Vinyl acetate

About: Vinyl acetate is a research topic. Over the lifetime, 15970 publications have been published within this topic receiving 162142 citations. The topic is also known as: Ethenyl acetate & Ethenyl ethanoate.

Mutagenic and alkylating metabolites of halo-ethylenes, chlorobutadienes and dichlorobutenes produced by rodent or human liver tissues. Evidence for oxirane formation by P450-linked microsomal mono-oxygenases.

Abstract: Mutagenicity, expressed as the number of his + revenants per μmole of test compound per hour of exposure, was estimated in two strains of S. typhimurium in the presence of a postmitochondrial mouse-liver supernatant, following exposure to vapours of one of a series of halo-olefins. Their activity was in the following descending order: 3,4-dichlorobutene-1 > 1-chlorobutadiene (technical grade) > 2-chlorobutadiene > vinyl bromide > vinylidene chloride > vinyl chloride; marginal mutagenicity was detected in the presence of 1,1,2-trichloroethylene and 1,1-difluoroethylene, and none with tetrachloroethylene and vinyl acetate. Liver fractions from humans converted vinyl chloride, vinyl bromide, vinylidene chloride and 2-chlorobutadiene into mutagens. In the plate incorporation assay, 1,4-dichlorobutene-2 was mutagenic per se, and addition of microsomal fractions from human or mouse liver enhanced the mutagenicity; a synthetic putative metabolite, 1,4-dichloro-2,3-epoxybutane was less mutagenic than the parent olefin in strain TA100. Treatment of rats with phenobarbital or 3-methylcholanthrene caused an up to 2-fold increase in the liver microsome-mediated mutagenicities of vinyl chloride and vinylidene chloride in S. typhimurium TA1530; while treatment with pregnenolone-16α-carbonitrile, aminoacetonitrile or disulfiram decreased the mutagenic effects. Vinyl chloride, and probably vinyl bromide, were shown to be epoxidized by mouse-liver microsomes; volatile alkylating metabolites were trapped by reaction with excess 4-(4-nitrobenzyl)pyridine and analysed spectrally. 2-Chlorobutadiene also yielded an alkylating intermediate, but 1,1-difluoroethylene, 1,1-dichloroethyleneand 1,1,2-trichloroethylene did not. 2-Chloro- and 1-chlorobutadiene, 3,4-dichlorobutene-1, 1,4-dichlorobutene-2 and its 2,3-epoxy derivative showed alkylating activity with 4-(4-nitrobenzyl)pyridine, which was not related quantitatively to mutagenic activity in S. typhimurium TA100 in the absence of a metabolic activation system. These data support the hypothesis that an oxidation of the double bond in certain halo-olefins, which is dependent on microsomal mono-oxygenases is a common pathway in the formation of biologically reactive intermediates. The relevance of the metabolites formed during such oxidative processes to the mutagenic, toxic and carcinogenic activities in vivo of some of the parent compounds is discussed.

Drug-delivery device comprising certain polymeric materials for controlled release of drug

Abstract: Drug-delivery device for releasing a drug at a continuous and controlled rate for a prolonged period of time is comprised of a shaped body of polymeric material containing a pharmaceutically acceptable drug and permeable to passage of the drug by diffusion. The polymeric material is an ethylene-vinyl acetate copolymer having a vinyl acetate content of about 4 to 80% by weight and a melt index of about 0.1 to 1000 grams per 10 minutes.

Copolymerization of vinyl acetate with ethylene by palladium/alkylphosphine-sulfonate catalysts.

Abstract: Coordination copolymerization of vinyl acetate (VAc) with ethylene, leading to linear copolymers that possess in-chain -CH(2)CH(OAc)- units, has been accomplished using novel palladium complexes bearing alkylphosphine-sulfonate ligands.