Vinyl chloride is primarily and rapidly metabolized in the liver, and this metabolism is saturable. ...The first step in the metabolism of vinyl chloride is oxidation, which is predominantly mediated by human cytochrome P450 (CYP) 2E1, to form the highly reactive chloroethylene oxide, which can spontaneously rearrange to chloroacetaldehyde. ... Conjugation of chloroethylene oxide and chloroacetaldehyde with glutathione (GSH) eventually leads to the major urinary metabolites N-acetyl-S-(2-hydroxyethyl)cysteine and thiodiglycolic acid. Chloroethylene oxide and chloroacetaldehyde can also be detoxified to glycolaldehyde by microsomal epoxide hydrolase (mEH) and to the urinary metabolite chloroacetic acid by aldehyde dehydrogenase 2 (ALDH2), respectively.
Following oral administration of (14)C-vinyl chloride, (14)C-carbon dioxide, (14)C-labelled urea and glutamic acid were identified as minor metabolites.
After inhalation of (14)C vinyl chloride by rats ... three urinary metabolites have been detected: N-acetyl-S-(2-hydroxyethyl)cysteine, thiodiglycolic acid, and an unidentified substance.
The principal (14)C urinary metabolites of orally administered (14)C-vinyl chloride, in the male rat, are N-acetyl-S-(2 hydroxyethyl)cysteine, N-acetyl-S-vinylcysteine and thiodiglycollic acid and lesser amounts of urea, glutamic acid, chloracetic acid and traces of methione and serine. The proportions of the three major urinary metabolites in the rat appear to be unaffected by either the dose, or the route of administration.
来源:Hazardous Substances Data Bank (HSDB)
代谢
氯乙烯的人类已知代谢物包括2-氯环氧乙烷。
VINYL CHLORIDE has known human metabolites that include 2-Chlorooxirane.
IDENTIFICATION AND USE: Vinyl chloride is a colorless gas or liquid (below 77 degrees F). It is used in the plastics industry to manufacture polyvinyl chloride, and in organic syntheses. It has been used as refrigerant and spray can propellant. HUMAN STUDIES: Vinyl chloride causes angiosarcoma of the liver, and hepatocellular carcinoma. Past occupational exposure to several hundred ppm of vinyl chloride for periods ranging from one month to 3 years has been associated with development of "vinyl chloride disease". Vinyl chloride disease is characterized by acroosteolysis, a condition characterized by lytic lesions of bones (primarily of fingers), scleroderma of the connective tissue in the fingers with dermal thickening, and a Raynaud-like condition with reversible arteriole constriction causing numbness, pallor and cyanosis of the fingers. The attribution of acroosteolysis to vinyl chloride exposure is based almost entirely on case reports and has been estimated to affect <3% of workers involved in the polymerization of vinyl chloride. In patients with chronic occupational exposure, neurological disturbances include sensory-motor polyneuropathy, trigeminal sensory neuropathy, slight pyramidal signs and cerebellar and extrapyramidal motor disorders. Psychiatric disturbances included neurasthenic or depressive syndromes. Sleeplessness and loss of sexual functions were frequently encountered. Pathological EEG alterations were found in a high proportion of patients. A chronic hepatic disorder of porphyrin metabolism was found in 36 workers with vinyl chloride-induced hepatic injury following long-time industrial exposure. Pathologic porphyrinuria, especially secondary coproporphyrinuria with transition to subclinical chronic hepatic porphyria, is a consistent pathobiochemical parameter for the recognition of vinyl chloride hepatic lesions. The major immunological abnormalities reported in vinyl chloride disease patients include hyperimmunoglobulinemia with a polyclonal increase in IgG, cryoglobulinemia, cryofibrinogenemia, and in vivo activation of complement. Vinyl chloride is an occupational carcinogen which caused micronuclei in human cells. There was significant increase in chromosomal abnormalities in cultured peripheral lymphocytes from 57 male workers when compared with controls. Sister chromatid exchange was the more sensitive endpoint for indicating a biological response. ANIMAL STUDIES: Brief (30 minutes) exposures to concentrations of vinyl chloride ranging from 100,000 to 400,000 ppm have been shown to be fatal in rats, guinea pigs and mice. Symptoms of intoxication in rats and mice include muscular incoordination and twitching, CNS depression and respiratory failure. Intense salivation and lacrimation have been noted in rats, guinea pigs and rabbits exposed acutely to high concentrations (375-700 mg/L) of vinyl chloride gas. When placed on skin or in eyes, liquid vinyl chloride may freeze tissue and produce a chemical burn as it evaporates, causing damage to the underlying tissue. Profound CNS depression was reported in guinea-pigs exposed to vinyl chloride at 65,000 mg/cu m for 90 min. Ataxia was observed at this dose level after 5 min of exposure. The anesthetic action of vinyl chloride was also observed in dogs and mice. Investigators reported deep CNS depression in rats and mice exposed to 260,000 mg/cu m for 30 min. The CNS depressant effect was preceded by increased motor activity after 5 min of exposure, twitching of extremities (after 10 min), ataxia (after 15 min) and tremor (after 15 min). Rats exposed to 130,000 mg/cu m for 60 min showed ataxia preceded by hyperactivity but no /CNS depressant/ effect. Forty rabbits were exposed for 4 hours/day on 5 days/week for 12 months to air containing (10,000 ppm) vinyl chloride. Between 9 and 15 months exposure, 12 skin acanthomas and 6 lung adenocarcinomas were seen. No similar tumors occurred in 20 controls after 15 months observation. Rats were exposed to 10,000 ppm vinyl chloride in air for 4 hours/day on 5 days/week for 5 weeks, starting at the age of 13 weeks (120 rats per group) or 1 day (43 and 46 rats). Animals were observed for 135 weeks. One hepatoma was reported in the older rats in newborn rats, 10 angiosarcomas and 15 hepatomas were found. No liver tumors were reported in 249 controls. Vinyl chloride was administered for 7 hr/day on days 6-18 of gestation in mice, rats, and rabbits. It was concluded that although maternal toxicity observed, vinyl chloride alone did not cause significant embryonal or fetal toxicity and was not teratogenic in any of the species at concentrations tested. Vinyl chloride produced a significant increase in the frequency of recessive lethal mutations in male Drosophila melangaster. Mutagenic activity of vinyl chloride was reported in yeast (S. pombe and S. cerevisiae) in the presence of metabolic activation. Vinyl chloride was mutagenic to S. pombe in the "host mediated" assay when mice were treated with an oral dose of 700 mg/kg of vinyl chloride. Using Salmonella tester strains, direct mutagenicity of vinyl chloride was reported at 20% (v/v) in air (200,000 ppm) in the absence of metabolic activation. Mutagenic response was increased by metabolic activation. However, 20% vinyl chloride (v/v in air) was inactive in systems employing S. typhimurium strains TA1536, TA1537 and TA1538. ECOTOXICITY STUDIES: In Daphnia magna exposure, results indicated impacts of vinyl chloride on the regulation of genes related to glutathione-S-transferase (GST), juvenile hormone esterase (JHE), and the vitelline outer layer membrane protein (VMO1).
Vinyl chloride poisoning exhibits many of the characteristics of autoimmune diseases. This is believed to be the result of a reactive vinyl chloride intermediate metabolite binding to an immunoglobulin, altering the protein and initiating an immune response. The metabolites of vinyl chloride, especially choloroethylene oxide, are mutagenic and act by covalently binding to DNA. This produces cyclic etheno-adducts, which cause base-pair transitions during transcription and DNA crosslinks. Metabolites also may cause oxidative stress and affecting tumor supressor genes, as vinyl chloride has been known to produce specific mutations in the p53 and Ki-ras genes. Vinyl chloride metabolites are also believed to exert toxic effects in the liver by covalently binding to liver proteins, resulting in cellular toxicity. (L3, A65)
There is sufficient evidence in humans for the carcinogenicity of vinyl chloride. Vinyl chloride causes angiosarcoma of the liver, and hepatocellular carcinoma. There is sufficient evidence in experimental animals for the carcinogenicity of vinyl chloride. Vinyl chloride is carcinogenic to humans (Group 1).
On the basis of sufficient evidence for carcinogenicity in human epidemiology studies, vinyl chloride is considered to best fit the weight-of-evidence characterization Category A, according to current EPA Risk Assessment Guidelines (USEPA, 1986).
Vinyl chloride dissolved in either oil or water when administered to rats by gavage, was absorbed extremely rapidly. Peak blood serum concentrations of vinyl chloride were observed within 10 minutes of dosing.
Pulmonary absorption of vinyl chloride in humans appeared to be rapid and the percentage absorbed was independent of the concentration inhaled. ... Adult male volunteers exposed for 6 hr to 2.9, 5.8, 11.6 or 23.1 ppm (7.5, 15, 30 or 60 mg/cu m) by gas mask retained on average approximately 42% of inhaled vinyl chloride. Pulmonary uptake is determined in part by the blood:air partition coefficient, which is 1.16 for vinyl chloride.
Animal data have demonstrated that pulmonary and gastrointestinal absorption of vinyl chloride occurs readily and rapidly. On the contrary, dermal absorption of airborne vinyl chloride is probably not significant. In monkeys, ... only 0.023-0.031% of the total available vinyl chloride was absorbed by the dermal route, whereas absorption in rats was virtually complete following single oral doses (44-92 mg/kg bw) of vinyl chloride in aqueous solution. When rats were exposed to initial concentrations of < 260 mg/cu m (100 ppm), about 40% of inhaled (14)C-vinyl chloride was absorbed by the lung.
The main routes of elimination of vinyl chloride and its metabolites are exhalation and urinary excretion, respectively. Accordingly, thiodiglycolic acid has been reported to be the major metabolite of vinyl chloride detected in the urine of exposed workers. Urinary levels of thiodiglycolic acid were correlated with levels of vinyl chloride in the air at concentrations of > 5 ppm.
Photo-degradation of yperite over V, Fe and Mn-doped titania–silica photocatalysts
作者:Ştefan Neaţu、Vasile I. Pârvulescu、Gabriel Epure、Emilia Preda、Vasile Şomoghi、Alessandro Damin、Silvia Bordiga、Adriano Zecchina
DOI:10.1039/b810200g
日期:——
The photocatalytic decomposition of yperite (bis(2-chloroethyl)sulfide), a chemical warfare agent, was achieved by using titaniaâsilica catalysts doped with several transition metal ions. The preparation of these catalysts was achieved by impregnation of a titaniaâsilica mixed oxide previously synthesized using a sol-gel route with salts of the doping elements (vanadium, iron, manganese). The above catalysts were characterized using several spectroscopic techniques: FTIR, Raman, DR-UV-Vis, and XPS. The band gap energy was measured for each photocatalytic system. The reaction was carried out in two different types of reactors, i.e. naturally aerated and a closed quartz tube aerated under a constant flow, and using two types of irradiation, UV-Vis and Vis. The investigated systems proved to be extremely active, leading to an almost complete degradation of yperite in 2 h of irradiation. An excellent correlation between the photocatalytic performances and the band gap has been found. Based on the characterization data and on the temporal evolution of the reaction products, a reaction mechanism has been suggested. This mechanism considers two distinct pathways for the decomposition of yperite, namely the CâS bond cleavage and the S oxidation.
A new class of 3,4-disubstituted pyrroles has been prepared by the reaction of 1-aroyl-2-arylsul-fonylethenes and 1,2-diarylsulfonylethenes with tosyl methyl isocyanide.
Hydroxyl-Directed Stereoselective Diboration of Alkenes
作者:Thomas P. Blaisdell、Thomas C. Caya、Liang Zhang、Amparo Sanz-Marco、James P. Morken
DOI:10.1021/ja504228p
日期:2014.7.2
An alkoxide-catalyzed directed diboration of alkenyl alcohols is described. This reaction occurs in a stereoselective fashion and is demonstrated with cyclic and acyclichomoallylic and bishomoallylic alcohol substrates. After oxidation, the reaction generates 1,2-diols such that the process represents a method for the stereoselective directed dihydroxylation of alkenes.
[EN] METHOD FOR PREPARING ORGANIC PEROXIDES ON SITE<br/>[FR] METHODE DE PREPARATION DE PEROXYDES ORGANIQUES SUR PLACE
申请人:AKZO NOBEL NV
公开号:WO2005075419A1
公开(公告)日:2005-08-18
The present invention relates to a process for preparing an organic peroxide and the subsequent use thereof in a (co)polymerization reaction, wherein the process comprises the steps (a), b1 (or b2), (c), (d), and (e), said steps being: (a) the reaction of chlorine with carbon monoxide, (b1) the reaction of phosgene formed in step (a) with one or more alcohols in order to prepare chloroformate, (b2) the reaction of phosgene formed in step (a) with one or more organic acids to prepare acid chloride, optionally in the presence of a catalyst suitable to effect the reaction of phosgene with said one or more organic acids, (c) the reaction of chloroformate, acid chloride, or mixture thereof with (in)organic hydroperoxide and base in an aqueous environment, (d) the transfer of organic peroxide formed in step (c) to a polymerization vessel, and (e) the (co)polymerization of monomer in the polymerization vessel in the presence of one or more organic peroxides transferred in step (d), wherein all of steps (a)-(e) are conducted at one site.
Nickel-Phosphine Complex-Catalyzed Grignard Coupling. I. Cross-Coupling of Alkyl, Aryl, and Alkenyl Grignard Reagents with Aryl and Alkenyl Halides: General Scope and Limitations
(s)), aryl, and alkenyl Grignard reagents and nonfused, fused, and substituted aromatic halides and haloolefins. Limitations lie in sluggish reactions between alkyl Grignard reagents and dihaloethylenes. The most effective catalysts are [Ni(C6H5)2P(CH2)3P(C6H5)2}Cl2] for alkyl and simple aryl Grignard reagents, [Ni(CH3)2P(CH2)2P(CH3)2}Cl2] for alkenyl and allylic Grignard reagents and [NiP(C6H5)3}2-Cl2]
已经确定,二卤代二膦镍 (II) 配合物对格氏试剂与芳基和链烯基卤化物的选择性交叉偶联表现出极高的催化活性。由于该催化反应程序简单、反应条件温和、偶联产物的收率和纯度高,以及广泛适用于涉及伯和仲烷基的反应(无论β-的存在与否),该催化反应可用于合成实践。氢 (s))、芳基和烯基格氏试剂以及非稠合、稠合和取代的芳族卤化物和卤代烯烃。限制在于烷基格氏试剂和二卤乙烯之间的缓慢反应。对于烷基和简单的芳基格氏试剂,最有效的催化剂是 [Ni(C6H5)2P(CH2)3P(C6H5)2}Cl2],[Ni(CH3)2P(CH2)2P(CH3)2}Cl2] 用于烯基和烯丙基格氏试剂,[NiP(C6H5)3}2-Cl2] 用于空间位阻芳基格氏试剂和卤化物。膦配体对...的巨大稳定作用