Abstract: Five saikosaponins were isolated from the roots of Bupleurum scorzonerifolium Willd. A new saikosaponin was elucidated as the 3β, 16α, 23, 28-tetrahydroxy-oleana-ll, 13( 18)-dien-3-O- β-D-glucopyranosyl- ( 1 ~ 6 )- [ a-L-rhamnopyranosyl- ( 1 ~ 4 ) ] -β-D-glucopyranoside on the basis of spectral analysis and named as the saikosaponin s. The other four saikosaponins were determined as the saikosaponin a, saikosaponin c, saikosaponin bi and saikosaponin b2.

Key words: Bupleurum scorzonerifolium, triterpenoid saponin, saikosaponin s