Non-acidic 1,3,4-trisubstituted-pyrazole derivatives as lonazolac analogs with promising COX-2 selectivity, anti-inflammatory activity and gastric safety profile

Abstract

Twelve new compounds of 1,3,4-trisubstituted-pyrazole derivatives possessing two cyclooxygenase-2 (COX-2) pharmacophoric moieties (SO2Me or/and SO2NH2) 11a-c, 12a-c, 13a-c and 14a-c were designed and synthesized to be evaluated for their COX inhibition, anti-inflammatory activity, ulcerogenic liability. All compounds were more selective for COX-2 isozyme and showed good in vivo anti-inflammatory activity. The bisaminosulphonyl derivatives (14a-c) were the most COX-2 selective compounds (S.I. = 9.87, 9.50 and 9.22 respectively) and showed good anti-inflammatory potency (ED50 = 15.06, 42.51 and 50.43 μmol/kg respectively) in comparison with celecoxib (COX-2 S.I. = 8.61, ED50 = 82.2 μmol/kg). Also, compounds 14a-c were less ulcerogenic (ulcer indexes = 2.72–3.72) than ibuprofen (ulcer index = 20.25) and comparable to celecoxib (ulcer index = 2.93). In addition, to explain the preferential (COX-2) inhibitory and selectivity, the designed compounds were subjected to molecular docking studies. It was found that compound 14c with the highest COX-2 activity and selectivity exhibited a binding pattern and interactions similar to that of celecoxib with formation of more hydrogen-bond features.