[Studies on the triterpenoid saponins of the root bark of Aralia taibaiensis].

Four triterpenoid saponins were isolated from the root bark of Aralia taibaiensis Z. Z. Wang et H. C. Zheng. On the basis of their chemical properties and spectral data, they were identified as oleanolic acid-3-O-[beta-D-xylopyranosyl(1-->2)] [beta-D-glucopyranosyl(1-->3)]-beta-D-glucuronopyranoside (1), tarasaponin V (2), 3-O-¿beta-D-xylopyranosyl(1-->2)[beta-D-glucopyranosyl (1-->3)]-6'-O-ethyl-beta-D-glucuronopyranosyl¿-oleanolic acid-28-O-beta-D-glucopyranoside (3) and 3-O-¿beta-D-xylopyranosyl(1-->2) [beta-D-glucopyranosyl(1-->3)] -6'-O-butyl-beta-D-glucuronopyranosyl¿-oleanolic acid-28-O-beta-D-glucopyranoside (4). Compound 1 is a new natural product named taibaienoside VI. 2 was isolated from the title plant for the first time. 3 and 4 are new compounds and named taibaienoside VII and taibaienoside VIII, respectively.