Antioxidants in Leaves of Rosa rugosa

해당화(Rosa rugosa) 잎의 항산화물질

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 $(14\;{\mu}g)$.