Pyrazole-Triazole Schiff Bases: Hybrid Molecular Frameworks with Promising Antimicrobial Activity

A new series of Schiff base was synthesized via acid-catalyzed condensation of 1,3-diphenyl-1H-pyrazole-4-carbaldehydes with 4H-1,2,4-triazol-4-amine. The structures of the compounds were confirmed by 1H and 13C NMR spectroscopy. Antimicrobial screening revealed that nitro and bromo substituted derivatives exhibited the most potent antibacterial and antifungal activities, with minimum inhibitory concentrations comparable to ciprofloxacin and fluconazole. Structure-activity relationship (SAR) analysis indicated that electron-withdrawing substituents significantly enhanced biological activity, while methoxy-substituted analogues displayed moderate efficacy. Molecular docking studies against bacterial DNA gyrase (PDB ID: 1KZN) demonstrated strong binding affinities (from –8.8 to –9.4 kcal/mol) and stable interactions with active-site residues, corroborating the experimental findings. Collectively, these results establish pyrazole–triazole Schiff bases as promising antimicrobial scaffolds, providing a rational basis for future pharmacological development and structural optimization.