Microbial Transformation of Sampangine

Microbial transformation studies of the antifungal alkaloid sampangine (2) have revealed that it is metabolized by a number of microorganisms. Using a standard two-stage fermentation technique, Beauvaria bassiana (ATCC 7159), Doratomyces microsporus (ATCC 16225), and Filobasidiella neoformans (ATCC 10226) produced the 4'-O-methyl-beta-glucopyranose conjugate (3), while Absidia glauca (ATCC 22752), Cunninghamella elegans (ATCC 9245), Cunninghamella species (NRRL 5695), and Rhizopus arrhizus (ATCC 11145) produced the beta-glucopyranose conjugate (4). Metabolites 3 and 4 have been characterized on the basis of spectral data. Both 3 and 4 had significant in vitro activity against Cryptococcus neoformans but were inactive against Candida albicans. Metabolite 4 was inactive in vivo in a mouse model of cryptococcosis.