2006 Volume 54 Issue 3 Pages 320-324
Fermentation of 3-hydroxyflavone (1) with Beauveria bassiana (ATCC 13144) yielded 3,4′-dihdroxyflavone (3), flavone 3-O-β-D-4-O-methylglucopyranoside (4) and two minor metabolites. 7-Hydroxyflavone (2) was transformed by Nocardia species (NRRL 5646) to 7-methoxyflavone (5) whilst Aspergillus alliaceus (ATCC 10060) converted it to 4′,7-dihydroxyflavone (6). Flavone 7-O-β-D-4-O-metylglucopyranoside (7) and 4′-hydroxyflavone 7-O-β-D-4-O-methylglucopyranoside (8) were the metabolic products of 7-hydroxyflavone (2) when fermented with Beauveria bassiana (ATCC 7159). One of the minor metabolites of 3-hydroxyflavone (1) was tentatively assigned a β′-chalcanol structure (9). Compounds 4, 7 and 8 are reported as new compounds. Structure elucidation of the metabolites was based on spectroscopic data.