Microbial transformation of curdione by Mucor spinosus

Twenty strains of filamentous fungi (from nine genera) and four species of bacteria were screened for their capabilities to transform curdione (1). Site-specific hydroxylation and epoxidation of the substrate by Mucor spinosus AS 3.3450 were reported. Five compounds were obtained, and their structures were identified as 1β,10α-epoxycurdione (2), 1α,10β-epoxycurdione (3), 2β-hydroxycurdione (4), 11-hydroxycurdione (5) and 2β,11-dihydroxycurdione (6), respectively, on the basis of their spectral data. Among them, products 5 and 6 are new compounds. The biotransformation kinetics was also investigated.