3 years ago

Antibacterial combination therapy using Co3+, Cu2+, Zn2+ and Pd2+ complexes: Their calf thymus DNA binding studies

Fatemeh Khosravi, Hassan Mansouri-Torshizi

Four Co(III)-, Cu(II)-, Zn(II)-, and Pd(II)-based potent antibacterial complexes of formula K3[Co(ox)3].3H2O (I), [Cu(bpy)2Cl]Cl.5H2O (II), [Zn(bpy)3]Cl2 (III), and [Pd(bpy)2](NO3)2 (IV) (where ox is oxalate and bpy is 2,2′-bipyridine) were synthesized. They were characterized by elemental analyses, molar conductance measurements, UV–Vis, FTIR, 1H NMR, and 13C NMR spectra. These metal complexes were ordered in three combination series of I + II, I + II + III, and I + II + III + IV. Antibacterial activity was tested for each of these four metal complexes and their combinations against Gram-positive and Gram-negative bacteria. All compounds were more potent antibacterial agents against the Gram-negative than those of the Gram-positive bacteria. The four metal complexes showed antibacterial activity in the order I > II > III > IV and the activity of their combinations followed the order of I + II + III + IV > I + II + III > I + II. CT-DNA binding studies of complex I and its three combinations were carried out using UV–vis spectral titration, displacement of ethidium bromide (EB), and electrophoretic mobility assay. The results obtained from UV–vis studies indicated that all series interact effectively with CT-DNA. Fluorescence titration revealed that the complexes quench DNA-EB strongly through the static quenching procedures. The binding constant (Kb), the Stern–Volmer constant (Ksv), and the number of binding sites (n) were determined at different temperatures of 293, 300, and 310 K, respectively. The calculated thermodynamic parameters supported that hydrogen binding and Van der Waals forces play a major role in association of each series of metal complexes with CT-DNA and follow the above-binding affinity order for the series.

Publisher URL: http://www.tandfonline.com/doi/full/10.1080/07391102.2017.1281171

DOI: 10.1080/07391102.2017.1281171

You might also like
Never Miss Important Research

Researcher is an app designed by academics, for academics. Create a personalised feed in two minutes.
Choose from over 15,000 academics journals covering ten research areas then let Researcher deliver you papers tailored to your interests each day.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.