Camelliasaponins B1, B2, C1 and C2, new type inhibitors of ethanol absorption in rats from the seeds of Camellia japonica L.

New type inhibitors of ethanol absorption, camelliasaponins B1, B2, C1 and C2, were isolated from the seeds of Camellia japonica L. The structures of camelliasaponins were elucidated on the basis of chemical and physicochemical evidence. The inhibitory effect of camelliasaponins and related saponins on ethanol absorption have been examined, and it was found that the triterpene oligoglycoside structure having an acyl group was essential to exerting the activity.