Biotransformation of two cytotoxic terpenes, alpha-santonin and sclareol by Botrytis cinerea

Two cytotoxic terpenes, alpha-santonin (1) and sclareol (3) were biotransformed by a plant pathogenic fungus Botrytis cinerea to produce oxidized metabolites in high yields. Alpha-Santonin (1) on fermentation with the fungus for ten days afforded a hydroxylated metabolite identified as 11beta-hydroxy-alpha-santonin (2) in a high yield (83%), while sclareol (3) was metabolized to epoxysclareol (4) (64%) and a new compound 8-deoxy-14,15-dihydro-15-chloro-14-hydroxy-8,9-dehydrosclareol (5) (7%), representing a rare example of microbial halogenation.