Vol. 7, Issue 2, Part C (2025)

Background: Chalcones and their heterocyclic derivatives, such as pyrazolines and triazoles, are widely recognized for their diverse biological activities. Curcumin, a natural chalcone analogue, has inspired the design of new molecules with enhanced antimicrobial potential.

Methods: Four chalcone derivatives were synthesized from a curcumin-inspired starting scaffold using piperidine as an organocatalyst in a Claisen-Schmidt condensation. Cyclization of these chalcones with phenylhydrazine afforded four dihydropyrazoline derivatives. Two 1,2,3-triazole conjugates were subsequently obtained via copper(I)-catalyzed azide-alkyne cycloaddition (click chemistry). All compounds were structurally characterized by ¹H NMR, ¹³C NMR, and IR spectroscopy. Antimicrobial activity was assessed against Escherichia coli, Staphylococcus aureus, and Klebsiella pneumoniae, while antifungal activity was evaluated against Aspergillus niger.

Results: The synthesized compounds demonstrated notable antibacterial and antifungal activity. Several derivatives exhibited potent inhibition of bacterial growth, with IC₅₀ values as low as 1.25 μM. The triazole derivatives showed superior antifungal activity, producing inhibition zones up to 4 cm against A. niger. Chalcone and pyrazoline intermediates retained moderate antibacterial potency, while triazole conjugation markedly enhanced antifungal effects.

Conclusion: A series of curcumin-inspired chalcones, dihydropyrazolines, and triazoles were synthesized and evaluated for antimicrobial potential. The results suggest that molecular hybridization and click chemistry represent effective strategies to improve biological activity. In particular, 1,2,3-triazole derivatives emerged as promising antifungal scaffolds, warranting further exploration for the development of novel antimicrobial agents.