OLEANOLIC ACID SAPONINS FROM THE ROOT BARK OF ARALIA TAIBAIENSIS

Five oleanolic acid saponins were isolated from the root bark of Aralia taibaiensis Z.Z.Wang et H.C.Zheng. By spectroscopic and chemical methods, they were identified as araloside A (1), 3-O-α-L-arabinofuranosyl(1→4)6′-O-n-butyl-β-D-glucuronopyranosyl-oleanolic acid-28-O-β-D-glucopyranoside (2), 3-O-α-L-arabinofuranosyl(1→4)-6′-O-ethyl-β-D-glucuronopyra-nosyl-oleanolic acid-28-O-β-D-glucopyranoside (3), stipuleanoside R₂ (4) and 3-O-β-D-glucopyranosyl(1→3)α-L-arabinofuranosyl(1→4)-6′-O-ethyl-β-D-glucuronopyranosyl-oleanolic acid-28-O-β-D-glucopyranoside (5). Saponin 1 and 4 were isolated from the title plant for the first time. 2, 3 and 5 are new compounds and named taibaienoside I, taibaienoside II and taibaienoside III, respectively.