title: Preparative isolation of cyclolanostane-type saponins from Astragalus membranaceus bge. var. mongholicus (Bge.) Hsiao by TLC-MS/MS guided high-speed counter-current chromatography.
abstract: Two cyclolanostane-type saponins, astragalosides I and II, were first identified by TLC-MS/MS in the ethyl acetate extract of the roots of Astragalus membranaceus Bge var. mongholicus (Bge.) Hsiao without chemical reference substances. They were then isolated by high-speed counter-current chromatography with a two-step two-phase solvent system of ethyl acetate-2-propanol-water (5:1:5, 50:1:50, v/v/v). The quantities of astragalosides I and II isolated from 1 g of the crude extract were 30.2 mg and 16.5 mg, respectively. Their purities were found to be over 95% by HPLC-ELSD analysis. Their chemical structures were confirmed by 1H and 13C nuclear magnetic resonance analysis.
authors.affiliation: Chinese Medicine Laboratory, Hong Kong Jockey Club Institute of Chinese Medicine, Shatin N.T., Hong Kong, P. R. China.
authors.forename: Quan Bin
authors.initials: QB
authors.lastname: Han
authors.forename: Jing Zheng
authors.initials: JZ
authors.lastname: Song
authors.forename: Chun Feng
authors.initials: CF
authors.lastname: Qiao
authors.forename: Lina
authors.initials: L
authors.lastname: Wong
authors.forename: Hong Xi
authors.initials: HX
authors.lastname: Xu
mesh_terms: D027885:Astragalus propinquus / Q000737:chemistry*; D002855:Chromatography, Thin Layer; D003377:Countercurrent Distribution; D007810:Lanosterol / Q000031:analogs & derivatives* / Q000302:isolation & purification; D012503:Saponins / Q000302:isolation & purification*; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry
chemical_list: D012503:Saponins; C497083:lanostanoid; D007810:Lanosterol