Anti-oxidant constituents from Sedum takesimense

As part of an ongoing search for antioxidants from medicinal plants, 14 phenolic constitutents were isolated from the Korean endemic species Sedum takesimense Nakai. Their structures were determined as 1-(4-hydroxyphenyl)-2-(3,5-dihydroxyphenyl)-2-hydroxyethanone (5), gossypetin-8-O-beta-D-xylopyranoside (10), and 2,6-di-O-galloylarbutin (13) on the basis of spectroscopic analyses (IR, UV, 1D and 2D NMR, HR-MS) and chemical degradation, together with I I previously known phenolics. Two of those (10 and 13) exhibited strong scavenging activities against DPPH and superoxide radicals as well as significant inhibitory effects on lipid peroxidation IC50 14.0 and 10.8 mu M, respectively) and LDL oxidation induced by a metal ion Cu2+ (IC50 5.7 and 3.3 mu M, respectively). (C) 2007 Elsevier Ltd. All rights reserved.