Biochemical studies of toxic agents. 15. The biosynthesis of ethylmercapturic acid sulphoxide

Abstract

(+)-Ethylmercapturic acid sulfoxide, (+)-N-acetyl-S-ethyl-L-cysteine S-oxide, was prepared as the dicyclohexylammonium salt, and ([long dash])-ethylmercapturic acid sulfoxide was prepared as both the free acid and the dicylohexylammon-ium salt. Some properties of these compounds have been reported. S-Ethyl-L-cysteine S-oxide, S-ethyl-L-cysteine SS-dioxide and N-acetyl-S-ethyl-L-cysteine SS-dioxide were also prepared. (+)-Ethylmercapturic acid sulfoxide was isolated as the dicyclohexylammonium salt from the urine of rats injected subcutaneously with S-ethyl-L-cysteine. The excretion of ethylmercapturic acid sulfoxide in the urine of rats that were injected subcutaneously with bromoethane or ethylmercapturic acid was demonstrated by radiochromatographic methods, and its excretion after the injection of S-ethyl-L-cysteine S-oxide was shown by paper chromatography.