Benzenesulfonamide bearing pyrazolylpyrazolines: synthesis and evaluation as anti-inflammatory–antimicrobial agents

Abstract

Two novel series of pyrazolylpyrazolines (4a–i and 5a–i) bearing benzenesulfonamide moiety at position-1 of pyrazole were synthesized by the reaction of appropriate chalcones (3a–i) with hydrazine hydrate or 4-hydrazinobenzenesulfonamide hydrochloride in refluxing ethanol/THF containing catalytic amount of acetic acid. All the newly synthesized target compounds (4a–i and 5a–i) were screened for in vivo anti-inflammatory (AI) activity using carrageenan-induced rat paw edema assay. In addition, all 18 synthesized compounds were evaluated for in vitro antibacterial activity against two Gram-positive and two Gram-negative bacteria, and in vitro antifungal activity against two fungal strains. The results revealed that seven compounds (4b–e, 4g, 5e, and 5i) displayed excellent AI activity (≥70 % inhibition) including two compounds (4b and 4e) which showed same level of AI activity as that of the standard drug indomethacin (78 % inhibition) 3 h after carrageenan injection. In addition, most of the compounds exhibited moderate antibacterial activity against Gram-positive bacteria as well as moderate antifungal activity against the tested fungi. Two novel series of pyrazolylpyrazolines bearing benzenesulfonamide moiety at position-1 of pyrazole were synthesized and screened for their potential to act as dual anti-inflammatory–antimicrobial agents. Some of the target compounds showed excellent AI activity comparable to the standard drug indomethacin.