Cunninghamella blakesleeana-mediated biotransformation of an oral contraceptive drug, levonorgestrel (1), yielded a new metabolite, 13β-ethyl-17α-ethynyl-10,17β-dihydroxy-4,6-dien-3-one (2), and two known metabolites 3 (13β-ethyl-17α-ethynyl-10β,17β-dihydroxy-4-en-3-one), and 4 (13β-ethyl-17α-ethynyl-6β,17β-dihydroxy-4-en-3-one) at an ambient temperature using aqueous media. Hydroxylation and dehydrogenation of compound 1 was observed during the bio-catalytic transformation. The structure of a new metabolite 2 was determined by 1H, 13C, and 2DNMR and HR-EIMS spectroscopic techniques.
Keywords: Contraceptive drug; Cunninghamella blakesleeana; biotransformation; levonorgestrel.