| Abstract
| - The present study examined the antioxidants present in bitter tea (Ligustrum pedunculare). It wasfound that the crude glycoside fraction strongly protected human low-density lipoprotein (LDL) fromoxidation. Further column chromatography led to purification of eight phenylethanoid or monoterpeneglycosides: lipedoside A-I, lipedoside A-II, lipedoside B-I, lipedoside B-III, lipedoside B-V, lipedosideB-VI, osmanthuside B, and anatolioside. It was found that lipedoside A-I, lipedoside A-II, lipedosideB-V, and lipedoside B-VI were protective, whereas the other four compounds did not protect humanLDL from Cu2+-medicated oxidation. Lipedoside A-I, lipedoside A-II, lipedoside B-V, and lipedosideB-VI also had a scavenging effect on 2,2-diphenyl-1-picrylhydrazyl free radical (DPPH), comparableto that of α-tocopherol. The inhibitory effect of these four phenylethanoid or monoterpene glycosideson oxidation of human LDL and α-tocopherol was dose-dependent at concentrations of 5−40 μM.The present results demonstrate that bitter tea as a beverage contains effective antioxidants thatmay have benefits similar to those of green tea in terms of antioxidant activity. Keywords: Antioxidant; bitter tea; green tea; phenylethanoid gycosides; monoterpene glycosides
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