Five new spirosterol saponins from Allii Macrostemonis Bulbus

Five new spirostanol saponins(1-5)and seven known compounds(6-12)were isolated from the n-butanol fraction of 75％ethanol extract of Allii Macrostemonis Bulbus.The identification and structural elucidation of all the isolates were performed through extensive 1D and 2D NMR experiments,HR-ESI-MS data analysis and comparisons with literature values.Antioxidant evalu-ation showed that compounds 6-11 exhibited certain scavenging effects on ABTS radical,where compounds 6,7 and 11 had IC50 val-ues of 0.208,0.057 and 0.014 mg·mL-1,respectively.