Watabe, T; Hiratsuka, A; ,
The present review deals with metabolism of the vinyl side chain and the benzene nucleus of the plastic monomer, styrene, in vitro and in vivo in relation to mutagenicity and carcinogenicity exerted by its reactive metabolic intermediates, phenyloxiran, 1-vinylbenzene 1,2-oxide and 3,4-oxide. Phenyloxiran plays an important role as an intermediate in the vinyl side chain oxidation to phenylethanediol, mandelic acid, phenylglyoxylic acid, benzoic acid, hippuric acid, mercapturic acids and phenylacetic acid. The mercapturic acids are directly correlated with the regioisomeric glutathione conjugates of phenyloxiran. Stereochemistry in the formation, hydrolysis, and GSH-conjugation of phenyloxiran has very recently established in relation to enantioselectivity and regioselectivity of the enzymaticre actions. 1-Vinylbenzene 1,2- and 3,4-oxides, new candidates for reactive intermediates of styrene, are specific precursors of 2- and 4-vinylphenols, respectively, in vivo and in vitro and have potent mutagenicity at very low concentrations toward Salmonella typhimurium TA 100 but not toward the TA 98 strain bacteria. Data strongly suggest the vinylbenzene oxides play more important roles in the mutagenicity of styrene in the presence of a metabolic activation system. © 1983, The Pharmaceutical Society of Japan. All rights reserved.