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.