Biosynthesis of oleoside-, 10-hydroxyoleoside- and ligustaloside-type glucosides from secologanin

Abstract

A biosynthetic pathway from secologanin to oleoside-, 10- hydroxyoleoside- and ligustaloside-type secoiridoid glucosides was examined by feeding experiments in which the respective C-8 stereoisomers of [8-3H]- 8,10-epoxyse cologanin and [8-3H]-8,10-epoxysecoxyloganin as well as [carbomethoxy-2H3]secologanin were administered separately to three oleaceous plants. The results showed that (8S)-8,10-epoxysecologanin was an intermediate between the secologanin and secoiridoid glucosides of the three types.