Synthesis and biological evaluation of 2-aroylbenzofurans, rugchalcones A, B and their derivatives as potent anti-inflammatory agents

An efficient synthesis of 2-aroylbenzofurans, rugchalcones A, B and their derivatives was accomplished in excellent yields by the Rap-Stoermer reaction between substituted salicylaldehydes and phenacyl bromides. Later their anti-inflammatory effects were evaluated in lipopolysaccharide (LPS)-induced RAW-264.7 macrophages. The compounds were exhibited exceptional potency against inflammatory mediated NO production with no cytotoxicity at 10 μM concentration and IC50 values are found in the range from 0.75 to 13.27 μM. Among the 2-aroylbenzofurans prepared in this study, compounds 4 (99.6%; IC50=0.57), rugchalcone B (2) (99.3%; IC50=4.13), 7 (96.8%; IC50=1.90) and 8 (74.3%; IC50=0.99) were showed the maximum inhibitory activity. This study suggests that compounds 2, 4, 7 and 8 which are having 4-hydroxyphenyl group and/or hydroxy (-OH) group at 5- and/or 6-position of benzofuran motif could be considered as a promising scaffolds for the further development of iNOS inhibitors for potential anti-inflammatory applications.