BIOTRANSFORMATION AND PHYLOGENY .4. MICROBIAL OXIDATION OF ARISTOLENEPOXIDE TO PHYTOTOXINS

Main metabolites of the microbial oxidation of (6R)-aristolenepoxide a re 5 alpha-, 9 beta-, 10 beta-, and 15-hydroxy-aristolenepoxide. Arist olene-7,14-oxide-6 alpha-ol was also formed. Some of them showed modes t phytotoxic activity in the cress test, where 9 beta-hydroxy-aristole nepoxide is the most active one. The actvity of the strains mirrored t heir phylogenetic positions. Bacteria were most active in oxidizing 15 -hydroxy-aristolenepoxide to the aldehyde, while fungi, especially Bas idiomycotina, were more active in the hydroxylation of the substrate t han bacteria. (C) 1996 Academic Press, Inc.