Abstract: Two tautomers, G-1 ［1-O-(3′-galloyl)-galloyl-β-D-glucopyranose and 1-O-(4′-galloyl)galloyl-β-D-glucopyranose］ and G-2 ［3-galloyl-gallic acid and 4-galloyl-gallic acid］ were isolated from Quercus variabilis Bl.,together with four pure phenolic compounds: G-3 (1,6-O-digalloyl-β-D-glucopyranose), G-4 (1,2,3,6-O-tetragalloyl-β-D-glucopyranose), G-5 (1-O-galloyl-β-D-glucopyranose) and G-6 (gallic acid methyl ester) respectively. The inhibitory effects of G-1, G-3 and G-4 on some tumor strains, lipid peroxidation and blood platelet aggregation were investigated in vitro.

Key words: Fagaceae