Fungal transformation and T-cell proliferation inhibitory activity of melengestrol acetate and its metabolite

Biotransformation of melengestrol acetate (MGA, 17a-acetoxy-6-methyl-16-methylenepregna-4, 6-diene-3,20-dione) (1) was investigated for the first time by using fungal cultures. Incubation of compound 1 with Cunninghamella blakesleeana yielded a new major metabolite, 17a-acetoxy-11b- hydroxy-6-methyl-16-methylenepregna-4,6-diene-3,20-dione (2). The metabolite 2 was purified by using HPLC, followed by characterization through