Biotransformation of oleanolic and maslinic methyl esters by Rhizomucor miehei CECT 2749

The biotransformation of methyl oleanolate (3), methyl maslinate (4), a 9(11),12-diene derivative (6) of methyl oleanolate, and a 12β,13β-epoxy derivative (13) of methyl maslinate, by Rhizomucor miehei CECT 2749, are described. Metabolites with hydroxylations at C-30, C-7β, or C-15α have been isolated. This fungus has also produced 9(11)-ene, 11-oxo, 12-oxo-13R, or 12-oxo-28,13β-olide derivatives.