Dammarane-type glycosides from Gynostemma pentapyllum

Gynostemma pentapyllum (Thunb.) Makino, a perennial creeping herb belonging to the Cucurbitaceae, is widely distributed in Korea, China, and Japan. The genus Gynostemma is a rich source of dammarane-type glycosides which are structurally related to the ginseng saponin. Many of these saponins were reported to exert a wide spectrum of pharmacological effects, including hypolipidermic, anti-inflammatory, immunomodulatory, and anticarcinogenic activities. In our continuing search for bioactive components from medicinal plant, two new dammarane-type glycosides together with twelve known compounds were isolated from the aerial parts of G. pentapyllum using column chromatographic separation techniques. The structures of these compounds were determined by 1D- (¹H, ¹³C and DEPT), 2D- (HSQC, HMBC, COSY, NOESY) NMR and HRESI-MS spectrum. We report herein the isolation and structure determination of these two new dammarane-type glycosides.