Objective To investigate trinorcycloartane triterpenoids from the stems and leaves of Astragalus membranaceus (AMSL). Methods Comprehensive separation and purification were performed using silica gel, ODS column chromatography, and high-performance liquid chromatography (HPLC). The structures of the compounds were identified by modern spectroscopic techniques. The cytotoxic activities of the compounds against PC12 cells were assessed using the MTT assay. Results Two trinorcycloartane triterpenoids were isolated from the n-butanol fraction of the 70% ethanol extract of AMSL, namely 1α,3β,12β,16β-tetrahydroxy-25,26,27-trinorcycloartan-24-oic acid methyl ester (1) and 1α,3β,12β-trihydroxy-25,26,27- trinorcycloartan-24,16β-olide (2). The MTT assay showed that compounds 1 and 2 exhibited varying degrees of cytotoxicity against PC12 cells within the concentration range of 5—100 μmol/L. Conclusions Compounds1 and 2 are identified as new trinorcycloartane triterpenoids, named cyclastraine K (1) and cyclastraine L (2), respectively. Both compounds 1 and 2 demonstrate cytotoxicity against PC12 cells.

Astragalus membranaceus (Fisch.) Bge.var.mongholicus(Bge.) Hsiao  /  triterpenoids  /  trinorcycloartane  /  PC12 cells  /  cyclastraine K  /  cyclastraine L