Oleanane-Type Saponins from the Roots of Ligulariopsis shichuana and Their α-Glucosidase Inhibitory Activities.

Five new oleanane-type saponins, named ligushicosides A-E, and three known oleanane-type saponins were isolated from the roots of Ligulariopsis shichuana . Their structures were established by a combination of spectroscopic techniques, including 1D and 2D NMR and high resolution electrospray ionization mass spectroscopy (HR-ESI-MS). Furthermore, all isolates were evaluated for their yeast α -glucosidase inhibitory effects and exhibited potent inhibition against α -glucosidase, while compounds 1 and 2 showed excellent inhibitory activities. The 3- O -glycoside moiety in oleanane-type saponin is important for the α -glucosidase inhibitory effects.