Traphanoside GO1, a new triterpenoid saponin from the aerial parts of Glinus oppositifolius with the inhibitory effect on PGE2 production in LPS-induced HepG2 cells

A new saponin, 3-O-[α-ʟ-rhamnosyl-(1→3)-β-D-glucopyranosyl]-28-O-β-D-glucopyranosyl serjanic acid (Traphanoside GO1, 11) along with eleven compounds (1-10 and 12) were isolated from the aerial parts of Glinus oppositifolius. The structures of all isolates were elucidated by analyzing extensive 1 D- and 2 D-NMR and HR-ESI-MS, comparing with reported literature data. Compounds 7-8, 10-11, and 90% ethanol extract (GOE90) were evaluated for the inhibitory effect on PGE2 production from activated HepG2 cells. Among these, new compound 11 showed the most potent inhibitory activity by suppressing LPS-induced PGE2 production on the HepG2 cells.