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)
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)
来源:Toxin and Toxin Target Database (T3DB)
毒理性
致癌物分类
对人类不具有致癌性(未被国际癌症研究机构IARC列名)。
No indication of carcinogenicity to humans (not listed by IARC).
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)
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)
UV photolysis of small molecules embedded in rare-gas matrices is examined. We demonstrate that photolysis can be self-limited when products absorb the photolysing radiation. As a result of the rising absorption, in-situ detected luminescence of the photolysis product saturates faster than its concentration. In particular, the present study supports the conclusion that 193 nm photolysis of hydrogen-containing
Channeling of Products in the Hot Atom Reaction H + (CN)<sub>2</sub> → HCN/HNC + CN and in the Reaction of CN with CH<sub>3</sub>SH
作者:Brian K. Decker、R. Glen Macdonald
DOI:10.1021/jp0108061
日期:2001.7.1
for the gas-phase hot atom reactionH + (CN)sub 2} yields} HCN/HNC + CN (a) and the reactionCN + CHsub 3}SH yields} HCN/HNC + CHsub 3}S/CHsub 2}SH (b) at 293 K. The reactive H atoms had an initial mean translational energy of 92 kJ mol-1, with a 38 kJ molsup -1} fwhm Gaussian energy distribution. The branching fractions determined for the product channels forming HCN and HNC, respectively, are
Rotational and Vibrational State Distributions of HNC(0 0) from the Hot H Atom Reaction: H + (CN)<sub>2</sub> → HNC + CN
作者:R. Glen Macdonald
DOI:10.1021/jp0010583
日期:2000.11.1
energetic H atoms with a mean translational energy of 92 kJ molsup -1}. The HNC molecule was monitored by time- and frequency-resolved absorption spectroscopy with sub-Doppler resolution. The initial rotational state distribution of each HNC(0 vsup 1}sub 2} 0) vibrationallevel was measured and found to be well-described by a Boltzmann distribution. Only two vibrationallevels were detected so that
Experimental determination of the υ1 fundamental vibrational transition moment for HNC
作者:G. He、R.Glen Macdonald
DOI:10.1016/s0009-2614(98)01445-6
日期:1999.2
generated by the reaction of translationally energetic Hatoms with ClCN, and the resulting products, HCl, HCN and HNC, followed by time-resolved infrared absorption spectroscopy. The subsequent reaction of the Cl and CN species with the Hatom precursor, CH3SH, resulted in a definite stoichiometric relationship between the stable products and HNC. This stoichiometric relationship was used to relate the