Triterpenoid Saponins and Oligosaccharides from the roots of Polygala tenuifolia Willd.

AimTo study the chemical constituents and bioactivities of the roots of Polygala tenuifolia Willd.MethodsBioactivity-guide was applied to study the chemical constituents of P. tenuifolia, and the chemical structures were determined by application of spectroal data (NMR, MS).ResultsOne new, four known triterpenoid saponins and six oligosaccharides were obtained and their structures were identified as 3-O-β-D-glucopyranosyl-presenegenin 28-O-α-L-arabinopyranosyl-(1→ 3)-β-D-xylopyranosyl-(1→4)-[β-D-apiofuranosyl-(1→3)]-α-L-rhamnopyranosyl-(1→2)-[3-O-3, 4, 5-trimethoxycinnamoyl]-β-D-fucopyranosyl ester (onjisaponin Wg, 1), onjisaponins Fg (2), Ng (3), R (4), and O (5), tenuifolioses A (6), B (7), C(8), I (9), K (10), and G (11).ConclusionCompound 1 is a new saponin. Compounds 6 and 7 showed neuroprotective activity against glumate and serum deficiency at the concentration of 1×10−5 mol·L−1. Compounds 7 and 8 potentiated basal synaptic transmission in the dentate gyrus of anesthetized rats. The NMR data of 2–5 were reported for the first time.