Exhibits a coumarin 7-hydroxylase activity. Active in the metabolic activation of hexamethylphosphoramide, N,N- dimethylaniline, 2-methoxyacetophenone, N- nitrosomethylphenylamine, and the tobacco-specific carcinogen, 4- (methylnitrosamino)-1-(3-pyridyl)-1-butanone. Possesses phenacetin O-deethylation activity.