Microbial transformation of androst-4-ene-3,17-dione by Beauveria bassiana

The microbial transformation of androst-4-ene-3,17-dione (I) by the fungus Beauveria bassiana CCTCC AF206001 has been investigated using pH 6.0 and 7.0 media. Two hydroxylated metabolites were obtained with the pH 6.0 medium. The major product was 11α-hydroxyandrost-4-ene-3,17-dione (II) whereas the minor product was 6β,11α-dihydroxyandrost-4-ene-3,17-dione (III). On the other hand, four hydroxylated and/or reduced metabolites were obtained with the pH 7.0 medium. The major product was 11α,17β-dihydroxyandrost-ene-3-one (V) and the minor products were 17β-hydroxyandrost-ene-3-one (IV), 6β,11α,17β-trihydroxyandrost-ene-3-one (VI) and 3α,11α,17β-trihydroxy-5α-androstane (VII). The products were purified by chromatographic methods, and were identified on the basis of spectroscopic methods. This fungus strain is clearly an efficient biocatalyst for 11α-hydroxylation and reduction of the 17-carbonyl group.