Two new 2,3-seco triterpenoids from Rubus pirifolius Smith / 药学学报

Eight compounds were isolated from the ethyl acetate fraction of the 80% aqueous ethanol extract of the roots and stems of Rubus pirifolius Smith by AB-8 macroporous resin, silica gel, ODS, Sephadex LH-20 column chromatography, and semi-preparative HPLC. Their structures were identified by spectral analysis such as 1D/2D NMR, MS, UV, IR and by comparison with literature information as rubussecotriterpene A (1), rubussecotriterpene B (2), cecropiacic acid (3), cecropiacic acid 3-methyl ester (4), alphitolic acid (5), betulinic acid (6), betulin (7), and obtusalin (8). Compounds 1 and 2 are new compounds, and compounds 3-8 were isolated from this plant for the first time.