1. The non-enzymic reactions of trans-4-nitrosostilbene, 4-nitrosobibenzyl, 2-nitrosofluorene and p-nitrosotoluene with glutathione were studied. 2. Three types of reaction products have been identified, namely, the corresponding hydroxylamine, amine, and a water-soluble adduct which hydrolyses under acidic or alkaline conditions to an amine and glutathione sulphinic acid. 3. Reduction to the amine is explained by formation of adducts which are reduced by glutathione with the production of oxidized glutathione. 4. The relevance of this reaction for metabolic activation and inactivation of aromatic amines in vivo is discussed.

Diethylstilbestrol and trans-4-dimethylaminostilbene are metabolically activated and several of their metabolites are able to react with cellular macromolecules. Some of the problems are discussed which are encountered in linking a particular metabolite with the mutagenic and carcinogenic properties of these compounds.