[The structure of astrachrysosid A and the study of 2D-NMR on astrasieversianin XV and 7,2'-dihydroxy-3',4'-dimethoxy-isoflavane-7-O-beta-D-glycoside].

Six compounds were isolated from the root of Astragalus chrysopterus Bunge. One of them was identified as a new triterpenoid glycoside, named astrachrysoside A. Its structure was elucidated as 3-O-[alpha-L-rhamnopyranosyl (1----2) beta-D-xylopyranosyl]-cycloastragenol on the basis of physicochemical evidence and chemical reactions. The others were shown to be known compounds, astrasieversianin XV (II), 7,2'-dihydroxy-3',4'-dimethoxy-isoflavane-7-O-beta-D-glucoside (III), soyasaponin I, daucosterol and beta-sitosterol. Full assignment of the chemical shift signals of II and III were established by various 2D-NMR techniques.