LAUSR

&NA; Biotransformation of an orally active contraceptive drug, drospirenone (1), by Cunninghamella elegans ATCC 36114 yielded four new metabolites, 6&bgr;,7&bgr;,15&bgr;,16&bgr;‐dimethylene‐3‐oxo‐14&agr;‐hydroxy‐17&agr;‐pregn‐4‐ene‐21,17‐carbolactone (2), 6&bgr;,7&bgr;,15&bgr;,16&bgr;‐dimethylene‐3,11‐dioxo‐17&agr;‐pregn‐4‐ene‐21,17‐carbolactone (3), 6&bgr;,7&bgr;,15&bgr;,16&bgr;‐dimethylene‐3,12‐dioxo‐17&agr;‐pregn‐4‐ene‐21,17‐carbolactone (4), and 6&bgr;,7&bgr;,15&bgr;,16&bgr;‐dimethylene‐3‐oxo‐11&bgr;,14&agr;‐dihydroxy‐17&agr;‐pregn‐4‐ene‐21,17‐carbolactone (5), along with a known metabolite, 6&bgr;,7&bgr;,15&bgr;,16&bgr;‐dimethylene‐3‐oxo‐11&agr;‐dihydroxy‐17&agr;‐pregn‐4‐ene‐21,17‐carbolactone (6). This study provides not only new analogues of orally active contraceptive drug, drospirenone, but also help in understanding the metabolism of this important drug. Graphical abstract Figure. No caption available. HighlightsBiotransformation of drospirenone by Cunninghamella elegans afforded six compounds.Five metabolites were undescribed products in the chemical bibliography.Microbial transformation of drospirenone involves oxidation at C‐11, ‐12 and ‐14.Biotransformation of drospirenone is a good tool for addition of C=O and OH groups.