Steroid hydroxylations with Botryodiplodia malorum and Colletotrichum lini.

An improved procedure for the microbial hydroxylations of dehydroepiandrosterone (DHEA, 1) and 15 beta,16 beta-methylene-dehydroepiandrosterone (2) was studied using whole cells of Botryodiplodia malorum and Colletotrichum lini. C. lini catalyzed 7 alpha- and 15 alpha-hydroxylation of 1 and 7 alpha-hydroxylation of 2, while B. malorum gave 7 beta-hydroxylation of both the substrates. The stability of the enzymatic activity was higher in the presence of co-substrates (i.e., glucose or mannitol) allowing for repeated batches of the biotransformations. The yields of 7 alpha,15 alpha-dihydroxy-1 production were improved obtaining 5.8 gl(-1) (recovered product) from 7.0 gl(-1) of substrate. The structures of the hydroxylated products were assigned by a combination of two-dimensional NMR proton-proton and proton-carbon correlation techniques.