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 evaluation showed that compounds 6 − 11 exhibited certain scavenging effects on ABTS radical, where compounds 6 , 7 and 11 had IC₅₀ values of 0.208, 0.057 and 0.014 mg·mL⁻¹, respectively.