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Name Description
id 26
T3DB ID T3D0028
Name Cyanide
Class SmallMolecule
Description The cyanide ion consists of a carbon triple bonded to a nitrogen. It readily reacts with hydrogen to form hydrogen cyanide gas, which has a faint almond-like smell. Most people can smell hydrogen cyanide; however, due to an apparent genetic trait, some individuals cannot. Cyanide gas (HCN) can be generated via combustion, including the exhaust of internal combustion engines, tobacco smoke, and especially some plastics derived from acrylonitrile (because of the latter effect, house fires can result in poisonings of the inhabitants). Cyanides are also produced by certain bacteria, fungi, and algae and are found in a number of foods and plants. Small amounts of cyanide can be found in apple seeds, mangoes and bitter almonds. Hydrocyanic acid (a solution of hydrogen cyanide in water) is present in freshly distilled bitter almond oil (2-4%) prior to its removal by precipitation as calcium ferrocyanide to give food quality oil. Hydrogen cyanide and most cyanide salts readily dissolve in water (or other biofluids) and exists in solution as the cyanide ion. Cyanide ions bind to the iron atom of the enzyme cytochrome c oxidase (also known as aa3) in the fourth complex in the mitochondrial membrane in the mitochondria of cells. The binding of cyanide to this cytochrome prevents transport of electrons from cytochrome c oxidase to oxygen. As a result, the electron transport chain is disrupted, meaning that the cell can no longer aerobically produce ATP for energy. Tissues that mainly depend on aerobic respiration, such as the central nervous system and the heart, are particularly affected. Because of its respiratory chain toxicity cyanide has been used as a poison many times throughout history. Its most infamous application was the use of hydrogen cyanide by the Nazi regime in Germany for mass murder in some gas chambers during the Holocaust. Hydrogen cyanide (with the historical common name of Prussic acid) is a colorless and highly volatile liquid that boils slightly above room temperature at 26 °C (78.8 °F). Hydrogen cyanide is weakly acidic and partly ionizes in solution to give the cyanide anion, CN-. The salts of hydrogen cyanide are known as cyanides. HCN is a highly valuable precursor to many chemical compounds ranging from polymers to pharmaceuticals. Hydrogen cyanide is a linear molecule, with a triple bond between carbon and nitrogen. It is a weak acid with a pKa of 9.2. A minor tautomer of HCN is HNC, hydrogen isocyanide.
Categories "Industrial/Workplace Toxin", "Pollutant", "Airborne Pollutant", "Food Toxin", "Natural Toxin"
Types "Organic Compound", "Cyanide Compound", "Nitrile", "Pollutant", "Food Toxin", "Metabolite", "Industrial/Workplace Toxin", "Natural Compound"
Synonyms "Carbon nitride ion", "CN(1-)", "Cyanide ion", "Cyanide(1-) ion", "Cyano", "Cyanure", "Isocyanide", "Nitrile ion", "Nitrodicarbonate", "Prussiate"
CAS Number 05-12-57
Chemical Formula CN
Average Molecular Mass 26.02
Monoisotopic Mass 26.00
IUPAC Name iminomethanide
Traditional Name cyanide
SMILES [C-]#N
InChI Identifier InChI=1S/CN/c1-2/q-1
InChI Key InChIKey=XFXPMWWXUTWYJX-UHFFFAOYSA-N
Kingdom Inorganic Compounds
Super Class Homogeneous Non-metal Compounds
Class Other Non-metal Organides
Sub Class Other non-metal nitrides
Direct Parent Nitriles
Alternate Parents "Inorganic Anions"
Geometric Description Aliphatic Acyclic Compounds
Substituents "Aliphatic Acyclic Compound", "Inorganic Anion", "Other non-metal nitride"
Descriptors "pseudohalide anion (ChEBI)", "a simple group (MetaCyc)"
Status Detected and Quantified
Origin Exogenous
Cellular Locations "Cytoplasm", "Extracellular", "Mitochondria"
Biofluids "Blood", "Urine"
Tissues
Pathways
State Solid
Appearance White powder.
Melting Point
Boiling Point
Solubility
LogP
Route of Exposure Oral (L96) ; inhalation (L96) ; dermal (L96)
Mechanism of Toxicity Organic nitriles decompose into cyanide ions both in vivo and in vitro. Consequently the primary mechanism of toxicity for organic nitriles is their production of toxic cyanide ions or hydrogen cyanide. Cyanide is an inhibitor of cytochrome c oxidase in the fourth complex of the electron transport chain (found in the membrane of the mitochondria of eukaryotic cells). It complexes with the ferric iron atom in this enzyme. The binding of cyanide to this cytochrome prevents transport of electrons from cytochrome c oxidase to oxygen. As a result, the electron transport chain is disrupted and the cell can no longer aerobically produce ATP for energy. Tissues that mainly depend on aerobic respiration, such as the central nervous system and the heart, are particularly affected. Cyanide is also known produce some of its toxic effects by binding to catalase, glutathione peroxidase, methemoglobin, hydroxocobalamin, phosphatase, tyrosinase, ascorbic acid oxidase, xanthine oxidase, succinic dehydrogenase, and Cu/Zn superoxide dismutase. Cyanide binds to the ferric ion of methemoglobin to form inactive cyanmethemoglobin. (L97)
Metabolism Organic nitriles are converted into cyanide ions through the action of cytochrome P450 enzymes in the liver. Cyanide is rapidly absorbed and distributed throughout the body. Cyanide is mainly metabolized into thiocyanate by either rhodanese or 3-mercaptopyruvate sulfur transferase. Cyanide metabolites are excreted in the urine. (L96)
Toxicity
Lethal Dose 200 to 300 mg for an adult human (cyanide salts). (T36)
Carcinogenicity No indication of carcinogenicity to humans (not listed by IARC).
Uses/Sources Cyanide compounds are used in electroplating, metallurgy, organic chemicals production, photographic developing, manufacture of plastics, fumigation of ships, and some mining processes. (L96)
Minimum Risk Level
Health Effects Exposure to high levels of cyanide for a short time harms the brain and heart and can even cause coma, seizures, apnea, cardiac arrest and death. Chronic inhalation of cyanide causes breathing difficulties, chest pain, vomiting, blood changes, headaches, and enlargement of the thyroid gland. Skin contact with cyanide salts can irritate and produce sores. (L96, L97)
Symptoms Cyanide poisoning is identified by rapid, deep breathing and shortness of breath, general weakness, giddiness, headaches, vertigo, confusion, convulsions/seizures and eventually loss of consciousness. (L96, L97)
Treatment Antidotes to cyanide poisoning include hydroxocobalamin and sodium nitrite, which release the cyanide from the cytochrome system, and rhodanase, which is an enzyme occurring naturally in mammals that combines serum cyanide with thiosulfate, producing comparatively harmless thiocyanate. Oxygen therapy can also be administered. (L97)
DrugBank ID
HMDB ID HMDB02084
PubChem Compound ID 5975
ChEMBL ID
ChemSpider ID 5755
KEGG Compound ID C00177
UniProt ID 0
OMIM ID 0
ChEBI ID 17514
BioCyc ID CPD-1074
CTD ID
Stitch ID Cyanide
PDB ID
ACToR ID 6413
Wikipedia Link http://en.wikipedia.org/wiki/Cyanide
Creation Date 2009-03-06 18:57:57
Update Date 2014-12-24 20:20:55