Triterpenoid saponins from the roots of Panax notoginseng with protective effects against APAP-induced liver injury

Five previously undescribed protopanaxatriol-type saponins, notoginsenosides Ta-Te (1-5), together with eighteen known triterpenoid saponins (6-23) were isolated from the roots of Panax notoginseng. The structures of new compounds were determined by HRESIMS and NMR spectroscopic analyses and chemical methods. Compounds 1 and 2 were the first examples of ginsenosides featuring a 6-deoxy-β-d-glucose moiety from Panax species. Compounds 1-4, 7, 10, 12, 21-22 showed protective effects on L02 cells against the injury of acetaminophen (APAP). Among them, notoginsenoside R1 (12), ginsenoside Rg1 (21), and ginsenoside Re (22) were the most potent ones, with cell viabilities >80%. Moreover, compounds 12 and 22 remarkably alleviated APAP-induced liver injury in mice. These saponins are potential hepatoprotective agents.