ISOLATION AND IDENTIFICATION OF WUBANGZISIDE A AND B FROM POLYGALA CAUDATA REHD ET WILS

Two new xanthone glycosides, wubangziside A(Ⅲ) C₂₄H₂₆O₁₃, mp 130～131.5℃ and wubangziside B (Ⅳ) C₁₉H₁₈O₉, mp 215～217℃ and three known compounds, euxanthone (Ⅰ), stigmasteryl-D-glucoside (Ⅱ) and mangiferin (Ⅴ) were isolated from the bark and root bark of polygala caudata Rehd et Wils.The structures of wubangziside A and B were elucidated to be euxanthone 7-o β-D-apiofuranosyl-(1-6)-β-D-glucopyranoside and euxanthone-7-o-β-D-glucopyranoside on the basis of spectral (UV, IR, MS, ¹HNMR and ¹³CNMR) and chemical evidences.