Microbial transformation of oxandrolone with Macrophomina phaseolina and Cunninghamella blakesleeana

Microbial transformation of oxandrolone (1) was carried out by using Cunninghamella blakesleeana and Macrophomina phaseolina. Biotransformation of 1 with M. phaseolina yielded four new metabolites, 11β,17β-dihydroxy-17α-(hydroxymethyl)-2-oxa-5α-androstan-3-one (2), 5α,11β,17β-trihydroxy-17α-methyl-2-oxa-androstan-3-one (3), 17β-hydroxy-17α-methyl-2-oxa-5α-androstan-3,11-dione (4), and 11β,17β-dihydroxy-17α-methyl-2-oxa-5α-androstan-3-one (5). Whereas a new metabolite, 12β,17β-dihydroxy-17α-methyl-2-oxa-5α-androstan-3-one (6), was obtained through the microbial transformation of oxandrolone (1) with C. blakesleeana. The structures of isolated metabolites were characterized on the basis of MS and NMR spectroscopic data.