Hydroxylation of DHEA, androstenediol and epiandrosterone by Mortierella isabellina AM212. Evidence indicating that both constitutive and inducible hydroxylases catalyze 7 alpha- as well as 7 beta-hydroxylations of 5-ene substrates

The course of transformation of DHEA, androstenediol and epiandrosterone in Mortierella isabellina AM212 culture was investigated. The mentioned substrates underwent effective hydroxylation; 5-ene substrates - DHEA and androstenediol - were transformed into a mixture of 7 alpha- and 7 beta- allyl alcohols, while epiandrosterone was converted into 7 alpha- (mainly), 11 alpha- and 9 alpha- 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 C-7-H alpha and C-7-H beta bonds by the same enzyme is a reasonable assumption.