Biotransformation of corticosteroids by Penicillium decumbens ATCC 10436.

The biotransformation of a series of corticosteroids by the fungus Penicillium decumbens ATCC 10436 has been investigated. Conversion to the corresponding 5 alpha-dihydrosteroid was observed for all the delta 4-3-ketosteroids studied with the exception of deoxycorticosterone, which was converted to a delta 1.4-diene. Deoxycorticosterone acetate was, however, converted to a 5 alpha-dihydro product concomitant with ester hydrolysis. Other substrates carrying a C-21 acetoxy group were also hydrolyzed to the alcohol. In two cases (resulting from deoxycorticosterone acetate and 11-deoxycortisone) the 5 alpha-3-keto product was further reduced to the 3 beta-alcohol. No reduction of delta 1.4-dienes was observed.