Novel dammarane saponins from Gynostemma pentaphyllum and their cytotoxic activities against HepG2 cells.
Bioorg Med Chem Lett. 2014 Oct 15 ;24(20):4831-3. Epub 2014 Sep 4. PMID: 25227718
Two new dammarane saponins, 2α,3β,12β-trihydroxydammar-20(22),24-diene-3-O-[β-D-glucopyranoxyl(1→2)-β-D-6″-O-acetylglucopyranoside (1, namely damulin C) and 2α,3β,12β-trihydroxydammar-20(21),24-diene-3-O-[β-D-glucopyranoxyl(1→2)-β-D-6″-O-acetylglucopyranoside (2, namely damulin D), were isolated from the ethanol extract of Gynostemma pentaphyllum, which had been heat processed by steaming at 125 °C. The NMR spectroscopic data of the novel saponins were completely assigned by using a combination of 2D NMR experiments including (1)H-(1)H COSY, HSQC, and HMBC. Their cytotoxic activities of human liver adenocarcinoma HepG2 cells were evaluated in vitro. They showed cytotoxicities against HepG2 cell line with IC50 of 40±0.7 and 38±0.5 μg/ml, respectively.