Synthesis, Characterization, and Antimicrobial Evaluation of Schiff Base-mixed Ligand Complexes with Divalent Metal Ions Derived from Amoxicillin and Vanillin/Nicotinamide.

Introduction: This study focuses on the development of novel antimicrobial agents. A Schiff base ligand, 6-(2-(4-hydroxy-3-methoxybenzylideneamino)-2-(4-hydroxyphenyl)acetamido)-3,3-dimethyl-7-oxo- 4-thia-1-azabicyclo [3.2.0] heptane-2-carboxylic acid, synthesized through the condensation of amoxicillin and vanillin in methanol, served as the foundation. Polydentate mixed ligand complexes were then formed by reacting the Schiff base with metal ions (Fe(II), Co(II), Ni(II), Cu(II), and Zn(II)) and nicotinamide in specific ratios.

Methods: Characterization involved various techniques, such as H-NMR, FT-IR, UV-Vis, and elemental analysis for the ligand, and Atomic Absorption, FT-IR, UV-Vis, magnetic susceptibility, and conductance measurements for the Schiff base-metal ion complexes.

Results: Quantum chemical features of both ligands and metal complexes were computed, refining their electronic and molecular structures theoretically. Antimicrobial activity against , and was assessed for the starting materials, ligands, and synthesized complexes, revealing significant effects on certain species. binding modes with (PDB ID: 5iq9) were determined through molecular docking.

Conclusion: This study underscores the potential applications of the Schiff base ligands and their metal complexes in developing new antimicrobial agents.