Biotransformation of 4β-hydroxyeudesmane-1,6-dione by Gliocladium roseum and Exserohilun halodes

Biotransformation of sesquiterpene 4 beta -hydroxyeudesmane-1,6-dione by the filamentous fungi Gliocladium roseum and Exserohilum halodes was achieved. With Exserohilum halodes, only one metabolite was obtained, as a result of the regio- and stereoselective reduction of the keto group at C-1, which is difficult to achieve by chemical means. Five metabolites were produced with Gliocladium roseum, three of which, the 7 alpha -hydroxylated, the 7 alpha, 11- and the 1 alpha ,8 alpha -dihydroxylated derivatives, have not previously been reported, The hydroxylation at C-1 I is the main action of this microorganism, These 11-hydroxylated compounds can be chemically transformed into 6 beta ,12-eudesmanolides. (C) 2001 Published by Elsevier Science Ltd.