Gynostemosides A-E, megastigmane glycosides from Gynostemma pentaphyllum

Megastigmane glycosides (1-5) were isolated from the whole plants of Gynostemma pentaphyllum. Their absolute structures were elucidated by means of spectroscopic methods including 2D NMR, HR-ESIMS, and circular dichroism (CD), as well as by chemical transformations.