Hydroxylation of DHEA, androstenediol and epiandrosterone by Mortierella isabellinaAM212. Evidence indicating that both constitutive and inducible hydroxylases catalyze 7α- as well as 7β-hydroxylations of 5-ene substrates

Abstract

The course of transformation of DHEA, androstenediol and epiandrosterone in Mortierella isabellinaAM212 culture was investigated. The mentioned substrates underwent effective hydroxylation; 5-ene substrates – DHEA and androstenediol – were transformed into a mixture of 7α- and 7β- allyl alcohols, while epiandrosterone was converted into 7α- (mainly), 11α- and 9α- monohydroxy derivatives. Ketoconazole and cycloheximide inhibition studies suggest the presence of constitutive and substrate-induced hydroxylases in M. isabellina. On the basis of time course analysis of the hydroxylation of DHEA and androstenediol, the oxidation of allyl C₇-H_α and C₇-H_β bonds by the same enzyme is a reasonable assumption.