Bioactive saponins and glycosides. V. Acylated polyhydroxyolean-12-ene triterpene oligoglycosides, camelliasaponins A1, A2, B1, B2, C1, and C2, from the seeds of Camellia japonica L.: structures and inhibitory activity on alcohol absorption.

Acylated polyhydroxyolean-12-ene triterpene oligoglycosides, camelliasaponins A1, A2, B1, B2, C1, and C2, were isolated from the seeds of Camellia japonica L. The structures of six camelliasaponins were elucidated on the basis of chemical and physicochemical evidence. Camelliasaponins B1, B2, C1, and C2 were found to exhibit inhibitory activity on ethanol absorption. By comparison of the inhibitory activities for camelliasaponins with those for desacyl-camelliasaponins, acyl groups such as the angeloyl or tigloyl group were found to be essential to exerting the activity.