Metabolic epoxidation of trans-4-acetylaminostilbene: A protective mechanism against its activation to a mutagen

Abstract Trans -4-acetylaminostilbene is activated by liver preparations to mutagens for Salmonella typhimurium . Since this compound is metabolized to the trans -α,β-epoxide and since many epoxides are ultimate mutagens, this epoxide was tested for direct mutagenicity. It was, however, found to be non-mutagenic, and, in contrast to the parent compound, the epoxide was no longer activated by liver preparations to mutagens. The same was found for the β-ketone and for the threo -α,β-dihydrodiol, which are formed metabolically from trans -4-acetylaminostilbene and from its α,β-epoxide. 4-Acetylaminobibenzyl showed a very weak mutagenic activity in the presence of the liver preparation. Thus, i…