Functional Versatility of Sulfonamide-pyrazole Derivative: From Antibacterial Activity to Metal ion Sensing Aptitude.

In this study, a novel sulfonamide-Schiff base derivative, ethyl (Z)-2-(5-chloro-3-methyl-4-((2-tosylhydrazono) methyl)-1H-pyrazol-1-yl)acetate 6, was synthesized to address sulfonamide resistance and explore its therapeutic potential. The molecular structure was confirmed through comprehensive spectroscopic analyses including FT-IR, 1H & 13C NMR and mass spectrometry, providing strong evidence for the proposed architecture. Antibacterial evaluation revealed that compound 6 pyrazole exhibited notable antibacterial activity against Staphylococcus aureus (inhibition zones up to 1.2 mm), with comparatively moderate activity against Escherichia coli (0.6–0.7 mm). Molecular docking studies demonstrated pronounced binding affinities toward DNA gyrase and β-lactamase, corroborating its observed antibacterial efficacy and suggesting promising therapeutic relevance. Notably, the compound also displayed sensitive and selective chemosensing for Fe3+ (0.27 µM) and Fe2+ (0.12 µM), highlighting its multifunctional profile as both a potent antibacterial agent and a metal ion sensor. These findings indicate that compound 6 is a multifunctional bioactive scaffold and represents a promising lead for further investigation in antimicrobial and chemosensing applications.