2-ene with an oxo group at position 1.


Morphine

A morphinane alkaloid that is a highly potent opiate analgesic psychoactive drug. Morphine acts directly on the central nervous system (CNS) to relieve pain but has a high potential for addiction, with tolerance and both physical and psychological dependence developing rapidly. Morphine is the most abundant opiate found in Papaver somniferum (the opium poppy).


Toluene

The simplest member of the class toluenes consisting of a benzene core which bears a single methyl substituent.


The E (trans) stereoisomer of 4-hydroxynon-2-enal; it is the primary alpha,beta-unsaturated hydroxyalkenal produced by lipid peroxidation in cells.


Thiram

An organic disulfide that results from the formal oxidative dimerisation of N,N-dimethyldithiocarbamic acid. It is widely used as a fungicidal seed treatment.


L-Sulforaphane

A sulforaphane in which the sulfinyl group has R configuration. Naturally occurring compound found in brocolli that acts as a potent inducer of phase II detoxification enzymes.


Chrysene

An ortho-fused polycyclic arene found commonly in the coal tar.


Buspirone

An azaspiro compound that is 8-azaspiro[4.5]decane-7,9-dione substituted at the nitrogen atom by a 4-(piperazin-1-yl)butyl group which in turn is substituted by a pyrimidin-2-yl group at the N(4) position.


Cyfluthrin

A carboxylic ester obtained by formal condensation between 3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylic acid and (4-fluoro-3-phenoxyphenyl)(hydroxy)acetonitrile.


Calcifediol

A hydroxycalciol that is calciol in which the hydrogen at position 25 has been replaced by a hydroxy group. A prehormone resulting from the oxidation of calciol in the liver, it is further hydroxylated in the kidney to give calcitriol, the active form of vitamin D3.


Sarin

A racemate composed of equal amounts of (R)- and (S)-sarin. A potent and irreversible inhibitor of acetylcholinesterase that is toxic to the nervous system and is employed as a chemical warfare agent.


Isoniazid

A carbohydrazide obtained by formal condensation between pyridine-4-carboxylic acid and hydrazine.


Equilenin

A 3-hydroxy steroid that is estrone which carries two double bonds at positions 6 and 8. It is found in the urine of pregnant mare's and extensively used for estrogen replacement therapy in postmenopausal women.


Chloroquine

An aminoquinoline that is quinoline which is substituted at position 4 by a [5-(diethylamino)pentan-2-yl]amino group at at position 7 by chlorine. It is used for the treatment of malaria, hepatic amoebiasis, lupus erythematosus, light-sensitive skin eruptions, and rheumatoid arthritis.


Zidovudine

A pyrimidine 2',3'-dideoxyribonucleoside compound having a 3'-azido substituent and thymine as the nucleobase.


Diclofenac

A monocarboxylic acid consisting of phenylacetic acid having a (2,6-dichlorophenyl)amino group at the 2-position.


Tacrolimus monohydrate

A hydrate that is the monohydrate form of tacrolimus.


Vinylidene chloride

A member of the class of chloroethenes that is ethene in which both of the hydrogens attached to one of the carbons are replaced by chlorines.


Linalool, (+/-)-

A monoterpenoid that is octa-1,6-diene substituted by methyl groups at positions 3 and 7 and a hydroxy group at position 3. It has been isolated from plants like Ocimum canum.


Thalidomide

A dicarboximide that is isoindole-1,3(2H)-dione in which the hydrogen attached to the nitrogen is substituted by a 2,6-dioxopiperidin-3-yl group.


Norepinephrine

The R-enantiomer of noradrenaline.


Benz(a)anthracene

An angular ortho-fused polycyclic arene consisting of four fused benzene rings.


Sulindac

A monocarboxylic acid that is 1-benzylidene-1H-indene which is substituted at positions 2, 3, and 5 by methyl, carboxymethyl, and fluorine respectively, and in which the phenyl group of the benzylidene moiety is substituted at the para position by a methylsulfinyl group. It is a prodrug for the corresponding sulfide, a non-steroidal anti-inflammatory drug, used particularly in the treatment of acute and chronic inflammatory conditions.


Lithocholic acid

A monohydroxy-5beta-cholanic acid with a alpha-hydroxy substituent at position 3. It is a bile acid obtained from chenodeoxycholic acid by bacterial action.


Crotonaldehyde

An enal consisting of propene having a formyl group at the 1-position.


Ketamine

A member of the class of cyclohexanones in which one of the hydrogens at position 2 is substituted by a 2-chlorophenyl group, while the other is substituted by a methylamino group.


Sulindac sulfide

An  aryl sulfide that is a metabolite of  sulindac. A non-steroidal anti-inflammatory drug, which also has anticancer activity.


Gefitinib

A member of the class of quinazolines that is quinazoline which is substituted by a (3-chloro-4-fluorophenyl)nitrilo group, 3-(morpholin-4-yl)propoxy group and a methoxy group at positions 4,6 and 7, respectively. An EGFR kinase inhibitor used for the treatment of non-small cell lung cancer.


Sorafenib

A member of the class of phenylureas that is urea in which one of the nitrogens is substituted by a 4-chloro-3-trifluorophenyl group while the other is substituted by a phenyl group which, in turn, is substituted at the para position by a [2-(methylcarbamoyl)pyridin-4-yl]oxy group.


Cypermethrin

A carboxylic ester resulting from the formal condensation between 3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylic acid and the alcoholic hydroxy group of hydroxy(3-phenoxyphenyl)acetonitrile.


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.


aldehyde

A compound RC(=O)H, in which a carbonyl group is bonded to one hydrogen atom and to one R group.


Nicardipine

A dihydropyridine that is 1,4-dihydropyridine substituted by a methyl, {2-[benzyl(methyl)amino]ethoxy}carbonyl, 3-nitrophenyl, methoxycarbonyl and methyl groups at positions 2, 3, 4, 5 and 6, respectively.


Dapsone

A  sulfone that is diphenylsulfone in which the hydrogen atom at the 4 position of each of the phenyl groups is substituted by an amino group. It is active against a wide  range of bacteria, but is mainly employed for its actions against Mycobacterium leprae, being used as part of multidrug regimens in the treatment of all forms of leprosy.


Scopoletin

A hydroxycoumarin that is umbelliferone bearing a methoxy substituent at position 6.


Dronedarone

A member of the class of  1-benzofurans used for the treatment of  cardiac arrhythmias.


Carvedilol

A member of the class of carbazoles that is an adrenergic antagonist with non-selective beta- and alpha-1 receptor blocking properties which helps in the management of congestive heart failure.


Regorafenib

A pyridinecarboxamide obtained by condensation of 4-[4-({[4-chloro-3-(trifluoromethyl)phenyl]carbamoyl}amino)-3-fluorophenoxy]pyridine-2-carboxylic acid with methylamine. Used for for the treatment of metastatic colorectal cancer in patients who have previously received chemotherapy, anti-EGFR or anti-VEGF therapy.


Sirolimus

A macrolide lactam isolated from Streptomyces hygroscopicus consisting of a 29-membered ring containing 4 trans double bonds, three of which are conjugated. It is an antibiotic, immunosupressive and antineoplastic agent.


Baicalein

A trihydroxyflavone with the hydroxy groups at positions C-5, -6 and -7.


Methadone

A ketone that is heptan-3-one substituted by a dimethylamino group at position 6 and two phenyl groups at position 4.


Ursodeoxycholic acid

A bile acid found in the bile of bears (Ursidae) as a conjugate with taurine. Used therapeutically, it prevents the synthesis and absorption of cholesterol and can lead to the dissolution of gallstones.


Fluorescein

A xanthene dye that is highly fluorescent, detectable even when present in minute quantities. Used forensically to detect traces of blood, in analytical chemistry as an indicator in silver nitrate titrations and in microscopy.


Fenvalerate

A carboxylic ester obtained by formal condensation between 2-(4-chlorophenyl)-3-methylbutyric acid and cyano(3-phenoxyphenyl)methanol.


Losartan

A biphenylyltetrazole where a 1,1'-biphenyl group is attached at the 5-position and has an additional trisubstituted imidazol-1-ylmethyl group at the 4'-position


Theophylline

A dimethylxanthine having the two methyl groups located at positions 1 and 3. It is structurally similar to caffeine and is found in green and black tea.


tert-Butyl Hydroperoxide

An alkyl hydroperoxide in which the alkyl group is tert-butyl. It is widely used in a variety of oxidation processes.


Cyhalothrin

A carboxylic ester obtained by formal condensation between 3-(2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylic acid and cyano(3-phenoxyphenyl)methanol.


Simvastatin

A member of the class of hexahydronaphthalenes that is lovastatin in which the 2-methylbutyrate ester moiety has been replaced by a 2,2-dimethylbutyrate ester group. It is used as a cholesterol-lowering and anti-cardiovascular disease drug.


An  epoxide and metabolite of carbamazepine.


Promethazine

A  tertiary amine that is a substituted phenothiazine in which the ring nitrogen at position 10 is attached to C-3 of an N,N-dimethylpropan-2-amine moiety.


estrogen

A hormone that stimulates or controls the development and maintenance of female sex characteristics in mammals by binding to oestrogen receptors. The oestrogens are named for their importance in the oestrous cycle. The oestrogens that occur naturally in the body, notably estrone, estradiol, estriol, and estetrol are steroids. Other compounds with oestrogenic activity are produced by plants (phytoestrogens) and fungi (mycoestrogens); synthetic compounds with oestrogenic activity are known as xenoestrogens.


Tetrachloroethylene

A chlorocarbon that is tetrachloro substituted ethene.


Disulfiram

An organic disulfide that results from the formal oxidative dimerisation of N,N-diethyldithiocarbamic acid.  A multi-enzyme inhibitor that is used in alcohol aversion therapy and also exhibits anticancer properties.


An imidazoquinoline that is 3H-imidazo[4,5-f]quinoline substituted by a methyl group at position 3 and an amino group at position 2.


A tetrahydropyridine that is 1,2,3,6-tetrahydropyridine substituted by a methyl group at position 1 and a phenyl group at position 4.


Thioridazine

A phenothiazine derivative having a methylsulfanyl subsitituent at the 2-position and a (1-methylpiperidin-2-yl)ethyl] group at the N-10 position.


Dichloroacetic acid

An organochlorine compound comprising acetic acid carrying two chloro substituents at the 2-position. It occurs in nature in seaweed, Asparagopsis taxiformis.


Propranolol

A propanolamine that is propan-2-ol substituted by a propan-2-ylamino group at position 1 and a naphthalen-1-yloxy group at position 3.


Butachlor

An aromatic amide that is 2-choro-N-(2,6-diethylphenyl)acetamide in which the amide nitrogen has been replaced by a butoxymethyl group.


Oxycodone

A semisynthetic opioid of formula C18H21NO4 that is derived from thebaine.  It is a moderately potent opioid analgesic, generally used for relief of moderate to severe pain.


Okadaic acid

A polycyclic ether that is produced by several species of dinoflagellates, and is known to accumulate in both marine sponges and shellfish.  A polyketide, polyether derivative of a C38 fatty acid, it is one of the primary causes of diarrhetic shellfish poisoning (DSP). It is a potent inhibitor of specific protein phosphatases and is known to have a variety of negative effects on cells.


Beclomethasone

A 17alpha-hydroxy steroid that is prednisolone in which the hydrogens at the 9alpha and 16beta positions are substituted by a chlorine and a methyl group, respectively.


chlorohydrocarbon

A compound derived from a hydrocarbon by replacing at least one hydrogen atom with a chlorine atom.


Ibrutinib

A member of the class of acrylamides that is (3R)-3-[4-amino-3-(4-phenoxyphenyl)pyrazolo[3,4-d]pyrimidin-1-yl]piperidine in which the piperidine nitrogen is replaced by an acryloyl group. A selective and covalent inhibitor of the enzyme Bruton's tyrosine kinase, it is used for treatment of B-cell malignancies.


p-Toluidine

An aminotoluene in which the amino substituent is para to the methyl group.


Riddelline

A macrodiolide that is 13,19-didehydrosenecionan bearing two additional hydroxy substituents at positions 12 and 18 as well as two additional oxo groups at positions 11 and 16.


A toluene meta-diisocyanate in which the isocyanato groups are at positions 2 and 4 relative to the methyl group on the benzene ring.


Fluoxetine

A racemate comprising equimolar amounts of (R)- and (S)-fluoxetine. A selective serotonin reuptake inhibitor (SSRI), it is used (generally as the hydrochloride salt) for the treatment of depression (and the depressive phase of bipolar disorder), bullimia nervosa, and obsessive-compulsive disorder.


Pendimethalin

A member of the class of substituted anilines that is N-(pentan-3-yl)aniline bearing two additional nitro substituents at positions 2 and 6 as well as two methyl substituents at positions 3 and 4. A herbicide used to control most annual grasses and many annual broad-leaved weeds.


Olanzapine

A benzodiazepine that is 10H-thieno[2,3-b][1,5]benzodiazepine substituted by a methyl group at position 2 and a 4-methylpiperazin-1-yl group at position 4.


O-Anisidine

A substituted aniline that is aniline in which the hydrogen ortho to the amino group has been replaced by a methoxy group. It is used as a chemical intermediate in the synthesis of azo pigments and dyes.


Celecoxib

A member of the class of pyrazoles that is 1H-pyrazole which is substituted at positions 1, 3 and 5 by 4-sulfamoylphenyl, trifluoromethyl and p-tolyl groups, respectively. A cyclooxygenase-2 inhibitor, it is used in the treatment of arthritis.


Naloxone

A synthetic morphinane alkaloid that is morphinone in which the enone double bond has been reduced to a single bond, the hydrogen at position 14 has been replaced by a hydroxy group, and the methyl group attached to the nitrogen has been replaced by an allyl group. A specific opioid antagonist, it is used (commonly as its hydrochloride salt) to reverse the effects of opioids, both following their use of opioids during surgery and in cases of known or suspected opioid overdose.


Styrene

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


Naproxen

A methoxynaphthalene that is 2-methoxynaphthalene substituted by a carboxy ethyl group at position 6. Naproxen is a non-steroidal anti-inflammatory drug commonly used for the reduction of pain, fever, inflammation  and stiffness caused by conditions such as osteoarthritis, kidney stones, rheumatoid arthritis, psoriatic arthritis, gout, ankylosing spondylitis, menstrual cramps, tendinitis, bursitis, and for the treatment of primary dysmenorrhea. It works by inhibiting both the COX-1 and COX-2 enzymes.


Benzbromarone

1-Benzofuran substituted at C-2 and C-3 by an ethyl group and a 3,5-dibromo-4-hydroxybenzoyl group respectively. An inhibitor of CYP2C9, it is used as an anti-gout medication.


Pioglitazone

A member of the class of thiazolidenediones that is 1,3-thiazolidine-2,4-dione substituted by a benzyl group at position 5 which in turn is substituted by a 2-(5-ethylpyridin-2-yl)ethoxy group at position 4 of the phenyl ring. It exhibits hypoglycemic activity.


Imipramine

A dibenzoazepine that is 5H-dibenzo[b,f]azepine substituted by a 3-(dimethylamino)propyl group at the nitrogen atom.


tert-Butyl ethyl ether

An ether having ethyl and tert-butyl as the two alkyl components. It is used as an engine fuel additive to reduce emissions of carbon monoxide and soot.


Alfacalcidol

A member of the class of D3 vitamins that is calciol in which the hydrogen at the 1alpha position is replaced by a hydroxy group. It is an active metabolite of cholecalciferol, which performs important functions in regulation of the calcium balance and the bone metabolism.


Omeprazole

A member of the class of benzimidazoles that is 1H-benzimidazole which is substituted by a [4-methoxy-3,5-dimethylpyridin-2-yl)methyl]sulfinyl group at position 2 and a methoxy group at position 5.


Irinotecan

A member of the class of pyranoindolizinoquinolines that is the carbamate ester obtained by formal condensation of the carboxy group of [1,4'-bipiperidine]-1'-carboxylic acid with the phenolic hydroxy group of (4S)-4,11-diethyl-4,9-dihydroxy-1H-pyrano[3',4':6,7]indolizino[1,2- hydrochloride]quinoline-3,14-dione. Used (in the form of its hydrochloride salt trihydrate) in combination with fluorouracil and leucovorin, for the treatment of patients with metastatic adenocarcinoma of the pancreas after disease progression following gemcitabine-based therapy. It is converted via hydrolysis of the carbamate linkage to its active metabolite, SN-38, which is ~1000 times more active.


Ritonavir

An L-valine derivative that is L-valinamide in which alpha-amino group has been acylated by a [(2-isopropyl-1,3-thiazol-4-yl)methyl]methylcarbamoyl group and in which a hydrogen of the carboxamide amino group has been replaced by a (2R,4S,5S)-4-hydroxy-1,6-diphenyl-5-{[(1,3-thiazol-5-ylmethoxy)carbonyl]amino}hexan-2-yl group. A CYP3A inhibitor and antiretroviral drug from the protease inhibitor class used to treat HIV infection and AIDS, it is often used as a fixed-dose combination with another protease inhibitor, lopinavir. Also used in combination with dasabuvir sodium hydrate, ombitasvir and paritaprevir (under the trade name Viekira Pak) for treatment of chronic hepatitis C virus genotype 1 infection as well as cirrhosis of the liver.


The Z-isomer of imidacloprid.


Aconitine

A diterpenoid that is 20-ethyl-3alpha,13,15alpha-trihydroxy-1alpha,6alpha,16beta-trimethoxy-4-(methoxymethyl)aconitane-8,14alpha-diol having acetate and benzoate groups at the 8- and 14-positions respectively.


A  butadiene with unsaturation at positions 1 and 3.


D-(-)-Fructose

The open-chain form of D-fructose.


Verapamil

A tertiary amino compound that is 3,4-dimethoxyphenylethylamine in which the hydrogens attached to the nitrogen are replaced by a methyl group and a 4-cyano-4-(3,4-dimethoxyphenyl)-5-methylhexyl group.


N-Methylformamide

A member of the class of formamides  having a N-methyl substituent.


Imiquimod

An imidazoquinoline fused [4,5-c] carrying isobutyl and amino substituents at N-1 and C-4 respectively. A prescription medication, it acts as an immune response modifier and is used to treat genital warts, superficial basal cell carcinoma, and actinic keratosis.


Ifosfamide

The simplest member of the class of  ifosfamides that is 1,3,2-oxazaphosphinan-2-amine 2-oxide substituted by 2-chloroethyl groups on both the nitrogen atoms respectively. It is a nitrogen mustard alkylating agent used in the treatment of advanced breast cancer.


Oxazepam

A 1,4-benzodiazepinone that is 1,3-dihydro-2H-1,4-benzodiazepin-2-one substituted by a chloro group at position 7, a hydroxy group at position 3 and phenyl group at position 5.


Acetohexamide

An N-sulfonylurea that is urea in which a hydrogen attached to one of the nitrogens is replaced by a p-acetylphenylsulfonyl group, while a hydrogen attached to the other nitrogen is replaced by a cyclohexyl group.


Carmustine

A member of the class of N-nitrosoureas that is 1,3-bis(2-chloroethyl)urea in which one of the nitrogens is substituted by a nitroso group.


Erythromycin

An erythromycin that consists of erythronolide A having 2,6-dideoxy-3-C-methyl-3-O-methyl-alpha-L-ribo-hexopyranosyl and 3,4,6-trideoxy-3-(dimethylamino)-beta-D-xylo-hexopyranosyl residues attahced at positions 4 and 6 respectively.


Methyl parathion

A C-nitro compound that is  4-nitrophenol substituted by a (dimethoxyphosphorothioyl)oxy group at position 4.


Atorvastatin

A dihydroxy monocarboxylic acid that is a member of the drug class known as statins, used primarily for lowering blood cholesterol and for preventing cardiovascular diseases.


A bromoalkane that is ethane carrying bromo substituents at positions 1 and 2. It is produced by marine algae.


Phenethyl isothiocyanate

An isothiocyanate having a phenethyl group attached to the nitrogen. It is a naturally occurring compound found in some cruciferous vegetables (e.g. watercress) and is known to possess anticancer properties.


A manganese cation that is monoatomic and has a formal charge of +4.


Methylphenidate

A racemate comprising equimolar amounts of the two threo isomers of methyl phenyl(piperidin-2-yl)acetate. A central stimulant and indirect-acting sympathomimetic, is used (generally as the hydrochloride salt) in the treatment of hyperactivity disorders in children and for the treatment of narcolepsy.


Chloroform

A one-carbon compound that is methane in which three of the hydrogens are replaced by chlorines.


Desipramine

A dibenzoazepine consisting of 10,11-dihydro-5H-dibenzo[b,f]azepine substituted on nitrogen with a 3-(methylamino)propyl group.


Diazepam

A 1,4-benzodiazepinone that is 1,3-dihydro-2H-1,4-benzodiazepin-2-one substituted by a chloro group at position 7, a methyl group at position 1 and a phenyl group at position 5.


Carvacrol

A phenol that is a natural monoterpene derivative of cymene. An inhibitor of  bacterial growth, it is used as a food additive. Potent activator of the human ion channels transient receptor potential V3 (TRPV3) and A1 (TRPA1).


Bioallethrin

A partly enantiopure variant of allethrin consisting of a mixture of two allethrin isomers (1R,trans;1R and 1R,trans;1S) in an approximate ratio of 1:1. Widely registered mosquito adulticide and spatial repellent. Bioallethrin is a synthetic pyrethroid used as a pesticide against household pest insects such as mosquitoes, houseflies and cockroaches.


A chloroaniline that consists of two 2-chloroaniline units joined by a methylene bridge.


4-Vinylcyclohexene dioxide

The diepoxide of 4-vinylcyclohexene.


Ethosuximide

A  dicarboximide that is pyrrolidine-2,5-dione in which the hydrogens at position 3 are substituted by one methyl and one ethyl group. An antiepileptic, it is used in the treatment of absence seizures and may be used for myoclonic seizures, but is ineffective against tonic-clonic seizures.


The parent of the class of 2-acetamidofluorenes, being an ortho-fused polycyclic arene that consists of 9H-fluorene bearing an acetamido substituent at position 2. It is a carcinogenic and mutagenic derivative of fluorene.


Hexanal

A saturated fatty aldehyde that is hexane in which one of the terminal methyl group has been mono-oxygenated to form the corresponding aldehyde.


Phenanthrene

A polycyclic aromatic hydrocarbon composed of three fused benzene rings which takes its name from the two terms 'phenyl' and 'anthracene.'


A tautomer of uric acid having oxo groups at C-2 and C-8 and a hydroxy group at C-6.


Tanespimycin

A 19-membered macrocyle that is geldanamycin in which the methoxy substituent attached to the benzoquinone moiety has been replaced by an allylamino group. It is a potent inhibitor of heat shock protein 90 (Hsp90). A less toxic analogue than geldanamycin, it induces apoptosis and displays antitumour effects.


A monohydroxyquinoline that is quinoline substituted by a hydroxy group at position 8. Its fungicidal properties are used for the control of grey mould on vines and tomatoes.


Meiqx

An imidazoquinoxaline that is 3H-imidazo[4,5-f]quinoxaline substituted at positions 3 and 8 by methyl groups and at position 2 by an amino group. A mutagenic compound found in cooked beef.


Tacrine

A member of the class of acridines that is 1,2,3,4-tetrahydroacridine substituted by an amino group at position 9. It is used in the treatment of Alzheimer's disease.


Methylene Chloride

A member of the class of chloromethanes that is methane in which two of the hydrogens have been replaced by chlorine. A dense, non-flammible colourless liquid at room temperature (b.p. 40degreeC, d = 1.33) which is immiscible with water, it is widely used as a solvent, a paint stripper, and for the removal of caffeine from coffee and tea.


Hydralazine

The 1-hydrazino derivative of phthalazine; a direct-acting vasodilator that is used as an antihypertensive agent.


Cisaprida

The amide resulting from formal condensation of 4-amino-5-chloro-2-methoxybenzoic acid with cis-1-[3-(4-fluorophenoxy)propyl]-3-methoxypiperidin-4-amine. It has been used (as its monohydrate or as its tartrate) for the treatment of gastro-oesophageal reflux disease and for non-ulcer dyspepsia, but its propensity to cause cardiac arrhythmias resulted in its complete withdrawal from many countries, including the U.K., and restrictions on its use elsewhere.


A hydroxybenzaldehyde carrying a hydroxy substituent at position 3.


Acrylonitrile

A nitrile that is hydrogen cyanide in which the hydrogen has been replaced by an ethenyl group.


Bufalin

A 14beta-hydroxy steroid that is bufan-20,22-dienolide having hydroxy substituents at the 5beta- and 14beta-positions. It has been isolated from the skin of the toad Bufo bufo.


Farnesol

A farnesane sesquiterpenoid that is dodeca-2,6,10-triene substituted by methyl groups at positions 3, 7 and 11 and a hydroxy group at position 1.


Methyl tert-butyl ether

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


bile acids

Any member of a group of hydroxy steroids occuring in bile, where they are present as the sodium salts of their amides with glycine or taurine. In mammals bile acids almost invariably have 5beta-configuration, while in lower vertebrates, some bile acids, known as allo-bile acids, have 5alpha-configuration.


Artemisinin

A sesquiterpene lactone obtained from sweet wormwood, Artemisia annua, which is used as an antimalarial for the treatment of multi-drug resistant strains of falciparum malaria.


Aniline

A primary arylamine in which an amino functional group is substituted for one of the benzene hydrogens.


Thiabendazole

A member of the class of benzimidazoles carrying a 1,3-thiazol-4-yl substituent at position 2. A mainly post-harvest fungicide used to control a wide range of diseases including Aspergillus, Botrytis, Cladosporium and Fusarium.


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.


A dichloroaniline having the two chloro-substituents at the 3- and 4-positions.


Metolachlor

A racemate that consists of equimolar amounts of (R)- and (S)-metolachlor.


N,N-Dimethylformamide

A member of the class of formamides that is formamide in which the amino hydrogens are replaced by methyl groups.


Tofacitinib

A pyrrolopyrimidine that is pyrrolo[2,3-d]pyrimidine substituted at position 4 by an N-methyl,N-(1-cyanoacetyl-4-methylpiperidin-3-yl)amino moiety. Used as its citrate salt to treat moderately to severely active rheumatoid arthritis.


Cannabigerol

A member of the class of resorcinols that is resorcinol which is substituted by a (2E)-3,7-dimethylocta-2,6-dien-1-yl group at position 2 and by a pentyl group at position 5. It is a natural product found in Cannabis sativa and Helichrysum species.


A nitroarene that is pyrene substituted at the 1-position by a nitro group. A by-product of combustion,  it is the predominant nitrated polycyclic aromatic hydrocarbon emitted in a diesel engine.


Menthol

Any secondary alcohol that is one of the eight possible diastereoisomers of 5-methyl-2-(propan-2-yl)cyclohexan-1-ol.


m-Xylene

A xylene carrying methyl groups at positions 1 and 3.


A dichlorobenzene carrying chloro groups at positions 1 and 4.


Acenocoumarol

A hydroxycoumarin that is warfarin in which the hydrogen at position 4 of the phenyl substituent is replaced by a nitro group.


Astemizole

A piperidine compound having a 2-(4-methoxyphenyl)ethyl group at the 1-position and an N-[(4-fluorobenzyl)benzimidazol-2-yl]amino group at the 4-position.


Quinine

A cinchona alkaloid that is cinchonidine in which the hydrogen at the 6-position of the quinoline ring is substituted by methoxy.


P-Cresol

A cresol that consists of toluene substituted by a hydroxy group at position 4. It is a metabolite of aromatic amino acid metabolism produced by intestinal microflora in humans and animals.


SULFASALAZINE

An azobenzene consisting of diphenyldiazene having a carboxy substituent at the 4-position, a hydroxy substituent at the 3-position and a 2-pyridylaminosulphonyl substituent at the 4'-position.


Tramadol

A 2-[(dimethylamino)methyl]-1-(3-methoxyphenyl)cyclohexanol in which both stereocentres have R-configuration; the (R,R)-enantiomer of the racemic opioid analgesic tramadol, it exhibits ten-fold higher analgesic potency than the (S,S)-enantiomer.


A naphthylamine carrying the amino group at position 2.


The enal that is (E)-non-2-enal substituted with an oxo group at C-4.


Vandetanib

A quinazoline that is 7-[(1-methylpiperidin-4-yl)methoxy]quinazoline bearing additional methoxy and 4-bromo-2-fluorophenylamino substituents at positions 6 and 4 respectively. Used for the treatment of symptomatic or progressive medullary thyroid cancer in patients with unresectable locally advanced or metastatic disease.


Ethylene Glycol

A 1,2-glycol compound produced via reaction of ethylene oxide with water.


Irbesartan

A  biphenylyltetrazole that is an angiotensin II receptor antagonist used mainly for the treatment of hypertension.


Aminoglutethimide

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


Meloxicam

A benzothiazine that is piroxicam in which the pyridin-2-yl group is replaced by a 5-methyl-1,3-thiazol-2-yl group. A non-steroidal anti-inflammatory drug and selective inhibitor of COX-2, it is used particularly for the management of rheumatoid arthritis.


Heroin

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.


Arsenic acid

An arsenic oxoacid comprising one oxo group and three hydroxy groups attached to a central arsenic atom.


Tangeretin

A pentamethoxyflavone flavone with methoxy groups at positions 4', 5, 6 , 7 and 8.


Midazolam

An imidazobenzodiazepine that is 4H-imidazo[1,5-a][1,4]benzodiazepine which is substituted by a methyl, 2-fluorophenyl and chloro groups at positions 1, 6 and 8, respectively.


poly(vinyl chloride)

A polymer composed of repeating chloroethyl units.


Acetochlor

A monocarboxylic acid amide that is N-phenylacetamide carrying an ethyl and a methyl group at positions 2 and 6 respectively on the benzene ring while one of the methyl hydrogens as well as the hydrogen attached to the nitrogen atom have been replaced by a chloro and an ethoxymethyl group respectively.


6-Mercaptopurine monohydrate

A member of the class of purines that is 6,7-dihydro-1H-purine carrying a thione group at position 6. An adenine analogue, it is used in the treatment of acute lymphocytic leukemia (ALL), chronic myeloid leukemia (CML), Crohn's disease, and ulcerative colitis.


Benzidine

A member of the class of biphenyls that is 1,1'-biphenyl in which the hydrogen at the para-position of each phenyl group has been replaced by an amino group.


Valsartan

A monocarboxylic acid amide consisting of L-valine in which the amino hydrogens have been replaced by a pentanoyl and a  [2'-(1H-tetrazol-5-yl)biphenyl]-4-yl]methyl group. It exhibits  antihypertensive activity.


A dihydroxybenzaldehyde carrying hydroxy groups at positions 2 and 5.


An oxysterol that is cholesterol substituted by a hydroxy group at position 20.


Oltipraz

A 1,2-dithiole that is 3H-1,2-dithiole-3-thione substituted at positions 4 and 5 by methyl and pyrazin-2-yl groups respectively.


arenecarbaldehyde

Any aldehyde in which the carbonyl group is attached to an aromatic moiety.


Pentobarbital

A member of the class of barbiturates, the structure of which is that of barbituric acid substituted at C-5 by ethyl and sec-pentyl groups.


Cerivastatin

(3R,5S)-3,5-dihydroxyhept-6-enoic acid in which the (7E)-hydrogen is substituted by a 4-(4-fluorophenyl)-2,6-diisopropyl-5-(methoxymethyl)pyridin-3-yl group. Formerly used (as its sodium salt) to lower cholesterol and prevent cardiovascular disease, it was withdrawn from the market worldwide in 2001 following reports of a severe form of muscle toxicity.


4-Terpineol, (+/-)-

A terpineol that is 1-menthene carrying a hydroxy substituent at position 4.


Eldecalcitol

A hydroxycalciol that is calcitriol with a 3-hydroxypropoxy group at position 2.


Mycophenolic acid

A member of the class of 2-benzofurans that is 2-benzofuran-1(3H)-one which is substituted at positions 4, 5, 6, and 7 by methyl, methoxy, (2E)-5-carboxy-3-methylpent-2-en-1-yl, and hydroxy groups, respectively. It is an antibiotic produced by Penicillium brevi-compactum, P. stoloniferum, P. echinulatum and related species. An immunosuppressant, it is widely used (partiularly as its sodium salt and as the 2-(morpholin-4-yl)ethyl ester prodrug, mycophenolate mofetil) to prevent tissue rejection following organ transplants and for the treatment of certain autoimmune diseases.


Isopropyl Alcohol

A secondary alcohol that is propane in which one of the hydrogens attached to the central carbon is substituted by a hydroxy group.


Galangin

A 7-hydroxyflavonol with additional hydroxy groups at positions 3 and 5 respectively; a growth inhibitor of breast tumor cells.


Doconexent

A docosahexaenoic acid having six cis-double bonds at positions 4, 7, 10, 13, 16 and 19.


A chromanone that is the 3,4-dihydro derivative of coumarin.


Alectinib

An organic heterotetracyclic compound that is 6,6-dimethyl-5,6-dihydro-11H-benzo[b]carbazol-11-one carrying additional cyano, 4-(morpholin-4-yl)piperidin-1-yl and ethyl substituents at positions 3, 8 and 9 respectively. Used (as the hydrochloride salt) for the treatment of patients with anaplastic lymphoma kinase-positive, metastatic non-small cell lung cancer.


n-HEXANE

An unbranched alkane containing six carbon atoms.


Nadide

Abbreviation for nicotinamide-adenine dinucleotide when its oxidation state is unknown or unspecified. It is used in metabolic pathways like glycolysis and citric acid cycle.


Quinacrine

A member of the class of acridines that is acridine substituted by a chloro group at position 6, a methoxy group at position 2 and a [5-(diethylamino)pentan-2-yl]nitrilo group at position 9.


Citronellal

A monoterpenoid, the main component of citronella oil which gives it its distinctive lemon aroma.


L-Homocysteine

A sulfur-containing amino acid consisting of a glycine core with a 2-mercaptoethyl side-chain.


Halothane

A haloalkane comprising ethane having three flouro substituents at the 1-position as well as bromo- and chloro substituents at the 2-position.


Paroxetine

A benzodioxole that consists of piperidine bearing 1,3-benzodioxol-5-yloxy)methyl and 4-fluorophenyl substituents at positions 3 and 4 respectively; the (3S,4R)-diastereomer. Highly potent and selective 5-HT uptake inhibitor that binds with high affinity to the serotonin transporter (Ki = 0.05 nM). Ki values are 1.1, 350 and 1100 nM for inhibition of [3H]-5-HT, [3H]-l-NA and [3H]-DA uptake respectively. Displays minimal affinity for alpha1-, alpha2- or beta-adrenoceptors, 5-HT2A, 5-HT1A, D2 or H1 receptors at concentrations below 1000 nM, however displays weak affinity for muscarinic ACh receptors (Ki = 42 nM). Antidepressant and anxiolytic in vivo.


A chloroaniline in which the chloro atom is para to the aniline amino group.


Fluticasone

A trifluorinated corticosteroid used in the form of its propionate ester for treatment of allergic rhinitis.


retinoid

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


Nelfinavir

An aryl sulfide that is used (as its mesylate salt) for treatment of HIV and also exhibits some anticancer properties.


Carfentanil

A monocarboxylic acid amide resulting from the formal condensation of the aryl amino group of methyl 4-anilino-1-(2-phenylethyl)piperidine-4-carboxylate with propanoic acid.


Abacavir

A 2,6-diaminopurine that is (1S)-cyclopent-2-en-1-ylmethanol in which the pro-R hydrogen at the 4-position is substituted by a 2-amino-6-(cyclopropylamino)-9H-purin-9-yl group. A nucleoside analogue reverse transcriptase inhibitor (NRTI) with antiretroviral activity against HIV, it is used (particularly as the sulfate) with other antiretrovirals in combination therapy of HIV infection.


Acetone

A methyl ketone that consists of propane bearing an oxo group at C2.


Artesunic acid

An artemisinin derivative that is the hemisuccinate ester of the lactol resulting from the reduction of the lactone carbonyl group of artemisinin. It is used, generally as the sodium salt, for the treatment of malaria.


Pantoprazole

A member of the class of  benzimidazoles that is 1H-benzimidazole substituted by a difluoromethoxy group at position 5 and a [(3,4-dimethoxypyridin-2-yl)methyl]sulfinyl group at position 2.


A 17beta-hydroxy steroid, being 17beta-estradiol methoxylated at C-2.


Loratadine

A benzocycloheptapyridine that is 6,11-dihydro-5H-benzo[5,6]cyclohepta[1,2-b]pyridine substituted by a chloro group at position 8 and a 1-(ethoxycarbonyl)piperidin-4-ylidene group at position 11. It is a H1-receptor antagonist commonly employed in the treatment of allergic disorders.


Chrysophanic acid

A trihydroxyanthraquinone that is chrysazin with a methyl substituent at C-3. It has been isolated from Aloe vera and exhibits antiviral and anti-inflammatory activity.


Spermine

A polyazaalkane that is tetradecane in which the carbons at positions 1, 5, 10 and 14 are replaced by nitrogens. Spermine has broad actions on cellular metabolism.


Metoprolol

A propanolamine that is 1-(propan-2-ylamino)propan-2-ol substituted by a  4-(2-methoxyethyl)phenoxy group at position 1.


Alizarin

A dihydroxyanthraquinone that is anthracene-9,10-dione in which the two hydroxy groups are located at positions 1 and 2.


progestin

A synthetic progestogen.


A monounsaturated fatty aldehyde that is (2E)-non-2-ene which is carrying an oxo group at position 1.


Flucloxacillin

A penicillin compound having a 6beta-[3-(2-chloro-6-fluorophenyl)-5-methyl-1,2-oxazole-4-carboxamido] side-chain.


Dehydroepiandrosterone sulfate

A steroid sulfate that is the 3-sulfooxy derivative of dehydroepiandrosterone.


A member of the class of phenols that is phenol which is substituted at the para- position by an octyl group.


Phencyclidine

A member of the class of piperidines that is piperidine in which the nitrogen is substituted with a 1-phenylcyclohexyl group.  Formerly used as an anaesthetic agent, it exhibits both hallucinogenic and neurotoxic effects.


Verbenone, (+)-

A 4,6,6-trimethylbicyclo[3.1.1]hept-3-en-2-one in which both chiral centres have R configuration. It is a component of Spanish verbena oil, from Verbena triphylla.


Almotriptan

An indole compound having a 2-(dimethylamino)ethyl group at the 3-position and a (pyrrolidin-1-ylsulfonyl)methyl group at the 5-position.


Risperidone

A member of the class of pyridopyrimidines that is 2-methyl-6,7,8,9-tetrahydropyrido[1,2-a]pyrimidin-4-one carrying an additional 2-[4-(6-fluoro-1,2-benzoxazol-3-yl)piperidin-1-yl]ethyl group at position 2.


Felbamate

The bis(carbamate ester) of 2-phenylpropane-1,3-diol. An anticonvulsant, it is used in the treatment of epilepsy.


A nitroaniline carrying a nitro group at position 4.


Masitinib

A member of the class of benzamides that is the carboxamide resulting from the formal condensation of the carboxy group of 4-[(4-methylpiperazin-1-yl)methyl]benzoic acid with the primary amino group of 4-methyl-N(3)-[4-(pyridin-3-yl)-1,3-thiazol-2-yl]benzene-1,3-diamine. It is a highly selective oral tyrosine kinase inhibitor.


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.


Ametryn

A methylthio-1,3,5-triazine that is 2-(methylsulfanyl)-1,3,5-triazine substituted by an ethylamino and an isopropylamino group at positions 4 and 6 respectively.


Ethacrynic acid

An aromatic ether that is phenoxyacetic acid in which the phenyl ring is substituted by chlorines at positions 2 and 3, and by a 2-methylidenebutanoyl group at position 4. It is a loop diuretic used to treat high blood pressure resulting from diseases such as congestive heart failure, liver failure, and kidney failure. It is also a glutathione S-transferase (EC 2.5.1.18) inhibitor.


Fluconazole

A member of the class of  triazoles that is propan-2-ol substituted at position 1 and 3 by 1H-1,2,4-triazol-1-yl groups and at position 2 by a 2,4-difluorophenyl group. It is an antifungal drug used for the treatment of mucosal candidiasis and for systemic infections including systemic candidiasis, coccidioidomycosis, and cryptococcosis.


clonidine (amino form)

A clonidine that is 4,5-dihydro-1H-imidazol-2-amine in which one of the amino hydrogens is replaced by a 2,6-dichlorophenyl group.


Esculetin

A  hydroxycoumarin that is umbelliferone in which the hydrogen at position 6 is substituted by a hydroxy group. It is used in filters for absorption of ultraviolet light.


Nobiletin

A methoxyflavone that is flavone substituted by methoxy groups at positions 5, 6, 7, 8, 3' and 4' respectively.


Thiourea

The simplest member of the thiourea class, consisting of urea with the oxygen atom substituted by sulfur.


Norclozapine

A dibenzodoazepine substituted with chloro and piperazino groups which is a major metabolite of clozapine; a potent and selective 5-HT2C serotonin receptor antagonist.


A naphthol carrying a hydroxy group at position 2.


Ethylenediaminetetraacetate

A tetracarboxylic acid anion formed by deprotonation of all four carboxy groups in ethylenediaminetetraacetic acid (EDTA).


Saquinavir

An aspartic acid derivative obtained by formal condensation of the primary amino group of (2S,3R)-4-[(3S,4aS,8aS)-3-(tert-butylcarbamoyl)octahydroisoquinolin-2(1H)-yl]-3-hydroxy-1-phenylbutan-2-ylamine with the carboxy group of N(2)(-quinolin-2-ylcarbonyl)-L-asparagine. An inhibitor of HIV-1 protease.


A dichlorobenzene carrying chloro substituents at positions 1 and 2.


Methyl Salicylate

A benzoate ester that is the methyl ester of salicylic acid.


Monobromobimane

A pyrazolopyrazole that consists of 1H,7H-pyrazolo[1,2-a]pyrazole-1,7-dione bearing three methyl substituents at positions 2, 5 and 6 as well as a bromomethyl substituent at the 3-position.


Styrene oxide

An epoxide that is oxirane in which one of the hydrogens has been replaced by a phenyl group.


Primaquine

An N-substituted diamine that is pentane-1,4-diamine substituted by a 6-methoxyquinolin-8-yl group at the N(4) position. It is a drug used in the treatment of malaria and Pneumocystis pneumonia.


Tienilic acid

An aromatic ketone that is 2,3-dichlorophenoxyacetic acid in which the hydrogen at position 4 on the benzene ring is replaced by a thiophenecarbonyl group. A loop diuretic used to treat hypertension, it was withdrawn from the market in 1982 due to links with hepatitis.


Tinidazole

1H-imidazole substituted at C-1 by a (2-ethylsulfonyl)ethyl group, at C-2 by a methyl group and at C-5 by a nitro group.  It is used as an antiprotozoal, antibacterial agent.


Amodiaquine

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


Sulfobromophthalein

An organosulfonic acid that consists of phthalide bearing four bromo substituents at positions 4, 5, 6 and 7 as well as two 4-hydroxy-3-sulfophenyl groups both located at position 1.


Ketoprofen

An oxo monocarboxylic acid that consists of propionic acid substituted by a 3-benzoylphenyl group at position 2.


monounsaturated fatty acid

Any fatty acid with one double or triple bond in the fatty acid chain and singly bonded carbon atoms in the rest of the chain. MUFAs have positive effects on the cardiovascular system, and in diabetes treatment.


NADP

Abbreviation for nicotinamide-adenine dinucleotide phosphate when its oxidation state is unknown or unspecified.


A member of the class of phenols that is phenol substituted with a  tert-butyl group at position 4.


Nitrendipine

A  dihydropyridine that is 1,4-dihydropyridine substituted by methyl groups at positions 2 and 6, a 3-nitrophenyl group at position 4, a ethoxycarbonyl group at position 3 and a methoxycarbonyl group at position 5. It is a calcium-channel blocker used in the treatment of hypertension.


o-Toluidine

An aminotoluene in which the amino substituent is ortho to the methyl group.


Scutellarein

Flavone substituted with hydroxy groups at C-4', -5, -6 and -7.


Chlorobenzene

The simplest member of the class of monochlorobenzenes, that is benzene in which a single hydrogen has been substituted by a chlorine.


Chlorambucil

A monocarboxylic acid that is butanoic acid substituted at position 4 by a 4-[bis(2-chloroethyl)amino]phenyl group. A chemotherapy drug that can be used in combination with the antibody obinutuzumab for the treatment of chronic lymphocytic leukemia.


Zolpidem

An imidazo[1,2-a]pyridine compound having a 4-tolyl group at the 2-position, an N,N-dimethylcarbamoylmethyl group at the 3-position and a methyl substituent at the 6-position.


Sodium Nitrate

The inorganic nitrate salt of sodium.


Glipizide

An N-sulfonylurea that is glyburide in which the (5-chloro-2-methoxybenzoyl group is replaced by a (5-methylpyrazin-2-yl)carbonyl group. An oral hypoglycemic agent, it is used in the treatment of type 2 diabetes mellitus.


Romidepsin

A cyclodepsipeptide consisting of the cyclic disulfide of (2Z)-2-aminobut-2-enoyl, L-valyl, (3S,4E)-3-hydroxy-7-sulfanylhept-4-enoyl, D-valyl and D-cysteinyl residues coupled in sequence and cyclised head-to tail.


Butanoic acid, 2,3-dihydroxypropyl ester

A 1-monoglyceride resulting from the formal esterification of butyric acid with one of the primary hydroxy groups of glycerol. The R enantiomer is bioactive.


Cotinine

An N-alkylpyrrolidine that consists of N-methylpyrrolidinone bearing a pyridin-3-yl substituent at position C-5 (the 5S-enantiomer). It is an alkaloid commonly found in Nicotiana tabacum.


carotenoid

One of a class of tetraterpenoids (C40), formally derived from the acyclic parent, psi,psi-carotene by hydrogenation, dehydrogenation, cyclization, oxidation, or combination of these processes. This class includes carotenes, xanthophylls and certain compounds that arise from rearrangement of the skeleton of psi,psi-carotene or by loss of part of this structure. Retinoids are excluded.


A ketohexose bisphosphate that is D-fructose substituted by phosphate groups at positions 1 and 6.


A cholestanoid that consists of cholesterol bearing an oxo substituent at position 7.


Zaleplon

A pyrazolo[1,5-a]pyrimidine having a nitrile group at position 3 and a 3-(N-ethylacetamido)phenyl substituent at the 7-position.


A member of the class of 2-nitroanisoles that is anisole in which one of the hydrogens ortho to the methoxy group is replaced by a nitro group.


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.


Cobicistat

A monocarboxylic acid amide obtained by formal condensation of the carboxy group of (2S)-2-({[(2-isopropyl-1,3-thiazol-4-yl)methyl](methyl)carbamoyl}amino)-4-(morpholin-4-yl)butanoic acid with the amino group of 1,3-thiazol-5-ylmethyl [(2R,5R)-5-amino-1,6-diphenylhexan-2-yl]carbamate. Acts as a pharmacoenhancer in treatment of HIV-1 by inhibiting P450 enzymes that metabolise other medications..


Mefenamic Acid

An aminobenzoic acid that is anthranilic acid in which one of the hydrogens attached to the nitrogen is replaced by a 2,3-dimethylphenyl group. Although classed as a non-steroidal anti-inflammatory drug, its anti-inflammatory properties are considered to be minor. It is used to relieve mild to moderate pain, including headaches, dental pain, osteoarthritis and rheumatoid arthritis.


An imidazopyridine that is 1H--imidazo[4,5-b]pyridine which is substituted at positions 1, 2, and 6 by methyl, hydoxyamino, and phenyl groups, respectively. The active metabolite of the dietary carcinogen PhIP.


A member of the class of hydroxybiphenyls that is biphenyl substituted by a hydroxy group at position 2. It is generally used as a post-harvest fungicide for citrus fruits.


A macromolecule composed of repeating gamma-linked L-glutamyl units.


Itraconazole

An N-arylpiperazine that is cis-ketoconazole in which the imidazol-1-yl group is replaced by a 1,2,4-triazol-1-yl group and in which the actyl group attached to the piperazine moiety is replaced by a p-[(+-)1-sec-butyl-5-oxo-1,5-dihydro-4H-1,2,4-triazol-4-yl]phenyl group. A potent P-glycoprotein and CYP3A4 inhibitor, it is used as an antifungal drug for the treatment of various fungal infections, including aspergillosis, blastomycosis, candidiasis, chromoblastomycosis, coccidioidomycosis, cryptococcosis, histoplasmosis, and sporotrichosis.


O-Xylene

A xylene substituted by methyl groups at positions 1 and 2.


Clopidogrel

A thienopyridine that is 4,5,6,7-tetrahydrothieno[3,2-c]pyridine in which the hydrogen attached to the nitrogen is replaced by an o-chlorobenzyl group, the methylene hydrogen of which is replaced by a  methoxycarbonyl group (the S enantiomer). A P2Y12 receptor antagonist, it is used to inhibit blood clots and prevent heart attacks.


4-(2-Aminoethyl)pyrocatechol [4-(2-aminoethyl)benzene-1,2-diol] and derivatives formed by substitution.


Isatin

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


Safrole

A member of the class of benzodioxoles that is 1,3-benzodioxole which is substituted by an allyl group at position 5. It is found in several plants, including black pepper, cinnamon and nutmeg, and is present in several essential oils, notably that of sassafras. It has insecticidal properties and has been used as a topical antiseptic. Although not thought to pose a significant carcinogenic risk to humans, findings of weak carcinogenicity in rats have resulted in the banning of its (previously widespread) use in perfumes and soaps, and as a food additive.


Cabozantinib

A dicarboxylic acid diamide that is N-phenyl-N'-(4-fluorophenyl)cyclopropane-1,1-dicarboxamide in which the hydrogen at position 4 on the phenyl ring is substituted by a (6,7-dimethoxyquinolin-4-yl)oxy group. A multi-tyrosine kinase inhibitor, used (as its malate salt) for the treatment of progressive, metastatic, medullary thyroid cancer.


amine

A compound formally derived from ammonia by replacing one, two or three hydrogen atoms by hydrocarbyl groups.


A bornane monoterpenoid that is 1,7,7-trimethylbicyclo[2.2.1]heptane substituted by a hydroxy group at position 2.


Buprenorphine

A morphinane alkaloid that is 7,8-dihydromorphine 6-O-methyl ether in which positions 6 and 14 are joined by a -CH2CH2- bridge, one of the hydrogens of the N-methyl group is substituted by cyclopropyl, and a hydrogen at position 7 is substituted by a 2-hydroxy-3,3-dimethylbutan-2-yl group. It is highly effective for the treatment of opioid use disorder and is also increasingly being used in the treatment of chronic pain.


The (E)-isomer of oct-2-enal.


Vitamin U

A sulfonium betaine that is a conjugate base of S-methyl-L-methionine obtained by the deprotonation of the carboxy group.


Atenolol

An ethanolamine compound having a (4-carbamoylmethylphenoxy)methyl group at the 1-position and an N-isopropyl substituent.


Alpha-Terpineol

A terpineol that is propan-2-ol substituted by a 4-methylcyclohex-3-en-1-yl group at position 2.


D-Citronellol

A citronellol that is oct-6-ene substituted by a hydroxy group at position 1 and methyl groups at positions 3 and 7 (the 3R-enantiomer).


Efavirenz

1,4-Dihydro-2H-3,1-benzoxazin-2-one substituted at the 4 position by cyclopropylethynyl and trifluoromethyl groups (S configuration) and at the 6 position by chlorine. A non-nucleoside reverse transcriptase inhibitor with activity against HIV, it is used with other antiretrovirals for combination therapy of HIV infection.


Fentanyl

A monocarboxylic acid amide resulting from the formal condensation of the aryl amino group of N-phenyl-1-(2-phenylethyl)piperidin-4-amine with propanoic acid.


Quinalizarin

A tetrahydroxyanthraquinone having the four hydroxy groups at the 1-, 2-, 5- and 8-positions.


Felodipine

The mixed (methyl, ethyl) diester of 4-(2,3-dichlorophenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylic acid. A calcium-channel blocker, it lowers blood pressure by reducing peripheral vascular resistance through a highly selective action on smooth muscle in arteriolar resistance vessels. It is used in the management of hypertension and angina pectoris.


Allyl isothiocyanate

An isothiocyanate with the formula CH2=CHCH2N=C=S. A colorless oil with boiling point 152degreeC, it is responsible for the pungent taste of mustard, horseradish, and wasabi.


Hyodeoxycholic acid

A member of the class of 5beta-cholanic acids that is (5beta)-cholan-24-oic acid substituted by alpha-hydroxy groups at positions 3 and 6.


P-Xylene

A xylene with methyl groups at positions 1 and 4.


Busulfan

A methanesulfonate ester that is butane-1,4-diol in which the hydrogens of the hydroxy groups are replaced by methanesulfonyl groups. An alkylating antineoplastic agent, it is used for the treatment of chronic myeloid leukemia (although it has been largely replaced by newer drugs). It is also used as an insect sterilant.


Ellipticine

A organic heterotetracyclic compound that is pyrido[4,3-b]carbazole carrying two methyl substituents at positions 5 and 11.


Bromomethane

A one-carbon compound in which the carbon is attached by single bonds to three hydrogen atoms and one bromine atom. It is produced naturally by marine algae.


Doxifluridine

A pyrimidine 5'-deoxyribonucleoside that is 5-fluorouridine in which the hydroxy group at the 5' position is replaced by a hydrogen. It is an  oral prodrug of the antineoplastic agent 5-fluorouracil. Designed to circumvent the rapid degradation of 5-fluorouracil by dihydropyrimidine dehydrogenase in the gut wall, it is converted into 5-fluorouracil in the presence of pyrimidine nucleoside phosphorylase.


Vitamin K

Any member of a group of fat-soluble 2-methyl-1,4-napthoquinones that exhibit biological activity against vitamin K deficiency. Vitamin K is required for the synthesis of prothrombin and certain other blood coagulation factors.


5,5'-Dithiobis(2-nitrobenzoic acid)

An organic disulfide that results from the formal oxidative dimerisation of 2-nitro-5-thiobenzoic acid. An indicator used to quantify the number or concentration of thiol groups.


Piclamilast

A monocarboxylic acid amide resulting from the formal condensation of the carboxy group of 3-(cyclopentyloxy)-4-methoxybenzoic acid with the primary amino group of 3,5-dichloropyridin-4-amine.


alpha-Maltose

A maltose that has alpha-configuration at the reducing end anomeric centre.


Sulfaphenazole

A sulfonamide that is sulfanilamide in which the sulfonamide nitrogen is substituted by a 1-phenyl-1H-pyrazol-5-yl group. It is a selective inhibitor of cytochrome P450 (CYP) 2C9 isozyme, and antibacterial agent.


Cumene hydroperoxide

A peroxol that is cumene in which the alpha-hydrogen is replaced by a hydroperoxy group.


Diazoxon

An  organic phosphate that is diethyl hydrogen phosphate in which the hydrogen of the hydroxy group has been replaced by a 6-methyl-2-(propan-2-yl)pyrimidin-4-yl group. It is a metabolite of the pesticide diazinon.


Yohimbine

An indole alkaloid with alpha2-adrenoceptor antagonist activity. It is produced by Corynanthe johimbe and Rauwolfia serpentina.


sulfonamide

An amide of a sulfonic acid RS(=O)2NR'2.


Oseltamivir

A cyclohexenecarboxylate ester that is the ethyl ester of oseltamivir acid. An antiviral prodrug (it is hydrolysed to the active free carboxylic acid in the liver), it is used to slow the spread of influenza.


Albendazole

A carbamate ester that is methyl 1H-benzimidazol-2-ylcarbamate substituted by a propylsulfanyl group at position 5. It is commonly used in the treatment of parasitic worm infestations.


lecithin

A lipid-rich mixture containing glycerol, fatty acids, phosphoric acid and other components.


Trimethoprim

An aminopyrimidine antibiotic whose structure consists of pyrimidine 2,4-diamine and 1,2,3-trimethoxybenzene moieties linked by a methylene bridge.


GRANISETRON

A monocarboxylic acid amide resulting from the formal condensation of the carboxy group of 1-methyl-1H-indazole-3-carboxylic acid with the primary amino group of (3-endo)-9-methyl-9-azabicyclo[3.3.1]nonan-3-amine. A selective 5-HT3 receptor antagonist, it is used (generally as the monohydrochloride salt) to manage nausea and vomiting caused by cancer chemotherapy and radiotherapy, and to prevent and treat postoperative nausea and vomiting.


Cryptoxanthin

A carotenol that exhibits antioxidant activity. It has been isolated from fruits such as papaya and oranges.


Proguanil

A biguanide compound which has isopropyl and p-chlorophenyl substituents on the terminal N atoms. A prophylactic antimalarial drug, it works by inhibiting the enzyme dihydrofolate reductase, which is involved in the reproduction of the malaria parasites Plasmodium falciparum and P. vivax within the red blood cells.


Codeine

A  morphinane alkaloid found in the opium poppy, Papaver somniferum var. album; has analgesic, anti-tussive and anti-diarrhoeal properties.


Carveol

A limonene monoterpenoid that is cyclohex-2-en-1-ol substituted by a methyl group at position 2 and a prop-1-en-2-yl group at position 5.


A four-carbon alkane-alpha,omega-diamine. It is obtained by the breakdown of amino acids and is responsible for the foul odour of putrefying flesh.


Sulfamethoxazole

An isoxazole (1,2-oxazole) compound having a methyl substituent at the 5-position and a 4-aminobenzenesulfonamido group at the 3-position.


A glycerophospholipid, where R1 and R2 are acyl chains and R3 any of the groups that represent the different phospholipid classes (choline, ethanolamine, glycerol, etc).


icosanoid

Any member of the group of signalling molecules arising from oxidation of the three C20 essential fatty acids (EFAs) icosapentaenoic acid (EPA), arachidonic acid (AA) and dihomo-gamma-linolenic acid (DGLA).


Sinensetin

A pentamethoxyflavone that is flavone substituted by methoxy groups at positions 5, 6, 7, 3' and 4' respectively.


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.


Metoclopramide

A member of the class of  benzamides resulting from the formal condensation of 4-amino-5-chloro-2-methoxybenzoic acid with the primary amino group of N,N-diethylethane-1,2-diamine.


Etoricoxib

A member of the class of bipyridines that is 2,3'-bipyridine which is substituted at the 3, 5, and 6' positions by 4-(methylsulfonyl)phenyl, chlorine, and methyl groups, respectively.


Mephenytoin

An imidazolidine-2,4-dione (hydantoin) in which the imidazolidine nucleus carries a methyl group at N-3 and has ethyl and phenyl substituents at C-5. An anticonvulsant, it is no longer available in the USA or the UK but is still studied largely because of its interesting hydroxylation polymorphism.


Trifluralin

A substituted aniline that is N,N-dipropylaniline substituted by a nitro groups at positions 2 and 6 and a trifluoromethyl group at position 4. It is an agrochemical used as a pre-emergence herbicide.


Theobromine

A dimethylxanthine having the two methyl groups located at positions 3 and 7. A purine alkaloid derived from the cacao plant, it is found in chocolate, as well as in a number of other foods, and is a vasodilator, diuretic and heart stimulator.


Procainamide

A benzamide that is 4-aminobenzamide substituted on the amide N by a 2-(diethylamino)ethyl group.  It is a pharmaceutical antiarrhythmic agent used for the medical treatment of cardiac arrhythmias.


Spermidine

A triamine that is the 1,5,10-triaza derivative of decane.


A member of the class of nitrosamines that is butan-1-ol substituted by a pyridin-3-yl group at position 1 and by a methyl(nitroso)amino group at position 4. It is a major metabolite of nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), which is a carcinogen found in tobacco and responsible for inducing lung cancer in smokers.


Acacetin

A monomethoxyflavone that is the 4'-methyl ether derivative of apigenin.


A nitrile that is benzonitrile which is substituted by chlorines at positions 2 and 6. A cellulose synthesis inhibitor, it is used as a pre-emergent and early post-emergent herbicide.


Nitrofurantoin

An imidazolidine-2,4-dione that is hydantoin substituted at position 1 by a [(5-nitro-2-furyl)methylene]amino group. An antibiotic that damages bacterial DNA.


The D-enantiomer of aldehydo-mannose.


4-Aminobenzoic acid

An aminobenzoic acid in which the amino group is para to the carboxy group.


Phytol

A diterpenoid that is hexadec-2-en-1-ol substituted by methyl groups at positions 3, 7, 11 and 15.


Benzphetamine

Dextroamphetamine in which the the hydrogens attached to the amino group are substituted by a methyl and a benzyl group. A sympathomimetic agent with properties similar to dextroamphetamine, it is used as its hydrochloride salt in the treatment of obesity.


Bupropion

An aromatic ketone that is propiophenone carrying a tert-butylamino group at position 2 and a chloro substituent at position 3 on the phenyl ring.


unsaturated fatty acid

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


A C-nitro compound that is benzaldehyde substituted at the para-position with a nitro group.


Mefloquine

An organofluorine compound that consists of quinoline bearing trifluoromethyl substituents at positions 2 and 8 as well as a (2-piperidinyl)hydroxymethyl substituent at position 4.


A hydroxyflavonoid in which the flavone nucleus is substituted at position 7 by a hydroxy group.


Nitrazepam

A 1,4-benzodiazepinone that is 1,3-dihydro-2H-1,4-benzodiazepin-2-one which is substituted at positions 5 and 7 by phenyl and nitro groups, respectively. It is used as a hypnotic for the short-term management of insomnia and for the treatment of epileptic spasms in infants (West's syndrome).


Tetranabinex

A diverse group of pharmacologically active secondary metabolite characteristic to Cannabis plant as well as produced naturally in the body by humans and animals. Cannabinoids contain oxygen as a part of the heterocyclic ring or in the form of various functional groups. They are subdivided on the basis of their origin.


insecticide

Strictly, a substance intended to kill members of the class Insecta.  In common usage, any substance used for preventing, destroying, repelling or controlling insects.


Any benzoquinone derived from 2,3-dimethoxy-5-methylbenzoquinone; one of a group of naturally occurring homologues. The redox-active quinoid moiety usually carries a polyprenoid side chain at position 6, the number of isoprenoid units in which is species-specific. Ubiquinones are involved in the control of mitochondrial electron transport, and are also potent anti-oxidants.


o-Cresol

A cresol that is phenol substituted by a methyl group at position 2. It is a minor urinary metabolite of toluene.


Dihydroorotic acid

A pyrimidinemonocarboxylic acid that results from the base-catalysed cyclisation of N(alpha)-carbethoxyasparagine.


heterocyclic compound

A cyclic compound having as ring members atoms of at least two different elements.


A 2-hydroxy steroid that consists of 17beta-estradiol having an additional hydroxy group at position 2.


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.


Fluvoxamine

An oxime O-ether that is benzene substituted by a (1E)-N-(2-aminoethoxy)-5-methoxypentanimidoyl group at position 1 and a trifluoromethyl group at position 4. It is a selective serotonin reuptake inhibitor that is used for the treatment of obsessive-compulsive disorder.


A HPETE that consists of (5Z,8Z,11Z,13E)-icosatetraenoic acid in which the hydroperoxy group is located at position 15.


glucocorticoid

Glucocorticoids are a class of steroid hormones that regulate a variety of physiological processes, in particular control of the concentration of glucose in blood.


A 1-methylxanthine tautomer where the imidazole proton is located at the 7-position.


Arsenous acid

An arsenic oxoacid consisting of three hydroxy groups attached to a central arsenic atom.


phosphatidylinositol

Any glycerophosphoinositol having one phosphatidyl group esterified to one of the hydroxy groups of inositol.


FYTIC ACID

A myo-inositol hexakisphosphate in which each hydroxy group of myo-inositol is monophosphorylated.


A member of the class of hydroxybiphenyls that is biphenyl carrying a hydroxy group at position 4.


Androsterone

An androstanoid that is 5alpha-androstane having a hydroxy substituent at the 3alpha-position and an oxo group at the 17-position. It is a metabolite of dehydroepiandrosterone .


Bromodichloromethane

A halomethane that is dichloromethane in which oneof the hydrogens has been replaced by a bromine atom. It occurs as a contaminant in drinking water.


N,N-Dimethylaniline

A tertiary amine that is aniline in which the amino hydrogens are replaced by two methyl groups.


Flunitrazepam

A 1,4-benzodiazepinone that is nitrazepam substituted by a methyl group at position 1 and by a fluoro group at position 2'. It is a potent hypnotic, sedative, and amnestic drug used to treat chronic insomnia.


serotonin uptake inhibitor

A compound that specifically inhibits the reuptake of serotonin in the brain. This increases the serotonin concentration in the synaptic cleft which then activates serotonin receptors to a greater extent.


Triazine

Compounds based on a triazine skeleton.


Cirsiliol

A dimethoxyflavone that is flavone substituted by methoxy groups at positions 6 and 7 and hydroxy groups at positions 5, 3' and 4' respectively.


4-Nitrophenyl acetate

A phenyl acetate resulting from the formal condensation of the hydroxy group of 4-nitrophenol with the carboxy group of acetic acid.


A C19-steroid that is testosterone in which the hydrogen at the 16alpha position has been replaced by a hydroxy group.


Bepridil

A tertiary amine in which the substituents on nitrogen are benzyl, phenyl and 3-(2-methylpropoxy)-2-(pyrrolidin-1-yl)propyl.


A macromolecule composed of repeating 2-methylfuran units and terminated with a hydroxy group at the methylene end.


Pentaerythritol 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.


Sterol

Any 3-hydroxy steroid whose skeleton is closely related to cholestan-3-ol (additional carbon atoms may be present in the side chain).


Eupatorin

A trimethoxyflavone that is 6-hydroxyluteolin in which the phenolic hydogens at positions 4', 6 and 7 have been replaced by methyl groups.


Chlorzoxazone

A member of the class of  1,3-benzoxazoles that is 1,3-benzoxazol-2-ol in which the hydrogen atom at position 5 is substituted by chlorine. A centrally acting muscle relaxant with sedative properties, it is used for the symptomatic treatment of painful muscle spasm.


TROSPIUM CHLORIDE

An organic chloride salt of trospium. It is an antispasmodic drug used for the treatment of overactive bladder.


An alpha-diketone that consists of 1-phenylpropane bearing keto substituents at positions 1 and 2. It is found in coffee.


Pentachlorobenzene

A member of the class of pentachlorobenzenes that is benzene in which five of the hydrogens are replaced by chlorines. Now classed as a persistent organic pollutant under the Stockholm Convention.


aromatic compound

A cyclically conjugated molecular entity with a stability (due to delocalization) significantly greater than that of a hypothetical localized structure (e.g. Kekule structure) is said to possess aromatic character.


non-steroidal anti-inflammatory drug

An anti-inflammatory drug that is not a steroid. In addition to anti-inflammatory actions, non-steroidal anti-inflammatory drugs have analgesic, antipyretic, and platelet-inhibitory actions. They act by blocking the synthesis of prostaglandins by inhibiting cyclooxygenase, which converts arachidonic acid to cyclic endoperoxides, precursors of prostaglandins.


A member of the class of 2-nitrophenols that is phenol in which one of the hydrogens that is ortho to the hydroxy group has been replaced by a nitro group.


Carisoprodol

A carbamate ester that is the mono-N-isopropyl derivative of meprobamate (which is a significant metabolite). Carisoprodol  interrupts neuronal communication within the reticular formation and spinal cord, resulting in sedation and alteration in pain perception. It is used as a muscle relaxant in the symptomatic treatment of musculoskeletal conditions associated with painful muscle spasm.


A member of the class of furans that is furan which is substituted at positions 2 and 5 by formyl and hydroxymethyl substituents, respectively. Virtually absent from fresh foods, it is naturally generated in sugar-containing foods during storage, and especially by drying or cooking. It is the causative component in honey that affects the presystemic metabolism and pharmacokinetics of GZ in-vivo.


A member of the class of hydroxybiphenyls that is phenol in which the hydrogen at position 3 has been replaced by a phenyl group.


Resibufogenin

A steroid lactone of Chan su (toad venom), a Chinese medicine obtained from the skin venom gland of toads. A specific Na/K-ATPase protein inhibitor, it is used as a cardiotonic and central nervous system (CNS) respiratory agent, an analgesic and anesthetic, and as a remedy for ulcers.


Methiocarb

A carbamate ester obtained by the formal condensation of the phenolic group of 3,5-dimethyl-4-(methylsulfanyl)phenol with the carboxy group of  methylcarbamic acid.


Phenprocoumon

A hydroxycoumarin that is 4-hydroxycoumarin which is substituted at position 3 by a 1-phenylpropyl group.


A 1,2-diglyceride in which the acyl groups at positions 1 and 2 are specifed as stearoyl and arachidonoyl respectively.


Pregnanolone

The 3alpha-stereoisomer of 3-hydroxy-5beta-pregnan-20-one.


FORMIC ACID

The simplest carboxylic acid, containing a single carbon. Occurs naturally in various sources including the venom of bee and ant stings, and is a useful organic synthetic reagent. Principally used as a preservative and antibacterial agent in livestock feed. Induces severe metabolic acidosis and ocular injury in human subjects.


Succinylcholine

A quaternary ammonium ion that is the bis-choline ester of succinic acid.


steroid

Any of naturally occurring compounds and synthetic analogues, based on the cyclopenta[a]phenanthrene carbon skeleton, partially or completely hydrogenated; there are usually methyl groups at C-10 and C-13, and often an alkyl group at C-17. By extension, one or more bond scissions, ring expansions and/or ring contractions of the skeleton may have occurred. Natural steroids are derived biogenetically from squalene which is a triterpene.


A 2-hexenal in which the olefinic double bond has E configuration. It occurs naturally in a wide range of fruits, vegetables, and spices.


Genkwanin

A monomethoxyflavone that is apigenin in which the hydroxy group at position 7 is methylated.


Benzo[c]phenanthrene

An ortho-fused polycyclic arene resulting from the symmetrical fusion of the C1-C2 bonds of two naphthalene units.


A N-arylpiperazine that is piperazine carrying a 3-chlorophenyl substituent at position 1. It is a metabolite of the antidepressant drug trazodone.


Voriconazole

A triazole-based antifungal agent used for the treatment of esophageal candidiasis, invasive pulmonary aspergillosis, and serious fungal infections caused by Scedosporium apiospermum and Fusarium spp. It is an inhibitor of cytochrome P450 2C9 (CYP2C9) and CYP3A4.


Benzydamine

A member of the class of indazoles carrying benzyl and 3-(dimethylamino)propyl groups at positions 1 and 3 respectively. A locally-acting nonsteroidal anti-inflammatory drug that also exhibits local anaesthetic and analgesic properties.


Tizanidine

2,1,3-Benzothiadiazole substituted at C-4 by a Delta(1)-imidazolin-2-ylamino group and at C-4 by a chloro group.  It is an agonist at alpha2-adrenergic receptor sites.


8-Epi-prostaglandin F2alpha

An isoprostane that is prostaglandin F2alpha having inverted stereochemistry at the 8-position.


Perampanel

A member of the class of bipyridines that is 2,3'-bipyridin-6'-one substituted at positions 1' and 5' by phenyl and 2-cyanophenyl groups respectively. Used as an adjunctive therapy for the treatment of partial-onset seizures in patients with epilepsy.


Benzyl Alcohol

An aromatic alcohol that consists of benzene bearing a single hydroxymethyl substituent.


radical

A molecular entity possessing an unpaired electron.


2-[(1R)-3-(diisopropylamino)-1-phenylpropyl]-4-methylphenol (2R,3R)-2,3-dihydroxybutanedioic acid hydrate


Acenaphthenequinone

An orthoquinone that is the 1,2-dioxo derivative of acenaphthene.


4-Methylumbelliferyl glucoside

A beta-D-glucoside having a 4-methylumbelliferyl substituent at the anomeric position.


An epoxide that is oxirane substituted by a (4-nitrophenoxy)methyl group.


Fenoprofen

A monocarboxylic acid that is propanoic acid in which one of the hydrogens at position 2 is substituted by a 3-phenoxyphenyl group. A non-steroidal anti-inflammatory drug, the dihydrate form of the calcium salt is used for the management of mild to moderate pain and for the relief of pain and inflammation associated with  disorders such as arthritis. It is pharmacologically similar to aspirin, but causes less gastrointestinal bleeding.


Androstenediol

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


Veliparib

A benzimidazole substituted with a carbamoyl group at C-4 and a (2R)-2-methylpyrrolidin-2-yl moiety at C-2.  It is a potent, orally bioavailable PARP inhibitor.


A 4-hydroxy steroid that is estrone substituted by a hydroxy group at position 4.


A  primary arylamine that is aniline in which the hydrogens at the 3- and 4-positions are replaced by methyl groups. A low-melting, crystalline solid, it is used in the production of vitamin B2, dyes, pesticides and other chemicals.


A member of the class of coumarins that is umbelliferone in which the hydroxy group at position 7 is replaced by an ethoxy group.


Pipecolic acid

A piperidinemonocarboxylic acid in which the carboxy group is located at position C-2.


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.


Bromfenac

Amfenac in which the the hydrogen at the 4 position of the benzoyl group is substituted by bromine. It is used for the management of ocular pain and treatment of postoperative inflammation in patients who have undergone cataract extraction. It was withdrawn from the US market in 1998, following concerns over off-label abuse and hepatic failure.


Pyrantel

A carboxamidine that is 1,4,5,6-tetrahydropyrimidine that is substituted at position 1 by a methyl group and at position 2 by an (E)-2-(2-thienyl)vinyl group. It is used, particularly as the embonate [4,4'-methylenebis(3-hydroxy-2-naphthoate)] salt, as an anthelmintic that is effective against intestinal nematodes including threadworms, roundworms and hookworms, and is included in the WHO 'Model List of Essential Medicines'.


Tetrahydropyridine

Any of a class of heterocyclic amines having a saturated five-membered ring.


Nordazepam

A 1,4-benzodiazepinone having phenyl and chloro substituents at positions 5 and 7 respectively; it has anticonvulsant, anxiolytic, muscle relaxant and sedative properties but is used primarily in the treatment of anxiety.


Dihydroxyacetone phosphate

A member of the class of glycerone phosphates that consists of glycerone bearing a single phospho substituent.


A monocarboxylic acid anion resuting from selective deprotonation of the carboxy group of phosphoenolpyruvic acid.


Ergocalciferol

A vitamin D supplement and has been isolated from alfalfa.


A  dihydroxyanthraquinone that is anthracene substituted by hydroxy groups at C-3 and C-7 and oxo groups at C-9 and C-10.


Imidapril

A member of the class of imidazolidines that is (4S)-1-methyl-2-oxoimidazolidine-4-carboxylic acid in which the hydrogen of the imidazolidine nitrogen has been substituted by (1S)-1-{[(2S)-1-ethoxy-1-oxo-4-phenylbutan-2-yl]amino}ethyl group. It is the prodrug for imidaprilat, an ACE inhibitor used for the treatment of chronic heart failure.


Perazine

A phenothiazine derivative in which 10H-phenothiazinecarries a 3-(4-methylpiperazin-1-yl)propyl substituent at the N-10 position.


Disopyramide

A monocarboxylic acid amide that is butanamide substituted by a diisopropylamino group at position 4, a phenyl group at position 2 and a pyridin-2-yl group at position 2. It is used as a  anti-arrhythmia drug.


An androstanoid that is testosterone carrying an additional hydroxy substituent at the 11beta-position.


Pyrimidine

The parent compound of the pyrimidines; a diazine having the two nitrogens at the 1- and 3-positions.


Oxatomide

A member of the class of benzimidazoles that is 1,3-dihydro-2H-benzimidazol-2-one substituted by a 3-[4-(diphenylmethyl)piperazin-1-yl]propyl group at position 1. It is an anti-allergic drug.


A hydroxycoumarin that is coumarin in which the hydrogen at position 4 is replaced by a hydroxy group.


Atomoxetine hydrochloride

The hydrochloride salt of atomoxetine.


4-(Methylsulfanyl)-2-oxobutanoic acid

A 2-oxo monocarboxylic acid derived from L-methionine via the action of methionine transaminase.


Diaziquone

A 1,4-benzoquinone that is substituted at positions 2 and 5 have been replaced by aziridin-1-yl groups and at positions 3 and 6 by (ethoxycarbonyl)amino groups.


Chloromethane

A one-carbon compound that is methane in which one of the hydrogens is replaced by a chloro group.


beta-adrenergic antagonist

An agent that binds to but does not activate beta-adrenergic receptors thereby blocking the actions of endogenous or exogenous beta-adrenergic agonists. beta-Adrenergic antagonists are used for treatment of hypertension, cardiac arrhythmias, angina pectoris, glaucoma, migraine headaches and anxiety.


Fluensulfone

A member of the class of 1,3-thiazoles carrying 3,4,4-trifluorobut-3-ene-1-sulfonyl and chloro substituents at positions 2 and 5 respectively. A nematicide that is effective against a number of plant parasitic nematodes in a range of agricultural and horticultural crops.


An alpha-diketone that is hexane substituted by oxo groups at positions 2 and 3 respectively.


Hexobarbital

A member of the class of barbiturates taht is barbituric acid substituted at N-1 by methyl and at C-5 by methyl and cyclohex-1-enyl groups.


An androstanoid that is androst-5-ene bearing two oxo substituents at positions 3 and 17.


A dichloroaniline carrying chloro substituents at positions 2 and 4.


Any isoprostane derived from the non-enzymatic, free radical oxidation of arachidonic acid.


Nimetazepam

A nitrazepam which is substituted at positions 1 by a methyl group. It is used as an anticonvulsant and as a hypnotic for the short-term management of insomnia.


A 2-hydroxy steroid that is estrone substituted by a hydroxy group at position 2.


statin

Any organooxygen compound whose structure is related to compactin (mevastatin) and which may be used as an anticholesteremic drug due its EC 1.1.1.34/EC 1.1.1.88 (hydroxymethylglutaryl-CoA reductase) inhibitory properties.


10-Formyltetrahydropteroylglutamic acid

A form of tetrahydrofolate that acts as a donor of formyl groups in anabolism. In these reactions 10-formyltetrahydrofolic acid is used as a substrate in formyltransferase reactions, which is important in purine biosynthesis.


An androstanoid that is androstane substituted by oxo groups at positions 3 and 17.


Propargyl alcohol

A terminal acetylenic compound that is prop-2-yne substituted by a hydroxy group at position 1.


N-Nitrosopiperidine

A nitrosamine that is piperidine in which the hydrogen attached to the nitrogen is replaced by a nitroso group. One of the many carcinogens detected in cigarette smoke, it is found in meat, cheese and spices that have been treated with the preservative sodium nitrite.


Oxymetazoline

A member of the class of phenols that is 2,4-dimethylphenol which is substituted at positions 3 and 6 by 4,5-dihydro-1H-imidazol-2-ylmethyl and tert-butyl groups, respectively. A direct-acting sympathomimetic with marked alpha-adrenergic activity, it is a vasoconstrictor that is used (generally as the hydrochloride salt) to relieve nasal congestion.


Prostaglandin

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


Palmitoylcarnitine

An O-acylcarnitine having palmitoyl (hexadecanoyl) as the acyl substituent.


A primary arylamine that is aniline in which the hydrogens at the 2- and 5-positions are replaced by methyl groups. It is used in the manufacture of dyes and other chemicals.


Propafenone

An aromatic ketone that is 3-(propylamino)propane-1,2-diol in which the hydrogen of the primary hydroxy group is replaced by a 2-(3-phenylpropanoyl)phenyl group. It is a class 1C antiarrhythmic drug with local anesthetic effects, and is used as the hydrochloride salt in the management of supraventricular and ventricular arrhythmias.


Diadenosine tetraphosphate

A diadenosyl tetraphosphate compound having the two 5'-adenosyl residues attached at the P(1)- and P(4)-positions.


Huperzine A

A sesquiterpene alkaloid isolated from a club moss Huperzia serrata that has been shown to exhibit neuroprotective activity. It is also an effective inhibitor of acetylcholinesterase and has attracted interest as a therapeutic candidate for Alzheimer's disease.


An 11-oxo steroid that is corticosterone in which the hydroxy substituent at the 11beta position has been oxidised to give the corresponding ketone.


Butyrylthiocholine

A quaternary ammonium ion obtained by the formal condensation of the carboxy group of butyric acid with the thiol group of thiocholine. It is used as a reagent for determination of butyrylcholinesterase activity.


Terbutryn

A methylthio-1,3,5-triazine that is 2-(methylsulfanyl)-1,3,5-triazine substituted by a tert-butylamino and an ethylamino group at positions 2 and 4 respectively.


Benzil

An alpha-diketone that is ethane-1,2-dione substituted by phenyl groups at positions 1 and 2 respectively.


Decanal

A saturated fatty aldehyde formally arising from reduction of the carboxy group of capric acid (decanoic acid).


2-Hydroxyglutaric acid

A 2-hydroxydicarboxylic acid that is glutaric acid in which one hydrogen alpha- to a carboxylic acid group is substituted by a hydroxy group.


A tetrachlorobenzene carrying chloro groups at positions 1, 2, 3 and 5.