Abstract: To search for new and bioactive compounds from traditional Chinese medicines, a new glycoside,3-O-[a-L-rhamnopyranosyl-(1®3)- (n-butyl-b-D-glucopyranosiduronate)]-28-O-b-D-glucopyranosyl oleanolic acid (1),was isolated from the roots of Cyathula officinalis Kuan, along with 3-O-(methyl-b-D-glucopyranosiduronate)-28-O-b-D-glucopyranosyl oleanolic acid (2), 3-O-b-D- glucopyranosyl oleanolic acid (3), 3-O-b-D-glucuronopyranosyl oleanolic acid (4), 3-O- [a- L - rhamnopyranosyl-(1®3)-(b-D-glucuronopyranosyl)] oleanolic acid (5), 3-O-(b-D- glucuronopyranosyl)-28-O-b-D-glucopyranosyl oleanolic acid (6), 28-O-b-D- glucuronopyranosyl -(1®4)-b-D- glucopyranosyl hederagenin (7), 3-O-[a-L-rhamnopyranosyl- (1®3)-b-D- glucuronopyranosyl] -28-O-b-D-glucopyranosyl oleanolic acid (8), and 3-O-[b-D- glucopyranosyl -(1®2)-a-L- rhamnopyranosyl-(1®3)-b-D-glucuronopyranosyl]-28-O-b-D-glucopyranosyl oleanolic acid (9). The structures of these compounds were determined based on spectral and chemical evidence. The 50 per cent growth-inhibiting (GI50) of compounds 1 and 5 against MDA-MB-231 (a human breast cancer cell line) was 3.44 ´ 10–4 and 4.66 ´ 10–4 mol/L, respectively.

Key words: Cyathula officinalis Kuan, cytotoxic activity, glycoside, oleanolic acid.