Dammarane-Type Glycosides from Gynostemma pentaphyllum and Their Effects on IL-4-Induced Eotaxin Expression in Human Bronchial Epithelial Cells

Two new dammarane-type glycosides, 2α,3β,12β,20S-tetrahydroxydammar-24-ene-3-O-[β-d-glucopyranosyl(1→4)-β-d-glucopyranosyl]-20-O-[β-d-xylopyranosyl-(1→6)-β-d-glucopyranoside] (1) and 2α,3β,12β,20S-tetrahydroxydammar-24-ene-3-O-β-d-glucopyranosyl-20-O-[β-d-6-O-acetylglucopyranosyl-(1→2)-β-d-glucopyranoside] (2), were isolated from a MeOH extract of the leaves of Gynostemma pentaphyllum. Their structures were elucidated by 1D and 2D NMR spectroscopic interpretation as well as by chemical studies. The isolated compounds showed potential inhibitory effects on eotaxin expression in BEAS-2B bronchial epithelial cells.