Pyrazole–coumarin and pyrazole–quinoline chalcones as potential antitubercular agents

• Published in: Archiv der Pharmazie (Weinheim) 2020-08, Vol.353 (8), p.e2000077-n/a
• Main Authors: Kumar, Gautam, Siva Krishna, Vagolu, Sriram, Dharmarajan, Jachak, Sanjay M.
• Format: Article
• Language: English
• Subjects: antimycobacterial activity; Antitubercular Agents - chemical synthesis; Antitubercular Agents - chemistry; Antitubercular Agents - pharmacology; Chalcones - chemical synthesis; Chalcones - chemistry; Chalcones - pharmacology; Coumarins - chemical synthesis; Coumarins - chemistry; Coumarins - pharmacology; cytotoxic activity; Microbial Sensitivity Tests; Molecular Docking Simulation; Molecular Structure; Mycobacterium tuberculosis - drug effects; pyrazole; Pyrazoles - chemical synthesis; Pyrazoles - chemistry; Pyrazoles - pharmacology; Quinolines - chemical synthesis; Quinolines - chemistry; Quinolines - pharmacology; Software; synthesis
• ISSN: 0365-6233; 1521-4184
• DOI: 10.1002/ardp.202000077

Pyrazole, coumarin, and quinoline are medicinally important moieties. In this study, two series of novel pyrazole–coumarin chalcones and pyrazole–quinoline chalcones were synthesized using multiple‐step reactions. All the synthesized compounds were well characterized using different spectroscopic techniques including 1H and 13C nuclear magnetic resonance, high‐resolution mass spectroscopy, and electrospray ionization–mass spectrometry. The compounds were evaluated for their antitubercular activity against the Mycobacterium tuberculosis H37Rv strain using the microplate Alamar Blue assay, and the minimal inhibitory concentrations (MIC) of the compounds were determined. Among the 32 tested compounds, compounds 3e, 3u, and 7h showed an MIC value of 3.125 µg/ml, and they were found to be nontoxic. Molecular docking studies of the compounds with the enzyme DprE1 revealed the probable mechanism of action. The chalcone derivatives exhibited binding affinity values between −7.047 and −9.353 kcal/mol. ADME parameters were predicted using the QikProp module of the Schrödinger software, and these compounds exhibited good pharmacological and oral absorption properties. In this study, two series of novel pyrazole–coumarin chalcones and pyrazole–quinoline chalcones were synthesized and evaluated for their antitubercular activity against Mycobacterium tuberculosis H37Rv. Among the 32 tested compounds, compounds 3e, 3u, and 7h showed a minimal inhibitory concentration value of 3.125 µg/ml, and they were found to be nontoxic. Molecular docking studies of the compounds with the enzyme DprE1 revealed the probable mechanism of action.