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

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