Synthesis and biological evaluation of some pyrazolylpyrazolines as anti-inflammatory–antimicrobial agents

A new series of pyrazolylpyrazolines (5a–k) was synthesized by the reaction of appropriate chalcones (3a–k) with 4-hydrazinobenzenesulfonamide hydrochloride (4) in ethanol. All the newly synthesized target compounds (5a–k) were screened for their anti-inflammatory activity using carrageenan-induced rat paw edema assay. Compounds 5g and 5j showed pronounced anti-inflammatory activity comparable to the reference standard nimesulide, whereas, compounds 5b, 5d and 5h displayed good anti-inflammatory activity. Additionally, the synthesized compounds were evaluated for their in vitro antimicrobial activity against two Gram-positive bacteria and two Gram-negative bacteria. Four compounds 5c, 5h–5j showed good broad spectrum activity against all the tested Gram-positive and Gram-negative bacterial strains. Compound 5j could be identified as the most biologically active member within this study with an interesting dual anti-inflammatory and antibacterial profile.

Graphical abstractA series of pyrazolylpyrazolines with vicinal diaryl substitution pattern on the pyrazole as well as pyrazoline nucleus was synthesized. One of the compounds showed interesting dual anti-inflammatory and antibacterial profile.Figure optionsDownload full-size imageDownload as PowerPoint slide