Antisweet Natural Products. V. Structures of Gymnemic Acids VIII-XII from Gymnema sylvestre R. BR.

Abstract

Five oleanane-type triterpenoid saponins, gymnemic acids VIII-XII as antisweet principles were isolated from the leaves of Gymnema sylvestre (Asclepiadaceae). Their structures were established on the basis of spectral and chemical evidence. They were characterized as glucosideuronic acid derivatives of gymnemagenin acylated with acetyl, tigloyl and/or 2-methylbutyroyl moieties.