Antioxidative Activity of Prunus sargentii Outer Bark Extractives

Abstract

ABSTRACT 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 2 Cl 2 ), ethyl acetate (EtOAc) and H 2 O. 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 1 H, 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 2 O soluble fractions indicated good antioxidative potential compared to the CH 2 Cl 2 and n-hexane soluble fractions. Keywords : Prunus sargentii, bark, EtOAc fraction, neosakuranin, antioxidant 1. INTRODUCTION Prunus sargentii Rehder (Rosaceae) is a na-tive cherry tree to Korea, Japan and Sakhalin (Russia). This is a deciduous tree that grows 6∼8 m in height. The crown spreads to a width of 6∼8 m and can tolerate wind, but not air pollution[1]. The tree is suitable for use as a roadside tree. The bark has been used for the treatment of inflammatory or skin diseases. The main constituents of the species are taxifolin, naringenin, pinostobin including sakuranin[1] and the domestic previous works have reported antioxidant, immunosuppression and tyrosinase inhibition activities on the heartwood extractives of Prunus sargentii[1,2]. However, they have not studied on the chemical constituents and bi-ological activities of the bark which can have rather the higher functional potential. Thus, this work was to carried out to study the chemical constituents and antioxidative ac-tivity of the outer bark to evaluate the bioactive potential for the functional uses.