Metformin-Derived Water-Soluble Cobalt Complexes: Thermal, Spectroscopic, DNA Interaction, and Molecular Docking...

Area of Science:

• Coordination Chemistry
• Materials Science
• Biophysical Chemistry

Background:

• Metformin (Metf) is a widely used antidiabetic drug.
• Cobalt (II) complexes with nitrogen-containing ligands are of interest for their diverse applications.
• Understanding metal-ligand interactions is crucial for designing novel functional materials.

Purpose of the Study:

• Synthesize and characterize novel water-soluble cobalt (II) complexes.
• Investigate the stability, thermal degradation, and DNA interaction of these complexes.
• Evaluate their potential as DNA binding agents and nuclease agents.

Main Methods:

• Synthesis and characterization using analytical and spectral techniques.
• Quantum chemical calculations (HOMO-LUMO energies) for stability analysis.
• Thermal analysis (Coats-Redfern method) for kinetic parameters.
• Spectroscopic (absorption, emission) and viscosity studies for DNA interaction.
• Nuclease activity assay and molecular docking studies.

Main Results:

• Three novel water-soluble cobalt (II) complexes, [Co(metf)(o-phen)2]Cl2 (1), [Co(metf)(opda)2]Cl2 (2), and [Co(metf)(2,2'-bipy)2]Cl2 (3), were successfully synthesized and assigned octahedral geometry.
• Complexes exhibit good stability, with kinetic parameters determined from thermal degradation studies.
• DNA interaction studies indicate groove binding mode with significant binding constants (Kb ~10^4 M^-1) and quenching constants (Ksv).
• Complexes demonstrated nuclease activity against pUC19 DNA in the presence of H2O2, with complex 2 showing the highest binding affinity in molecular docking simulations.

Conclusions:

• The synthesized cobalt (II) complexes are stable, water-soluble, and exhibit octahedral geometry.
• These complexes effectively bind to DNA through the groove binding mechanism.
• The complexes possess nuclease activity, suggesting potential applications in DNA cleavage and related fields.
• Complex 2 shows promising binding affinity to B-DNA, warranting further investigation.