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
对人类无致癌性(未列入国际癌症研究机构IARC清单)。
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)
1.周国泰,化学危险品安全技术全书,化学工业出版社,1997 2.国家环保局有毒化学品管理办公室、北京化工研究院合编,化学品毒性法规环境数据手册,中国环境科学出版社.1992 3.Canadian Centre for Occupational Health and Safety,CHEMINFO Database.1998 4.Canadian Centre for Occupational Health and Safety, RTECS Database, 1989
A novel and efficient stereo-controlled synthesis of hexahydroquinolinones via the diene-transmissive hetero-Diels–Alder reaction of cross-conjugated azatrienes with ketenes and electrophilic dienophiles
factors and the electronic demand of the substituents. The second Diels–Alder reaction of the initial [4+2] cycloadducts with electron-deficient dienophiles (TCNE, N-phenylmaleimide) stereoselectively yielded hexahydroquinolinone derivatives. Similarly, a tandem intermolecular–intramolecular mode of the aza-DTHDA reactions produced tetracyclic nitrogen-containing heterocycles in a regio- and stereoselective
Additions of Dibenzyl Selenoxides and Selenonium Ylides to an Electron-Deficient Ethylene and Acetylene
作者:Seizo Tamagaki、Ryuji Akatsuka、Seizi Kozuka
DOI:10.1246/bcsj.50.1641
日期:1977.6
Dibenzyl selenoxides reacted with dimethyl acetylenedicarboxylate and tetracyanoethylene to give new ylides, while the reaction of selenonium ylides produced new ylides or cyclopropane derivatives.
Utilizing two robust C–C bond-forming reactions, the Baylis–Hillman reaction and the Diels–Alder reaction, we report a highly enantio-, regio-, and diastereoselectivesynthesis of hexahydro-2H-chromenes via two sequential [4 + 2] cycloadditions. These tandem and formal cycloadditions have also been performed as a “one-pot” sequence to access the corresponding heterocycles constituting up to five contiguous
Versatile synthesis of bicyclo[4.3.0]nonenes and bicyclo[4.4.0]decenes by a domino Heck-Diels-Alder reaction
作者:Kiah How Ang、Stefan Bräse、Arno G. Steinig、Frank E. Meyer、Amadeu Llebaria、Katharina Voigt、Armin de Meijere
DOI:10.1016/0040-4020(96)00639-4
日期:1996.8
afterwards in a one-pot process) to give bicyclo[4.3.0]nonene and bicyclo[4.4.0]-decene derivatives in good to excellent yields. Among the examples reported are the first cases of intramolecular Heck reactions with a (bromomethylene)cyclopropane starter or/and a methylenecyclopropane terminator which occur without ring opening of the cyclopropyl group.