Antioxidative glucosides from the fruits of Ligustrum lucidum.

The ethanol extract of the fruits of Ligustrum lucidum was shown to have inhibitory effects on the hemolysis of red blood cells induced by 2,2'-azo-bis-(2-amidinopropane) dihydrochloride. Bioassay-guided analysis led to the isolation of ten secoiridoid glucosides. Two of them were new, lucidumosides C and D. Their structures were elucidated by spectroscopic methods. The other eight compounds were identified as oleoside dimethyl ester, ligustroside, oleuropein, nuezhenide, isonuezhenide, neonuezhenide, lucidumoside A and lucidumoside B. Five compounds, oleoside dimethyl ester, oleuropein, neonuezhenide, lucidumoside B and lucidumoside C, exhibited strong antioxidant effect against hemolysis of red blood cells induced by free radicals.