| Substance | Relationship Strength | Studies | Trials | Classes | Roles |
|---|
ethylene glycol
Ethylene Glycol: A colorless, odorless, viscous dihydroxy alcohol. It has a sweet taste, but is poisonous if ingested. Ethylene glycol is the most important glycol commercially available and is manufactured on a large scale in the United States. It is used as an antifreeze and coolant, in hydraulic fluids, and in the manufacture of low-freezing dynamites and resins.. ethanediol : Any diol that is ethane or substituted ethane carrying two hydroxy groups.. ethylene glycol : A 1,2-glycol compound produced via reaction of ethylene oxide with water. | 2.71 | 3 | 0 | ethanediol;
glycol | metabolite;
mouse metabolite;
solvent;
toxin |
acetone
methyl ketone : A ketone of formula RC(=O)CH3 (R =/= H). | 2 | 1 | 0 | ketone body;
methyl ketone;
propanones;
volatile organic compound | EC 3.5.1.4 (amidase) inhibitor;
human metabolite;
polar aprotic solvent |
benzyl alcohol
Benzyl Alcohol: A colorless liquid with a sharp burning taste and slight odor. It is used as a local anesthetic and to reduce pain associated with LIDOCAINE injection. Also, it is used in the manufacture of other benzyl compounds, as a pharmaceutic aid, and in perfumery and flavoring.. hydroxytoluene : Any member of the class of toluenes carrying one or more hydroxy substituents.. benzyl alcohol : An aromatic alcohol that consists of benzene bearing a single hydroxymethyl substituent.. aromatic alcohol : Any alcohol in which the alcoholic hydroxy group is attached to a carbon which is itself bonded to an aromatic ring.. aromatic primary alcohol : Any primary alcohol in which the alcoholic hydroxy group is attached to a carbon which is itself bonded to an aromatic ring. | 2 | 1 | 0 | benzyl alcohols | antioxidant;
fragrance;
metabolite;
solvent |
dimethyl sulfoxide
Dimethyl Sulfoxide: A highly polar organic liquid, that is used widely as a chemical solvent. Because of its ability to penetrate biological membranes, it is used as a vehicle for topical application of pharmaceuticals. It is also used to protect tissue during CRYOPRESERVATION. Dimethyl sulfoxide shows a range of pharmacological activity including analgesia and anti-inflammation.. dimethyl sulfoxide : A 2-carbon sulfoxide in which the sulfur atom has two methyl substituents. | 2.41 | 2 | 0 | sulfoxide;
volatile organic compound | alkylating agent;
antidote;
Escherichia coli metabolite;
geroprotector;
MRI contrast agent;
non-narcotic analgesic;
polar aprotic solvent;
radical scavenger |
formaldehyde
paraform: polymerized formaldehyde; RN given refers to parent cpd; used in root canal therapy | 2.13 | 1 | 0 | aldehyde;
one-carbon compound | allergen;
carcinogenic agent;
disinfectant;
EC 3.5.1.4 (amidase) inhibitor;
environmental contaminant;
Escherichia coli metabolite;
mouse metabolite;
Saccharomyces cerevisiae metabolite |
glycerol
Moon: The natural satellite of the planet Earth. It includes the lunar cycles or phases, the lunar month, lunar landscapes, geography, and soil. | 2.04 | 1 | 0 | alditol;
triol | algal metabolite;
detergent;
Escherichia coli metabolite;
geroprotector;
human metabolite;
mouse metabolite;
osmolyte;
Saccharomyces cerevisiae metabolite;
solvent |
hydrogen cyanide
Hydrogen Cyanide: Hydrogen cyanide (HCN); A toxic liquid or colorless gas. It is found in the smoke of various tobacco products and released by combustion of nitrogen-containing organic materials.. hydrogen cyanide : A one-carbon compound consisting of a methine group triple bonded to a nitrogen atom | 2.02 | 1 | 0 | hydracid;
one-carbon compound | Escherichia coli metabolite;
human metabolite;
poison |
hydrogen
Hydrogen: The first chemical element in the periodic table with atomic symbol H, and atomic number 1. Protium (atomic weight 1) is by far the most common hydrogen isotope. Hydrogen also exists as the stable isotope DEUTERIUM (atomic weight 2) and the radioactive isotope TRITIUM (atomic weight 3). Hydrogen forms into a diatomic molecule at room temperature and appears as a highly flammable colorless and odorless gas.. dihydrogen : An elemental molecule consisting of two hydrogens joined by a single bond. | 2.49 | 2 | 0 | elemental hydrogen;
elemental molecule;
gas molecular entity | antioxidant;
electron donor;
food packaging gas;
fuel;
human metabolite |
iodine
Iodine: A nonmetallic element of the halogen group that is represented by the atomic symbol I, atomic number 53, and atomic weight of 126.90. It is a nutritionally essential element, especially important in thyroid hormone synthesis. In solution, it has anti-infective properties and is used topically.. diiodine : Molecule comprising two covalently bonded iodine atoms with overall zero charge.. | 2.13 | 1 | 0 | diatomic iodine | nutrient |
methanol
Methanol: A colorless, flammable liquid used in the manufacture of FORMALDEHYDE and ACETIC ACID, in chemical synthesis, antifreeze, and as a solvent. Ingestion of methanol is toxic and may cause blindness.. primary alcohol : A primary alcohol is a compound in which a hydroxy group, -OH, is attached to a saturated carbon atom which has either three hydrogen atoms attached to it or only one other carbon atom and two hydrogen atoms attached to it.. methanol : The primary alcohol that is the simplest aliphatic alcohol, comprising a methyl and an alcohol group. | 2.03 | 1 | 0 | alkyl alcohol;
one-carbon compound;
primary alcohol;
volatile organic compound | amphiprotic solvent;
Escherichia coli metabolite;
fuel;
human metabolite;
mouse metabolite;
Mycoplasma genitalium metabolite |
1-octanol
1-Octanol: A colorless, slightly viscous liquid used as a defoaming or wetting agent. It is also used as a solvent for protective coatings, waxes, and oils, and as a raw material for plasticizers. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed). octan-1-ol : An octanol carrying the hydroxy group at position 1. | 2.06 | 1 | 0 | octanol;
primary alcohol | antifungal agent;
bacterial metabolite;
fuel additive;
kairomone;
plant metabolite |
pyridoxal phosphate
Pyridoxal Phosphate: This is the active form of VITAMIN B 6 serving as a coenzyme for synthesis of amino acids, neurotransmitters (serotonin, norepinephrine), sphingolipids, aminolevulinic acid. During transamination of amino acids, pyridoxal phosphate is transiently converted into pyridoxamine phosphate (PYRIDOXAMINE).. pyridoxal 5'-phosphate : The monophosphate ester obtained by condensation of phosphoric acid with the primary hydroxy group of pyridoxal. | 1.96 | 1 | 0 | methylpyridines;
monohydroxypyridine;
pyridinecarbaldehyde;
vitamin B6 phosphate | coenzyme;
cofactor;
EC 2.7.7.7 (DNA-directed DNA polymerase) inhibitor;
Escherichia coli metabolite;
human metabolite;
mouse metabolite;
Saccharomyces cerevisiae metabolite |
1-anilino-8-naphthalenesulfonate
1-anilino-8-naphthalenesulfonate: RN given refers to parent cpd. 8-anilinonaphthalene-1-sulfonic acid : A naphthalenesulfonic acid that is naphthalene-1-sulfonic acid substituted by a phenylamino group at position 8. | 2.74 | 3 | 0 | aminonaphthalene;
naphthalenesulfonic acid | fluorescent probe |
ether
Ether: A mobile, very volatile, highly flammable liquid used as an inhalation anesthetic and as a solvent for waxes, fats, oils, perfumes, alkaloids, and gums. It is mildly irritating to skin and mucous membranes.. ether : An organooxygen compound with formula ROR, where R is not hydrogen.. diethyl ether : An ether in which the oxygen atom is linked to two ethyl groups. | 2.71 | 3 | 0 | ether;
volatile organic compound | inhalation anaesthetic;
non-polar solvent;
refrigerant |
2-propanol
2-Propanol: An isomer of 1-PROPANOL. It is a colorless liquid having disinfectant properties. It is used in the manufacture of acetone and its derivatives and as a solvent. Topically, it is used as an antiseptic.. propan-2-ol : A secondary alcohol that is propane in which one of the hydrogens attached to the central carbon is substituted by a hydroxy group. | 2.42 | 2 | 0 | secondary alcohol;
secondary fatty alcohol | protic solvent |
stearic acid
octadecanoic acid : A C18 straight-chain saturated fatty acid component of many animal and vegetable lipids. As well as in the diet, it is used in hardening soaps, softening plastics and in making cosmetics, candles and plastics. | 2.03 | 1 | 0 | long-chain fatty acid;
saturated fatty acid;
straight-chain saturated fatty acid | algal metabolite;
Daphnia magna metabolite;
human metabolite;
plant metabolite |
carbon tetrachloride
Carbon Tetrachloride: A solvent for oils, fats, lacquers, varnishes, rubber waxes, and resins, and a starting material in the manufacturing of organic compounds. Poisoning by inhalation, ingestion or skin absorption is possible and may be fatal. (Merck Index, 11th ed). tetrachloromethane : A chlorocarbon that is methane in which all the hydrogens have been replaced by chloro groups. | 2.02 | 1 | 0 | chlorocarbon;
chloromethanes | hepatotoxic agent;
refrigerant |
lactose
Lactose: A disaccharide of GLUCOSE and GALACTOSE in human and cow milk. It is used in pharmacy for tablets, in medicine as a nutrient, and in industry.. lactose : A glycosylglucose disaccharide, found most notably in milk, that consists of D-galactose and D-glucose fragments bonded through a beta-1->4 glycosidic linkage. The glucose fragment can be in either the alpha- or beta-pyranose form, whereas the galactose fragment can only have the beta-pyranose form.. beta-lactose : The beta-anomer of lactose. | 2.06 | 1 | 0 | lactose | |
1,2-dipalmitoylphosphatidylcholine
1,2-Dipalmitoylphosphatidylcholine: Synthetic phospholipid used in liposomes and lipid bilayers to study biological membranes. It is also a major constituent of PULMONARY SURFACTANTS. | 2.07 | 1 | 0 | | |
dimethylformamide
Dimethylformamide: A formamide in which the amino hydrogens are replaced by methyl groups.. N,N-dimethylformamide : A member of the class of formamides that is formamide in which the amino hydrogens are replaced by methyl groups. | 2.44 | 2 | 0 | formamides;
volatile organic compound | geroprotector;
hepatotoxic agent;
polar aprotic solvent |
propane
Propane: A three carbon alkane with the formula H3CCH2CH3. | 7.07 | 1 | 0 | alkane;
gas molecular entity | food propellant |
isoprene
isoprene: used in manufacture of ''synthetic'' rubber, butyl rubber; copolymer in production of elastomers; structure. isoprene : A hemiterpene with the formula CH2=C(CH3)CH=CH2; the monomer of natural rubber and a common structure motif to the isoprenoids, a large class of other naturally occurring compounds. | 1.97 | 1 | 0 | alkadiene;
hemiterpene;
volatile organic compound | plant metabolite |
pyromellitic dianhydride
[no description available] | 2.06 | 1 | 0 | | |
furaldehyde
Furaldehyde: A heterocyclic compound consisting of a furan where the hydrogen at position 2 is substituted by a formyl group.. furfural : An aldehyde that is furan with the hydrogen at position 2 substituted by a formyl group. | 2.13 | 1 | 0 | aldehyde;
furans | Maillard reaction product;
metabolite |
tert-butylbenzene
[no description available] | 2.06 | 1 | 0 | | |
4,4'-diphenylmethane diisocyanate
4,4'-diphenylmethane diisocyanate: used as a hardening agent incorporated in polyurethanes. diphenylmethane-4,4'-diisocyanate : A diisocyanate consisting of diphenylmethane with two isocyanate groups at the 4- and 4'-positions. | 1.99 | 1 | 0 | diisocyanate | allergen;
hapten |
methyl isobutyl ketone
[no description available] | 2.13 | 1 | 0 | ketone | |
cyclohexanol
Cyclohexanols: Monohydroxy derivatives of cyclohexanes that contain the general formula R-C6H11O. They have a camphorlike odor and are used in making soaps, insecticides, germicides, dry cleaning, and plasticizers.. cyclohexanols : An alcohol in which one or more hydroxy groups are attached to a cyclohexane skeleton. | 2 | 1 | 0 | cyclohexanols;
secondary alcohol | solvent |
pentane
Pentanes: Five-carbon saturated hydrocarbon group of the methane series. Include isomers and derivatives.. pentane : A straight chain alkane consisting of 5 carbon atoms. | 2 | 1 | 0 | alkane;
volatile organic compound | non-polar solvent;
refrigerant |
methyl cellosolve
methyl cellosolve: widely used industrial solvent for resins, lacquers, dyes & inks; may cause anemia macrocytosis, appearance of young granulocytes in blood; RN given refers to parent cpd | 4.18 | 5 | 0 | glycol ether | protic solvent;
solvent |
dimethoxymethane
dimethoxymethane : An acetal that is the dimethyl acetal derivative of formaldehyde. | 7.1 | 1 | 0 | acetal;
diether | |
tetrahydrofuran
oxolane : A cyclic ether that is butane in which one hydrogen from each methyl group is substituted by an oxygen. | 7.05 | 1 | 0 | cyclic ether;
oxolanes;
saturated organic heteromonocyclic parent;
volatile organic compound | polar aprotic solvent |
2,5-hexanedione
2,5-hexanedione: metabolite of methyl-n-butyl ketone. 2,5-hexanedione : A diketone that is hexane substituted by oxo groups at positions 2 and 5. It is a toxic metabolite of hexane and of 2-hexanone | 2 | 1 | 0 | diketone;
methyl ketone | human xenobiotic metabolite;
neurotoxin |
2-ethoxyethanol
2-ethoxyethanol : A hydroxyether that is the ethyl ether derivative of ethylene glycol. | 3.06 | 1 | 0 | glycol ether;
primary alcohol | protic solvent;
teratogenic agent |
1,5-pentanediol
[no description available] | 2 | 1 | 0 | primary alcohol | |
diethylene glycol
glycol ether : A hydroxyether which contains both an ether and alcohol functional groups. It is one of the most versatile classes of organic solvents which are commonly used in paints, cleaners, adhesives, pharmaceuticals and cosmetics. | 2.06 | 1 | 0 | hydroxyether | |
diglyme
diglyme : A polyether that is the dimethyl ether derivative of diethylene glycol. | 1.97 | 1 | 0 | polyether | environmental contaminant;
solvent;
xenobiotic |
triglyme
triglyme : A polyether that consists of dodecane in which the carbon atoms at positions 2, 5, 8 and 11 are replaced by oxygen atoms. | 1.97 | 1 | 0 | polyether | solvent |
n-heptane
Heptanes: Seven-carbon alkanes with the formula C7H16.. heptane : A straight-chain alkane with seven carbon atoms. It has been found in Jeffrey pine (Pinus jeffreyi). | 2.07 | 1 | 0 | alkane;
volatile organic compound | non-polar solvent;
plant metabolite |
indazoles
Indazoles: A group of heterocyclic aromatic organic compounds consisting of the fusion of BENZENE and PYRAZOLES. | 2.13 | 1 | 0 | indazole | |
1,3-propanediol
propane-1,3-diol : The simplest member of the class of propane-1,3-diols, consisting of propane in which one hydrogen from each methyl group is substituted by a hydroxy group. A colourless, viscous, water-miscible liquid with a high (210degreeC) boiling point, it is used in the synthesis of certain polymers and as a solvent and antifreeze. | 2.04 | 1 | 0 | propane-1,3-diols | metabolite;
protic solvent |
malachite green
malachite green: RN given refers to parent cpd; structure. malachite green : An organic chloride salt that is the monochloride salt of malachite green cation. Used as a green-coloured dye, as a counter-stain in histology, and for its anti-fungal properties in aquaculture. | 1.99 | 1 | 0 | organic chloride salt | antibacterial agent;
antifungal drug;
carcinogenic agent;
environmental contaminant;
fluorochrome;
histological dye;
teratogenic agent |
methyl n-butyl ketone
Methyl n-Butyl Ketone: An industrial solvent which causes nervous system degeneration. MBK is an acronym often used to refer to it.. hexanone : A ketone that is a hexane carrying an oxo substituent at unspecified position. | 2.13 | 1 | 0 | ketone | |
methoxyacetic acid
methoxyacetic acid: RN given refers to parent cpd. methoxyacetic acid : A monocarboxylic acid that is acetic acid in which one of the methyl hydrogens is replaced by a methoxy group. | 2.02 | 1 | 0 | ether;
monocarboxylic acid | antineoplastic agent;
apoptosis inducer;
human xenobiotic metabolite;
mutagen |
ethylene glycol diethyl ether
[no description available] | 2.01 | 1 | 0 | | |
c.i. 42510
Rosaniline Dyes: Compounds that contain the triphenylmethane aniline structure found in rosaniline. Many of them have a characteristic magenta color and are used as COLORING AGENTS.. basic fuchsin : A four-component mixture of chemically related dyes comprising pararosanilin, rosanilin, magenta II and new fuchsin in varying amounts. rosanilin : A hydrochloride that is the monohydrochloride of 4-[(4-aminophenyl)(4-iminocyclohexa-2,5-dien-1-ylidene)methyl]-2-methylaniline. One of the major constituents of Basic fuchsin, together with pararosanilin, magenta II and new fuchsin. | 1.99 | 1 | 0 | | |
stavudine
Stavudine: A dideoxynucleoside analog that inhibits reverse transcriptase and has in vitro activity against HIV.. stavudine : A nucleoside analogue obtained by formal dehydration across positions 2 and 3 of thymidine. An inhibitor of HIV-1 reverse transcriptase | 2.03 | 1 | 0 | dihydrofuran;
nucleoside analogue;
organic molecular entity | antimetabolite;
antiviral agent;
EC 2.7.7.49 (RNA-directed DNA polymerase) inhibitor |
molybdenum
Molybdenum: A metallic element with the atomic symbol Mo, atomic number 42, and atomic weight 95.95. It is an essential trace element, being a component of the enzymes xanthine oxidase, aldehyde oxidase, and nitrate reductase. | 2.07 | 1 | 0 | chromium group element atom | micronutrient |
palladium
Palladium: A chemical element having an atomic weight of 106.4, atomic number of 46, and the symbol Pd. It is a white, ductile metal resembling platinum, and following it in abundance and importance of applications. It is used in dentistry in the form of gold, silver, and copper alloys.. palladium : Chemical element (nickel group element atom) with atomic number 46. | 7.83 | 3 | 0 | metal allergen;
nickel group element atom;
platinum group metal atom | |
iodine
[no description available] | 2.41 | 1 | 0 | halide anion;
monoatomic iodine | human metabolite |
phenyl acetate
phenyl acetate: The ester formed between phenol and acetic acid. Don't confuse with phenylacetic acid derivatives listed under PHENYLACETATES.. phenyl acetate : An acetate ester obtained by the formal condensation of phenol with acetic acid. | 2.02 | 1 | 0 | benzenes;
phenyl acetates | |
1,4-dioxane
1,4-dioxane: dehydrating agent; polar solvent miscible both with water & most organic solvents. dioxane : Any member of the class of dioxanes that is a cyclohexane in which two carbon atoms are replaced by oxygen atoms.. 1,4-dioxane : A dioxane with oxygen atoms at positions 1 and 4. | 2.46 | 2 | 0 | dioxane;
volatile organic compound | carcinogenic agent;
metabolite;
NMR chemical shift reference compound;
non-polar solvent |
vanadates
Vanadates: Oxyvanadium ions in various states of oxidation. They act primarily as ion transport inhibitors due to their inhibition of Na(+)-, K(+)-, and Ca(+)-ATPase transport systems. They also have insulin-like action, positive inotropic action on cardiac ventricular muscle, and other metabolic effects.. vanadate(3-) : A vanadium oxoanion that is a trianion with formula VO4 in which the vanadium is in the +5 oxidation state and is attached to four oxygen atoms. | 2.15 | 1 | 0 | trivalent inorganic anion;
vanadium oxoanion | EC 3.1.3.1 (alkaline phosphatase) inhibitor;
EC 3.1.3.16 (phosphoprotein phosphatase) inhibitor;
EC 3.1.3.41 (4-nitrophenylphosphatase) inhibitor;
EC 3.1.3.48 (protein-tyrosine-phosphatase) inhibitor |
glucose, (beta-d)-isomer
beta-D-glucose : D-Glucopyranose with beta configuration at the anomeric centre.. (1->4)-beta-D-glucan : A beta-D-glucan in which the glucose units are connected by (1->4) linkages.. (1->3)-beta-D-glucan : A beta-D-glucan in which the glucose units are connected by (1->3) linkages. | 2 | 1 | 0 | D-glucopyranose | epitope;
mouse metabolite |
trimethylsilyl iodide
trimethylsilyl iodide: structure in first source | 2.41 | 1 | 0 | | |
cyanates
Cyanates: Organic salts of cyanic acid containing the -OCN radical.. cyanates : Salts and esters of cyanic acid, HOC#N; compounds carrying the cyanate functional group -O-C#N.. isocyanates : Organonitrogen compounds that are derivatives of isocyanic acid; compounds containing the isocyanate functional group -N=C=O (as opposed to the cyanate group, -O-C#N). | 1.99 | 1 | 0 | | |
5-hydroxymethylfurfural
5-hydroxymethylfurfural: has antisickling activity; HMF is the causative component in honey that affects the presystemic metabolism and pharmacokinetics of GZ in-vivo. 5-hydroxymethylfurfural : 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. | 2.13 | 1 | 0 | arenecarbaldehyde;
furans;
primary alcohol | indicator;
Maillard reaction product |
sodium sulfide
sodium sulfide: see also record for sodium bisulfide; actisoufre is the sodium sulfide component of sulfur-containing thermal springs which is also found in Saccharomyces cerevisiae | 2.15 | 1 | 0 | | |
sodium ethoxide
sodium ethoxide : An organic monosodium salt that has ethoxide as the counterion. | 2.15 | 1 | 0 | organic sodium salt | nucleophilic reagent |
ranitidine
Ranitidine: A non-imidazole blocker of those histamine receptors that mediate gastric secretion (H2 receptors). It is used to treat gastrointestinal ulcers.. ranitidine : A member of the class of furans used to treat peptic ulcer disease (PUD) and gastroesophageal reflux disease. | 2.03 | 1 | 0 | C-nitro compound;
furans;
organic sulfide;
tertiary amino compound | anti-ulcer drug;
drug allergen;
environmental contaminant;
H2-receptor antagonist;
xenobiotic |
lithium
Lithium: An element in the alkali metals family. It has the atomic symbol Li, atomic number 3, and atomic weight [6.938; 6.997]. Salts of lithium are used in treating BIPOLAR DISORDER. | 7.05 | 1 | 0 | alkali metal atom | |
ferrocenium
ferrocenium: structure given in first source | 2.07 | 1 | 0 | | |
hymecromone
Hymecromone: A coumarin derivative possessing properties as a spasmolytic, choleretic and light-protective agent. It is also used in ANALYTICAL CHEMISTRY TECHNIQUES for the determination of NITRIC ACID. | 2.01 | 1 | 0 | hydroxycoumarin | antineoplastic agent;
hyaluronic acid synthesis inhibitor |
phosphorus
Phosphorus: A non-metal element that has the atomic symbol P, atomic number 15, and atomic weight 31. It is an essential element that takes part in a broad variety of biochemical reactions. | 1.99 | 1 | 0 | monoatomic phosphorus;
nonmetal atom;
pnictogen | macronutrient |
oligonucleotides
[no description available] | 2.04 | 1 | 0 | | |
cellulose
DEAE-Cellulose: Cellulose derivative used in chromatography, as ion-exchange material, and for various industrial applications. | 2.13 | 1 | 0 | glycoside | |
octyl galactopyranoside
octyl galactopyranoside: the minimum acceptor-substrate for H transferase; structure in first source | 2.06 | 1 | 0 | | |
4-hydroxyquinazoline
4-oxo-3,4-dihydroquinazoline: structure in first source | 2.13 | 1 | 0 | quinazolines | |
vicine
vicine: pyrimidine glycoside found in fava bean; structure | 2 | 1 | 0 | glycoside | |
pyrimidinones
Pyrimidinones: Heterocyclic compounds known as 2-pyrimidones (or 2-hydroxypyrimidines) and 4-pyrimidones (or 4-hydroxypyrimidines) with the general formula C4H4N2O. | 2 | 1 | 0 | | |