Hydrolytic degradation of .BETA.-carboline-type monoterpenoid glucoindole alkaloids : A possible mechanism for harman formation in Ophiorrhiza and related rubiaceous plants.

Abstract

A new mechanism is proposed for harman formation which operates, probably secondarily, in Ophiorrhiza and other related Rubiaceous plants.It is based on the observed easy fragmentation. of some β-carboline-type monoterpenoid glucoindole alkaloids by enzymatic cleavage of the glucoside bonds. Isolation of two new glucosidic alkaloids, lyalosidic acid and 10-hydroxylyalosidic acid, is also described.