Synthesis, crystal structures and CT-DNA/BSA binding properties of Co(III) and Cu(II) complexes with bipyridine Schiff base ligand

• Published in: Inorganica Chimica Acta 2022-03, Vol.532, p.120751, Article 120751
• Main Authors: Chang, Ling-ling, Yang, Jie, Lai, Shi-qi, Liu, Xiang-rong, Yang, Zai-wen, Zhao, Shun-sheng
• Format: Article
• Language: English
• Subjects: Antibacterial activity; Binding; BSA; Complex; Coordination compounds; Crystal structure; CT-DNA; E coli; Exothermic reactions; Fluorescence; Grooves; Hydrogen bonds; Hydrophobicity; Imines; Ligands; Molecular docking; Pseudomonas aeruginosa; Single crystals; Spectrum analysis; Transition metal compounds
• ISSN: 0020-1693; 1873-3255
• DOI: 10.1016/j.ica.2021.120751

[Display omitted] •Crystal structures of Co(II) and Cu(II) complexes with bipyridine Schiff base ligand were confirmed by single crystal XRD.•TG-DTG results indicated that two complexes all possessed high thermal stabilities.•The interactions of complexes with CT-DNA/BSA were studied by UV–vis, fluorescence spectra and microcalorimetry.•The binding modes of complexes with CT-DNA/BSA were studied by molecular docking.•The antibacterial activities of complexes against four kinds of bacteria were discussed. A novel bipyridine Schiff base ligand C12H9ClN4O (HL) and its two transition metal complexes [CoL2]NO3⋅H2O (1) and CuL2⋅CH3OH (2) have been synthesized. Their structures have been characterized by single crystal XRD, showing that 1 and 2 belong to triclinic systems and P-1 space groups. TG-DTG results indicate that 1, 2 and HL all possess high thermal stabilities. The interactions of 1, 2 and HL with calf thymus DNA (CT-DNA) have been investigated by UV–vis spectra and fluorescence spectra, illustrating each complex binds to CT-DNA in an intercalation mode and HL interacted with CT-DNA through groove binding mode. Fluorescence spectroscopy has been used to determine the interactions of 1, 2 and HL with BSA, showing 1, 2 and HL can bind with BSA in static mechanism. Microcalorimetry measurements indicate that the processes of 1, 2 and HL interacting with CT-DNA and BSA are all exothermic, and the reactions complete within 35 min. The molecular docking shows that each compound binds to CT-DNA and BSA mainly through hydrophobic interactions and hydrogen bonds. In addition, 2 exhibits excellent antibacterial activities against Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis and Escherichia coli.