Biotransformation of testosterone and pregnenolone catalyzed by the fungus Botrytis cinerea.

Testosterone (1), a male sex hormone, and pregnenolone (2), a precursor of many steroidal hormones, were oxidized by fermentation with the fungus Botrytis cinerea. The fermentation of 1 yielded 7beta,17beta-dihydroxyandrostan-3-one (3) (73%) in a yield comparable to chemical transformations. Fermentation of 2 by the same fungus afforded a major metabolite 3beta,11alpha, 16beta-trihydroxypregn-5-en-20-one (4) (39%) along with a minor metabolite 11alpha,16beta-dihydroxypregn-4-ene-3,20-dione (5) (6%). The metabolites are characterized by detailed physical and spectroscopic studies.