Metabolism of 2-nitro-1-phenylpropane to phenylacetone by rabbit liver microsomes

Phenylacetone was found to be the major metabolite formed when 2-nitro-1-phenylpropane was incubated with rabbit liver microsomes. The enzymatic character of the reaction was demonstrated by the increase of product with microsomal protein and dependency on NADPH and oxygen. Furthermore, phenobarbital induction markedly increased the formation of phenylacetone. Carbon monoxide decreased the reaction indicating the involvement of a metalloenzyme. Experiments with H218O indicated that the carbonyl oxygen originated from water. It is suggested that the microsomal metabolism of 2-nitro-1-phenylpropane involves an enzymatic step followed by chemical hydrolysis of an intermediate, possibly a secondary nitronic acid.