From the leaves of COLUBRINA ASIATICA B RONGEN (Rhamnaceae) two saponins have been isolated and structurally elucidated, mainly by (13)C-NMR-spectroscopic methods, as jujubogenin-3-O-[2-O-acetyl-3-O-(3-O-beta-D-xylopyranosyl-4-O-acetyl-beta-D-glucopyranosyl)-alpha-L-arabinoside] (colubrinoside) and jujubogenin-3-O- [2-O-acetyl -3-O- (2-O- beta -D- xylopyranosyl-beta-D-glucopyranosyl)-alpha-L-arabinoside] (colubrin) respectively. Both saponins inhibit the spontaneous motility of mice, even at low doses (1 mg/ kg), they show an antagonistic effect on amphetamine and exert a synergistic activity on chlordiazepoxide.