Macrocyclic Schiff base complexes as potent antimicrobial agents: Synthesis, characterization and biological studies

Area of Science:

• Coordination Chemistry
• Macrocyclic Chemistry
• Materials Science

Background:

• Macrocyclic ligands offer unique structural properties for metal complexation.
• Tetraaza-dibenzenacyclooctaphane ligands provide a versatile scaffold for novel coordination compounds.

Purpose of the Study:

• To synthesize and characterize novel metal complexes of Cu(II), Co(II), Zn(II), and Ni(II) with a specific macrocyclic ligand.
• To evaluate the antimicrobial efficacy of the synthesized macrocyclic complexes.
• To investigate the in-vitro hemolytic and DNA binding interactions of these metal complexes.

Main Methods:

• Template synthesis methodology for macrocyclic metal complexes.
• Physicochemical and spectroscopic characterization (IR, ESI-MS, ESR, UV-Vis, CHN, NMR, molar conductance, magnetic moment).
• Agar well diffusion assay for antimicrobial activity.
• In-vitro hemolytic assays and DNA binding studies.
• Density Functional Theory (DFT/TD-DFT) and Gaussian09W for structural and quantum chemical analysis.

Main Results:

• Successful synthesis and full characterization of Cu(II), Co(II), Zn(II), and Ni(II) macrocyclic complexes.
• Demonstrated antimicrobial activity of the synthesized complexes against various pathogens.
• Detailed analysis of DNA binding modes and hemolytic activity, providing insights into their biological interactions.
• DFT calculations elucidated structural parameters and electronic properties.

Conclusions:

• The synthesized macrocyclic metal complexes exhibit significant antimicrobial potential.
• DNA binding and hemolytic studies indicate potential mechanisms for biological activity.
• Computational studies provide valuable insights into the structure-activity relationships of these novel complexes.