The C-1(2)-dehydtrogenation of 6-methylene Androstenedione to Exemestane, an Aromatase Inhibitor Used for the Treatment of Breast Cancer

Exemestane is an aromatase inhibitor widely used for the treatment of postmenopausal breast cancer patients. Several precursors are used for its synthesis; however the final step is C-1(2) dehydrogenation of the resultant steroid to yield exemestane. A sequence of hazardous chemical reactions is required for the final step of dehydrogenation. The present work was carried out to replace the chemical reaction with microbial catalysis. Microorganisms reported in the literature to catalyze C-1(2) dehydrogenation of various steroids were screened for dehydrogenation of 6-methylene androstenedione, a commonly used precursor for the synthesis of exemestane. The bacterial strains Delftia acidovorans MTCC 3364, Arthrobacter simplex IAM 1660 and Arthrobacter simplex NCIM 2449 have shown promising results and may be used for enzymatic catalysis and to develop eco-friendly route for the synthesis of this exemestane.