ASTRASIEVERSIANINS IX, XI AND XV, CYCLOARTANE DERIVED SAPONINS FROM ASTRAGALUS SIEVERSIANUS

Article abstract of DOI:10.1016/S0031-9422(00)81305-9

Sixteen triterpenoid saponins, astrasieversianins I-XVI, have been isolated from the methanol extract of the roots of Astragalus sieversianus.By heterogeneous acidic hydrolysis, all glycosides produced only one common aglycone which was identified as the known natural product astramembrangenin or cycloastragenol.On the basis of spectral analysis and chemical reactions, the structures of two new triterpenoid glycosides, astrasieversianin IX and XI, were assigned as the 3-O-<α-L-rhamnopyranosyl(1->2)>-(3'-O-acetyl)-β-D-xylopyranosyl-6-O-β-D-xylopyranoside and the 3-O-<α-L-rhamnopyranosyl(1->2)> -(4'-O-acetyl)-β-D-xylopyranosyl-6-β-D-xylopyranoside of cycloastragenol.Astrasieversianin XV was identified as the 20,24-epimer (20R,24S) of cyclosieversiside G (20S,24R). Key Word Index - Astragalus sieversianus; Leguminosae; cycloartane triterpene; astrasieversianin; astrasieversiagenin; triterpenoid saponins.