Synthesis, Spectral Identification, and Antibacterial Activity of New Schiff Base Curcumin Derivatives

Abstract

This work describes the synthesis of new Schiff bases that link curcumin with five third-generation cephalosporin antibiotics (cefotaxime, ceftazidime, ceftriaxone, cefixime, and cefdinir), using both mono- and bis-substituted curcumin derivatives. The synthesized compounds were characterized by IR and ¹H and ¹³C NMR spectroscopy and elemental analysis. Their bioactivity was evaluated against S. aureus, P. aeruginosa, and E. coli. Molecular docking was performed to assess the binding affinities of the products to the penicillin-binding proteins PBP1a, PBP1b, PBP4, and PBP6, using some of the synthesized curcumin-derivatives as representative examples. Toxicity prediction indicated potential immunotoxicity, with estimated median lethal doses (LD₅₀) ranging from 1000 to 800 mg/kg.