1,1-Diphenyl-2-picrylhydrazyl Radical Scavenging Compounds of Fraxini Cortex

The radical scavenging effect of the MeOH extract of Fraxini Cortex on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical was examined. The -and n-BuOH-soluble fractions of MeOH extract showed the promising DPPH radical scavenging effects, and further purified by silica gel, Sephadex LH-20 column chromatography, and reversed-phase C-18 MPLC to yield five coumarins, esculetin (1), fraxidin (2), fraxetin (3), fraxidin (fraxin methyl ether) (5), esculin (6), and a secoiridoid oleuropein (4), and a coumarin-secoiridoid escuside (7). Compounds 1, 3, and 4 showed potent DPPH radical scavenging effects, exhibiting values of 14.68, 9.64, and , respectively. Compounds 6 and 7 also showed moderate effects with values of 147.79 and , respectively. L-Ascorbic acid was used as a positive control and exhibited the value of .