Microbial transformations of steroids—VI. transformation of testosterone and androstenedione by Botryosphaerica obtusa

Abstract

The 7β progesterone-hydroxylating microorganism Botryosphaerica obtusa [1] was tested for its ability to hydroxylate at this site the C-19 androstene-based compounds, androstenedione (androst-4-ene-3,17-dione) and testosterone (17β-hydroxyandrost-4-en-3-one). Only very limited 7β hydroxylation of both substrates was observed. The products included traces of 7β-monohydroxytestosterone and 6β,7β-dihydroxyandrostenedione from testosterone, and of 6β,7β-dihydroxyandrostenedione from androstenedione. 6β,7β-Dihydroxyandrostenedione does not appear to have been reported previously as a microbial transformation product. Both substrates were monohydroxylated in significant amounts at the isomeric 7α site and at the 6β site. Testosterone was also significantly monohydroxylated at the 15α site and in minor amounts at the 11α and 12β sites. Some monohydroxytestosterones had also been oxidised at their 17-OH group, converting them into the corresponding monohydroxy androstenediones. The 7α-hydroxy metabolites and 15α-hydroxytestosterone being chemically demanding to synthesis are valuable microbial transformation products.