Spin trapping of a free radical intermediate formed during microsomal metabolism of hydrazine

A radical formed during oxidative metabolism of hydrazine in rat liver microsomes was spin-trapped with alpha-phenyl-t-butylnitrone. The trapped species was identified as hydrazine radical by comparison of its ESR parameters and mass spectrum with those of the adduct formed during CuCl2 catalyzed oxidation of hydrazine. The requirement for oxygen and NADPH in the microsomal oxidation and the occurrence of a typical binding spectrum by difference spectroscopy suggest the involvement of the participation of the cytochrome P-450 enzyme system in the formation of hydrazine radical which must be a precursor of diimide during microsomal oxidation of hydrazine.