Microbial transformation of antifertility agents, norethisterone and 17α-ethynylestradiol

Abstract

The microbial transformation of oral contraceptive norethisterone (1) by Cephalosporium aphidicola afforded an oxidized metabolite, 17α- ethynylestradiol (2), while the microbial transformation of 2 by Cunninghamella elegans yielded several metabolites, 19-nor-17α-pregna-1,3,5 (1O)-trien-20-yne-3,4,17β-triol (3), 19-nor-17β-pregna-1,3,5 (10)-trien-20-yne-3,7α,17β-triol (4), 19-nor-17α-pregna-1,3,5 (10)-trien-20-yne-3,11α,17β-triol(5), 19-nor-17α-pregna-1,3,5 (10)-trien-20-yne-3,6β,17β-triol (6) and 19-nor-17α-pregna-1,3,5 (10)-trien-20-yne-3,17β-diol-6β-methoxy (7). Metabolite 7 was found to be a new compound. These metabolites were structurally characterized on the basis of spectroscopic techniques.