Acetyl pyridine-based palladium(II) compounds as an artificial metallonucleases

Abstract

Palladium(II) complexes of type [Pd(Lⁿ)Cl₂] and [Pd(bdt)(Lⁿ)] have been synthesized using 2-acetyl pyridine derivatives(Lⁿ) and benzene-12-dithiol(bdt). The synthesized complexes have been characterized by various analytical techniques like thermo gravimetric analysis, elemental analysis, conductance measurement, and spectroscopic techniques like elemental analysis, mass spectra, absorption spectra, IR, ¹H NMR, energy-dispersive X-ray spectroscopy. The interaction of the complexes with calf-thymus DNA (CT-DNA) has been explored by absorption titration, viscosity measurement methods. Based on the observations, an intercalative binding mode of DNA has been proposed. In order to provide additional evidence for the intercalation mode of binding between the complex and CT-DNA, fluorescence titration experiment was performed. In addition, molecular modeling study has been carried out with the aim of establishing the complex’s binding mode. Antibacterial activity study of the complexes have been screened against pathogenic bacteria such as Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Serratia marcescens, and Pseudomonas aeruginosa. Gel electrophoresis assay demonstrates that all the complexes can cleave the pUC19 plasmid DNA.

Keywords:

• Pyridine derivatives
• antibacterial agents
• intercalation
• artificial metallonuclease

Acknowledgements

The authors are thankful to the Head, Department of Chemistry, Sardar Patel University, Vallabh Vidyanagar, Gujarat, India, for providing the laboratory facilities, U.G.C., New Delhi for providing financial assistance of UGC BSR grant No. C/2013/BSR/Chemistry/59 and “BSR UGC One Time Grant,” vide UGC letter No.F.19-119/2014 (BSR).