Novel 2-phenyl-4,5,6,7-tetrahydro[b]benzothiophene analogues as selective COX-2 inhibitors: Design, synthesis, anti-inflammatory evaluation, and molecular docking studies

A series of 2-phenyl-4,5,6,7-tetrahydro[b]benzothiophene derivatives were synthesized and evaluated for in vitro COX inhibitory potential. Within the series, compounds 4a, 4j, 4k, and 4q were identified as potential and selective COX-2 inhibitors with COX-2 IC50 in 0.31-1.40 mu M range; COX-2 selectivity index (SI) = 48.8-183.8 range and they showed percent PGE-2 inhibitory activity in the range of 25.4-46.9. Further, compounds 4a, 4j, 4k and 4q displayed potent anti-inflammatory activity with percentage rise in paw volume ranging from 21.1-30.5 at 180 min, while celecoxib demonstrated 19.6 percentage rise at the same dose at 180 min in carrageenan-induced rat paw edema assay. Cell viability via MTT assay showed no cytotoxicity up to 80 mu M concentrations. Molecular docking study of potent compounds in the series showed Gscore comparable to celecoxib with similar binding orientation for the COX-2 active site which also corroborates the observed in vitro COX-2 inhibition. (C) 2017 Elsevier Ltd. All rights reserved.