Isolation and Characterization of Dammarane-Type Saponins from Gynostemma pentaphyllum and Their Inhibitory Effects on IL-6-Induced STAT3 Activation

Five new dammarane-type saponins, gypenosides GD1-GD5 (1-5), along with six known saponins (6-11), were isolated from the aerial parts of Gynostemma pentaphyllum using various chromatographic methods. Their structures were elucidated by a combination of spectroscopic and spectrometric data, including 1D and 2D NMR and HRESIMS. All isolates were tested for their inhibitory effects on IL-6-induced STAT3 promoter activity in Hep3B cells. Compounds 1, 9, and 11 displayed potent inhibitory effects, with IC50 values ranging from 0.27 to 0.59 μM.