Antioxidant activities of three dihydrochalcone glucosides from leaves of Lithocarpus pachyphyllus.

In vitro antioxidant activities of three sweet dihydrochalcone glucosides from the leaves of Lithocarpus pachyphyllus (Kurz) Rehd. (Fagaceae), trilobatin 2"-acetate (1), phloridzin (2) and trilobatin (3), were investigated. The IC50 (50% inhibitory concentration) values for compounds 1-3 of lipid peroxidation in rat liver homogenate were 261, 28, 88 microM, respectively. Compounds 1-3 increased superoxide dismutase (SOD) activity with EC50 (50% effective concentration) values of 575, 167, 128 microM, and glutathione peroxidase (GSH-Px) activity with EC50 values of 717, 347, 129 microM, respectively, and showed only weak DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity.