Antioxidative Activity of Prunus sargentii Outer Bark Extractives

The outer bark of Prunus sargentii was collected, air-dried and extracted with 70% aqueous acetone. Then it was successively partitioned with n-hexane, dichloromethane ( $CH_2Cl_2$ ), ethyl acetate (EtOAc) and $H_2O$ . From the EtOAc soluble fraction, four compounds were isolated by the repeated Sephadex LH-20 column chromatography. The isolated compounds were determined as (+)-catechin (1), (-)-epicatechin (2), taxifolin (3), and neosakuranin (4) by the spectroscopic analysis including $^1H$ , $^{13}C$ -NMR, and 2D-NMR spectrometers. The antioxidative activities on the isolated compounds and the separated fractions were evaluated by DPPH radical scavenging assay. The crude, EtOAc, and $H_2O$ soluble fractions indicated good antioxidative potential compared to the $CH_2Cl_2$ and n-hexane soluble fractions.