Synthesis, biological evaluation and docking analysis of 3-methyl-1-phenylchromeno[4,3-c]pyrazol-4(1H)-ones as potential cyclooxygenase-2 (COX-2) inhibitors

Abstract

As a part of our continued efforts to discover new COX inhibitors, a series of 3-methyl-1-phenylchromeno[4,3-c]pyrazol-4(1H)-ones were synthesized and evaluated for in vitro COX inhibitory potential. Within this series, seven compounds (3a–d, 3h, 3k and 3q) were identified as potential and selective COX-2 inhibitors (COX-2 IC₅₀’s in 1.79–4.35 μM range; COX-2 selectivity index (SI) = 6.8–16.7 range). Compound 3b emerged as most potent (COX-2 IC₅₀ = 1.79 μM; COX-1 IC₅₀ >30 μM) and selective COX-2 inhibitor (SI >16.7). Further, compound 3b displayed superior anti-inflammatory activity (59.86% inhibition of edema at 5 h) in comparison to celecoxib (51.44% inhibition of edema at 5 h) in carrageenan-induced rat paw edema assay. Structure–activity relationship studies suggested that N-phenyl ring substituted with p-CF₃ substituent (3b, 3k and 3q) leads to more selective inhibition of COX-2. To corroborate obtained experimental biological data, molecular docking study was carried out which revealed that compound 3b showed stronger binding interaction with COX-2 as compared to COX-1.

Keywords

• 3-Methyl-1-phenylchromeno[4,3-c]pyrazol-4(1H)-ones;
• Cyclooxygenase-2;
• Anti-inflammatory;
• Molecular docking

Authors

• Jagdeep Grover^a,
• Vivek Kumar^b,
• M. Elizabeth Sobhia^b,
• Sanjay M. Jachak^{a, , ,}

• ^a Department of Natural Products, National Institute of Pharmaceutical Education and Research, Sector-67, S.A.S. Nagar (Mohali) 160062, Punjab, India
• ^b Department of Pharmacoinformatics, National Institute of Pharmaceutical Education and Research, Sector-67, S.A.S. Nagar 160062, Punjab, India

Sanjay Corresponding author. Tel.: +91 172 2214683; fax: +91 172 2214692.

• Supplementary data