In the course of our screening to find anti-alcoholic active principles contained in Occidental herbs, we have found that the methanolic extract from Laurel (Laurus nobilis, leaves) potently inhibited blood ethanol elevation in ethanol-loaded rats, and HCl/EtOH-induced gastric lesions in rats. Through a bioassay-guided separation, various sesquiterpenes having an α-methylene-γ-butyrolactone moiety, costunolide (1), dehydrocostus lactone (2), zaluzanin D (3), reynosin (4), santamarine (5), 3α-acetoxyeudesma-1,4(15),11(13)-trien-12,6α-olide (6), and 3-oxoeudesma-1,4,11(13)-trien-12,6α-olide (7), were isolated as ethanol absorption inhibitors together with three new sesquiterpenes, baynols A (11), B 12-acetate (12), and C (13), whose structures were determined on the basis of chemical and physicochemical evidence. Moreover, 1 and 2 showed potent suppressive activity on HCl/EtOH-induced gastric lesion. In order to characterize the structure-requirements for the inhibition of ethanol absorption, several reduction products and amino acid adducts of the α-methylene-γ-butyrolactone moiety were synthesized from 2 and the inhibitory activities of these synthetic derivatives were examined. These results indicated that the γ-butyrolactone or γ-butyrolactol moiety having α-methylene or α-methyl group was essential for the inhibitory activity on ethanol absorption and gastric lesions. In the study of their action mechanisms, the inhibitory effects of 1 on ethanol absorption were found to be based on inhibition of gastric emptying and dilution of the ethanol concentration by the increased gastric fluid. Continuously, we found the hepatoprotective effect of methanolic extract from Linden (Tilia argentea, flower and leaves) on D-galactosarnine/lipopolysaccharide-induced liver injury in mice. Through a bioassay-guided separation, tiliroside (14) was identified as a principal active compounds together with 6 flavonol glycosides. The active segment of 14 was found to be kaempferol 3-O-β-D-glucopyranoside (16) and the amount of 14 in various Tilia species were determined.