The present study provides the first evidence for in vitro metabolic conversion of a 1,1-disubstituted hydrazine to the corresponding nitrosamine. The study shows that superoxide radical which is generated by NADPH-cytochrome reductase is involved in the oxidation of 1,1-diphenylhydrazine to N-nitrosodiphenylamine catalyzed by rat liver microsomes.
The enzyme systems in rat liver and lung responsible for the oxidative metabolism of hydrazine derivatives were studied to determine whether these enzymes, cytochrome P450 and monoamine oxidase, were responsible for metabolically activating hydrazines to carcinogenic/toxic metabolites. Cytochrome P450 preferentially oxidized the nitrogen to nitrogen bond of 1,2-disubstituted hydrazines and hydrazides, while monoamine oxidase oxidized the nitrogen to nitrogen bond of all the classes of hydrazine derivatives that were tested. Oxidation of the nitrogen to nitrogen bond led to the formation of stable azo intermediates in the case of 1,2-disubstituted hydrazines and to unstable monoazo (diazene) metabolites in the case of monosubstituted hydrazines and hydrazides. /Substituted hydrazines/
By microsomes obtained from bovine ciliary body, 1,1-diphenylhydrazine was oxidized to N-nitrosodiphenylamine in the presence of NADPH. This reaction was stimulated by riboflavin which was recognized to be an electron carrier. The oxidizing activity by microsomes was markedly inhibited by superoxide dismutase, but not by SKF 525-A or carbon monoxide. Similarly, the oxidation of 1,1-diphenylhydrazine to its corresponding nitrosamine occurred in varying degrees when the hydrazine derivative was exposed to visible light in the presence of photosensitizers such as riboflavin, flavin adenine dinucleotide, flavin mononucleotide, lumiflavin, lumichrome, NAD+, NADH, NADP+, or NADPH. The photochemical oxidation was inhibited by active oxygen-scavengers such as superoxide dismutase, L-ascorbic acid or alpha-tocopherol. The superoxide radical involved in the photochemical reaction was determined by measuring the oxidation of epinephrine to adrenochrome. The oxidation of epinephrine was well correlated to that of 1,1-diphenylhydrazine. Thus, the present study provided evidence that the superoxide radical is responsible for the oxidation of a hydrazine derivative to a corresponding nitrosamine by ocular tissue microsomes and by photosensitizers.
The first evidence for the reductive metabolism of a noncyclic nitrosamine to the corresponding hydrazine derivative in vivo and in vitro is provided. Under anaerobic conditions, N-nitrosodiphenylamine was reduced by guinea pig liver 9000 g supernatant to 1,1-diphenylhydrazine in the presence of 2-hydroxypyrimidine or to acetaldehyde diphenylhydrazone in the presence of acetaldehyde. These metabolites were identified unequivocally by comparative study with authentic samples. In addition, the study shows that such reductive reactions of the nitrosamine can be catalyzed by guinea pig and rabbit liver aldehyde oxidase in the presence of its electron donors. When the nitrosamine was given orally to acetaldehyde-treated guinea pigs, a metabolite was detected from plasma and identified as acetaldehyde diphenylhydrazone by comparison with the authentic sample.
来源:Hazardous Substances Data Bank (HSDB)
毒理性
副作用
神经毒素 - 其他中枢神经系统神经毒素
Neurotoxin - Other CNS neurotoxin
来源:Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
Specific treatment for exposure consists of thorough washing of all exposed skin areas with soap and water, copious irrigation of the eyes, and prompt removal of the patient from the source of exposure. /Hydrazines/
After inhalation, observation for progressive respiratory distress is necessary. Chest X-ray and arterial blood gases should be monitored. Administration of oxygen, intubation, and assisted ventilation may become necessary. Pneumonia and bronchitis need to be excluded. /Hydrazines/
Pyridoxine may be antidotal. ...Seizures should be controlled with diazepam, phenytoin, or phenobarbital. Blood sugar levels should be monitored for severe hypoglycemia, which may appear with or without preceding significant hyperglycemia. The patient should be observed for evidence of intravascular hemolysis, methemoglobinemia, and consequent deterioration of renal function. Patients who are symptomatic or who demonstrate a methemoglobin level greater than 30 per cent should be treated with methylene blue 1 to 2 mg per kg slowly IV every 4 hours as needed. Improvement is dramatic if diagnosis is correct. Liver function should be monitored because hydrazines are known hepatotoxins. /Hydrazines/
Elimination is enhanced by forced diuresis and acidification of the urine. Hemodialysis and peritoneal dialysis should be effective, but insufficient human data exist on the use of these modalities. Treatment is otherwise symptomatic and supportive. /Hydrazines/
The reductive singleelectrontransfer (SET) umpolung amination of aldehyde-derived hydrazones has been developed through visible-light-promoted photoredox catalysis. The ideal transformation of hydrazones into the corresponding hydrazonamide through selective carbon–hydrogen (C–H) bond functionalization represents one of the most step- and atom-economical methods. This SET umpolung strategy features
[EN] ELECTRONIC DEVICE INCLUDING A DIAZACHRYSENE DERIVATIVE<br/>[FR] DISPOSITIF ÉLECTRONIQUE COMPRENANT UN DÉRIVÉ DE DIAZACHRYSÈNE
申请人：DU PONT
公开号：WO2014130597A1
公开（公告）日：2014-08-28
There is provided a compound having Formula I. In Formula I: R1-R10 are the same or different and can be H, D, alkyl, aryl, alkoxy, aryloxy, silyl, or deuterated analogs of alkyl, aryl, alkoxy, aryloxy and silyl, where adjacent R groups can be joined together to form a ring; and all other sites are H or D. Additionally in Formula I:(i) at least one of R1-R3 and at least one of R4-R6 is alkyl, alkoxy, silyl, or a deuterated analog, and (ii) at least one of R1-R3 and at least one of R4-R6 is aryl, aryloxy, or a deuterated analog.
CO2 as a C1-building block for the catalytic methylation of amines
作者：Olivier Jacquet、Xavier Frogneux、Christophe Das Neves Gomes、Thibault Cantat
DOI：10.1039/c3sc22240c
日期：——
A novel catalytic reaction has been designed to utilize, for the first time, CO2 as a C1 feedstock in the synthesis of N-methylamines. Simple zinc catalysts, based on commercially available zinc salts and ligands, prove highly efficient in promoting both a 6 electron reduction of carbon dioxide and the formation of a C–N bond, using hydrosilanes and amines.
Résumé New ferrocenyl bishydrazones (2a–2d) have been efficiently obtained from 1,1′-ferrocenedicarboxaldehyde by a straightforward synthesis. The four new compounds have been fully characterized by NMR (1H, 13C), high-resolution mass spectroscopy, and the molecular structure of compounds (2a–2d) has been elucidated by X-ray diffraction on single crystals.
