Chemical Constituents of the Roots of Astragalus polycladus var. nigrescens

A new cycloartane triterpenoid, 24-acetylcyclocantogenin (1), along with five cycloartane triterpenoids (2-6), eight steroids (7-14) and nine other known compounds (15-23), was obtained from the methanol extract of roots of Astragalus polycladus var. nigrescens. Their structures were elucidated based on extensive spectroscopic analysis (1D and 2D-NMR, MS and IR). They were isolated from A. polycladus var. nigrescens for the first time.