Chalcone derivatives bearing chromen or benzo[f]chromen moieties: Design, synthesis, and evaluations of anti-inflammatory, analgesic, selective COX-2 inhibitory activities

Thirty-eight chalconederivatives bearing a chromen or benzo[f]chromen moiety were synthesized and evaluated for their anti-inflammatory and analgesic activities. Using an ear edema model, anti-inflammatory activities were observed for compounds 3a-3s (ear inflammation: 1.75-3.71 mg) and 4a-4s (ear inflammation: 1.71-4.94 mg). All compounds also displayed analgesic effects with inhibition values of 66.7-100% (3a-3s) and 96.2-100% (4a-4s). The 12 compounds that displayed excellent anti-inflammatory and analgesic effects were tested for their inhibitory activity against ovine COX-1 and COX-2. Six compounds bearing a chromen moiety were weak inhibitors of the COX-1 isozyme but showed moderate COX-2 isozyme inhibitory effects (IC₅₀s from 0.37 μM to 0.83 μM) and COX-2 selectivity indexes (SI: 22.49-9.34). Those bearing a benzo[f]chromen moiety were more selective toward COX-2 than those bearing a chromen moiety with IC₅₀s from 0.25 μM to 0.43 μM and COX-2 selectivity indexes from SI: 31.08 to 20.67.