Novel Cyclopentenoid Cyanohydrin Rhamnoglucosides from Flacourtiaceae¹

Abstract

Two novel cyclopentenoid cyanohydrin glycosides, (1S,4R)-and (1R,4S)-1-[6-O-(α-L-rhamnopyranosyl)-β-D-glucopyranosyloxy]-4-hydroxy-2-cyclopentene-1-carbonitrile, were isolated from seeds of the Indian medicinal plant Hydnocarpus pentandra (F. Ham.) Oken (Flacourtiaceae) and characterized by optical rotations as well as ¹H-and ¹³C-NMR spectra. The structural assignment is founded on these data and on degradation with α-L-rhamnosidase to the corresponding β-D-glucopyranosides, epivolkenin and taraktophyllin, also present in the seeds in small amounts. Earlier reports of cyclopentenoid rhamnoglucosides from Passifloraceae are rejected.