• Korean Journal of Pharmacognosy
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• v.28 no.4
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• pp.179-184
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• 1997

To search for useful antioxidants from plant materials, we investigated the antioxidative activity in the methanol extracts of 30 Chinese medicinal plants using DPPH method. The highest activity $(RC_{50}:\;12\;{\mu}g)$ was showed in the methanol extract of Rosa rugosa, followed by Potentilla fruticosa $(14\;{\mu}g)$, P. fragarioides $(16\;{\mu}g)$. And Geum aleppicum $(18\;{\mu}g)$. From the leaves of R. rugosa, two antioxidative compounds were isolated by a bioassay guided purification and identified as isoquercitrin and ${\beta}-glucogallin$ on the basis of $^1H-,\;^{13}C-\;NMR$, and FAB-MS data. ${\beta}-Glucogallin$ is the first report in this plant. The DPPH radical scavenging activity of ${\beta}-glucogallin\;(RC_{50}:\;8.5\;{\mu}g)$ was more effective than those of ${\alpha}-tocopherol\;(12\;{\mu}g)$ and BHA $(14\;{\mu}g)$.