Preparative isolation of cyclolanostane-type saponins from Astragalus membranaceus Bge. var. mongholicus (Bge.) Hsiao by TLC-MS/MS guided high-speed counter-current chromatography
✍ Scribed by Quan Bin Han; Jing Zheng Song; Chun Feng Qiao; Lina Wong; Hong Xi Xu
- Book ID
- 102924562
- Publisher
- John Wiley and Sons
- Year
- 2007
- Tongue
- English
- Weight
- 657 KB
- Volume
- 30
- Category
- Article
- ISSN
- 1615-9306
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✦ Synopsis
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.