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

A biosynthetic pathway from secologanin to oleoside-, 10-hydroxyoleoside- a nd ligustaloside-type secoiridoid glucosides was examined by feeding experi ments in which the respective C-8 stereoisomers of [8-H-3]-8,10-epoxysecolo ganin and [8-H-3]-8,10-epoxysecoxyloganin as well as [carbomethoxy-H-2(3)]s ecologanin were administered separately to three oleaceous plants. The resu lts showed that (8S)-8,10-epoxysecologanin was an intermediate between the secologanin and secoiridoid glucosides of the three types.