A new progestin from fungal transformation of norethisterone and its comparative antimicrobial studies

Fungal transformation of a norethisterone (17α-ethynylestra-4-en-17β-ol-3-one) (1) by using Macrophomina phaseolina and Paecilomyces variotii was studied. A new metabolite, 17α-hydroxymethyl-androst-4-en-11β-ol-3-one-17β-acetate (2) with novel changes and a known metabolite, 17α-ethynylestradiol (3) were obtained from 1 by using M. phaseolina and P. variotii, respectively. Based on various spectroscopic techniques, the structures of both metabolites were characterized. The antimicrobial activities of 1-3 were also evaluated. Compound 1 was found to be moderately active against Salmonella paratyphi while 1-3 were almost inactive against other microorganisms.