Enzymic oxidative modification of prenyl groups. The biosynthetic origins of the E-ring systems of rotenone and amorphigenin

Abstract

The major biosynthetic route to amorphigenin in Amorpha fruticosa is from rot-2′-enonic acid via cyclisation to rotenone with the (E)-methyl of the former becoming the methylene of the latter, followed by positionally non-specific hydroxylation; a subsidiary route involves positionally non-specific hydroxylation of rot-2′-enonic acid followed by chemospecific (for the methyl group) cyclisation to amorphigenin.