[Study on steroidal saponins from Dioscorea zingiberensis and their platelet aggregation activities]

Using the absorbent resin, silica gel and ODS column chromatography as well as semi-preparative HPLC, ten compounds were isolated from 70% ethanol extract of tubers of Dioscorea zingiberensis C. H. Wright, and their structures were elucidated as trigoneoside XIIIa (1), parvifloside (2), trigoneoside IVa (3), deltoside (4), protobioside (5), lilioglycoside k (6), zingiberensis newsaponin I (7), deltonin (8), prosapogenin A of dioscin (9), and trillin (10) on the basis of NMR and MS spectral data analysis. Among these compounds, 1, 3, 5 and 6 were isolated from this plant for the first time. In the screening test on platelet aggregation, compounds 7 and 8 exhibited induction effect on platelet aggregation, while compound 9 exhibited significant inhibitory effect on platelet aggregation in vitro.