Synthesis and biological activity of halophenols as potent antioxidant and cytoprotective agents

A series of new bromophenols and chlorophenols were prepared by a practical route. The in vitro antioxidative activity of the halophenols was evaluated by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging assay, and their cytoprotective activity was also tested on hydrogen peroxide (H2O2)-induced injury in human umbilical vein endothelial cells (HUVEC). All halophenols tested displayed moderate to good DPPH radical-scavenging activity, and two bromophenols, 2,3'-dibromo-4,5,6'-trihydroxydiphenyl-methanone (16c) and 2,3-dibromo-4,5-dihydroxydiphenylmethanone (17c) exhibited high protective activity against H2O2-induced injury in HUVEC with EC50 values of 0.4 and 0.8 mu M, respectively. The preliminary structure-activity relationships of these compounds were also investigated in order to determine the essential structures required for their bioactivities. (C) 2010 Elsevier Ltd. All rights reserved.