Biogenetic relationship of the furanoacetylene phytoalexins in viciafaba

ABSTRACT

The biogenetic relationship between wyerone, wyerol and the 11, 12-dihydro analogues has been investigated. Labeled wyerone and dihydrowyerone were obtained by feeding sodium [2-14C] acetate to CuCl2-induced V. faba cotyledons, and separation by HPLC. Some of the wyerone was used for semisynthesis of wyerol. The three title compounds were then fed to induced bean cotyledons to establish any possible interconversion. Incorporation data indicated a 0.45% conversion of wyerone into dihydrowyerone and 3% reversed conversion. The highest incorporation was 13.3% conversion of wyerol into wyerone, accompanied by a small conversion [0.15%] of wyerol into dihydrowyerone. The results indicated that wyerone has been derived from wyerol, most probably, by oxidation