REDUCTION OF N-NITROSODIPHENYLAMINE TO THE CORRESPONDING HYDRAZINE BY GUINEA PIG LIVER PREPARATIONS

Abstract

The present study provides first evidence for enzymatic reduction of a noncyclic nitrosamine to the corresponding hydrazine. Under anaerobic conditions, N-nitrosodiphenylamine was reduced to 1, 1-diphenylhydrazine by guinea pig liver 9, 000xg supernatant or cytosol in the presence of an NADPH-generating system and FAD, or NADH and FAD. However, guinea pig liver microsomes did not catalyze the reduction of the nitrosamine at all. The reduction product was isolated from the reaction mixture and identified unequivocally by comparing with authentic samples its mass and UV spectra, and its behavior in HPLC and TLC. Under aerobic conditions, no formation of the hydrazine was observed by HPLC and TLC examinations. However, when aerobic incubation was performed in the presence of acetaldehyde, a reduction product was isolated and identified as the acetaldehyde hydrazone derivative.