Oxidation of lynestrenol by the fungus Cunninghamella elegans.

Transformation of lynestrenol (19-nor-17alpha-pregn-4-en-20-yn-17beta-ol) (1) was carried out by incubation with Cunninghamella elegans to obtain 19-nor-17alpha-pregn-4-en-20-yn-3-one-10beta,17beta-diol (2), 19-nor-17alpha-pregn-4-en-20-yn-3-one-6beta,17beta-diol (3), and 19-nor-17alpha-pregn-4-en-20-yn-3beta,6beta,17beta-triol (4). Metabolite 4 was identified as a new compound. These metabolites were structurally characterised on the basis of spectroscopic techniques.