Microbial transformations of steroids--III. Transformation of progesterone by Sepedonium ampullosporum.

The 16 alpha-steroid hydroxylating fungus Sepedonium ampullosporum (CMI strain 203 033) transformed progesterone into 16 alpha-hydroxyprogesterone and four other major metabolites which have not been reported previously for this organism, 6 beta-hydroxyprogesterone, 17 alpha-hydroxyprogesterone, 16 alpha-hydroxyandrostenedione and 16-oxotestosterone (16-ketotestosterone). Among the minor metabolites we have been able to identify 15 alpha-hydroxyprogesterone. This compound has not been reported for S. ampullosporum. The conditions used for transformation had comparatively little effect on the relative proportions of products formed, 16 alpha-hydroxyprogesterone always being the predominant metabolite, but had a major effect on the total yields of metabolites isolatable. These findings suggest that one or more constitutive enzyme systems were responsible for the transformations.