Baeyer–Villiger oxidation of some steroids by Aspergillus tamarii MRC 72400

Abstract

Biotransformations of epiandrosterone (1), dehydroepiandrosterone (2), testosterone (3), progesterone (4) and pregnenolone (5) byAspergillus tamariiMRC 72400 for 5 days have been reported and the results of these incubations have been compared with previously published data obtained withAspergillus tamariiQM 1223.A. tamariiMRC 72400 showed higher Bayer–Villiger monooxygenase activities thanA. tamariiQM 1223 did. Apart from pregnenolone (5),A. tamariiMRC 72400 metabolized these steroids in different ways. Incubation of epiandrosterone (1) afforded 3β,11β-dihydroxy-5α-androstan-17-one (6) (3%) and 3β-hydroxy-17a-oxa-D-homo-5α-androstan-17-one (7) (9.5%). Incubation of dehydroepiandrosterone (2) afforded 3β-hydroxy-17a-oxa-D-homoandrost-5-en-17-one (8) (28%), testolactone (9) (6%), 3β,7β-dihydroxyandrost-5-en-17-one (10) (13%) and 3β,7α-dihydroxy- androst-5-en-17-one (11) (24%). Incubation of testosterone (3) afforded testolactone (9) (58%). Incubation of progesterone (4) also afforded testolactone (9), however in higher yield (86%). Incubation of pregnenolone (5) afforded 3β-hydroxy-17a-oxa-D-homoandrost-5-en-17-one (8) (25%) and testolactone (9) (27%).