Inhibitory Effects of Methanol Extract, Phenolic Acids and Flavonoids from the Leaves of Eucalyptus darylmpleana agianst 1,1-Diphenyl-2-picrylhydrazyl Radical

The inhibitory effects of the leaves of Eucalyptus darylmpleana (Myrtaceae) on the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical was examined. The scavenging effect of the ethyl acetate fraction of Eucalyptus darylmpleana leaves on DPPH radical was stronger than the other fractions, and further purified by silica gel and Sephadex LH-20 column chromatography. 3, 4-Dihydroxybenzoic acid, gallic acid, quercetin, quercetin 3-O-α-Lrhamnoside, quercetin 3-O-β-D-glucoside and quercetin 3-O-rutinoside were isolated and elucidated by spectroscopic data. Among these components, gallic acid and quercetin 3-O-α-L-rhamnoside exhibited potent scavenging activities on DPPH radical with IC50 values of 6.02 and 5.54 μM, respectively. KCI Citation Count: 5