Synthesis, characterization and in vitro DNA binding studies of a new copper(II) complex containing an antiviral drug, valganciclovir

• Published in: Journal of coordination chemistry Vol. 70; no. 2; pp. 201 - 222
• Main Authors: Shahabadi, Nahid, Pourfoulad, Mehdi, Taherpour, Avat (Arman)
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 17.01.2017; Taylor & Francis Ltd
• Subjects: Binding; Biotechnology; COPPER COMPOUNDS; Copper(II)-antiviral drug complex; Deoxyribonucleic acid; DFT calculations; DNA; DNA binding; Docking; Drugs; FABRICATION; groove binding; hydrophobic forces; Synthesis; valganciclovir; Viability; Viscosity
• ISSN: 0095-8972; 1029-0389
• DOI: 10.1080/00958972.2016.1257790

A new complex, [Cu(valcyte) 2 (NO 3 ) 2 ], in which valcyte served as a valganciclovir drug, was synthesized and characterized by different physicochemical methods. Optimization of ligand structures and their complexes with Cu 2+ were performed by semi-empirical and DFT methods. Binding interaction of this complex with calf-thymus DNA (ct-DNA) was explored by emission, absorption, circular dichroism and viscosity techniques. Additionally, cell line targeting was studied and cytotoxic effects of [Cu(valcyte) 2 (NO 3 ) 2 ] (0.0-160 μg) on AGS and MCF-7 cell lines were reported. Percentage of Cell Viability and Apoptotic Index were assessed. The complex displayed significant binding properties to ct-DNA. Undertaking fluorometric studies, the binding mode of the complex with ct-DNA was explored utilizing Hoechst as a fluorescence probe, indicating the binding to be of groove mode. The DNA viscosity altered slightly in presence of the complex. Enthalpy and entropy changes during the interaction showed that the process is endothermic, with the complex mainly bound to ct-DNA by hydrophobic attraction. Values of ΔG revealed a spontaneous reaction between DNA and the complex. Optimized docked model of DNA-complex mixture confirmed the experimental results. The results of MMFF94 calculations indicated stability of [Cu(valcyte) 2 (NO 3 ) 2 ] after docking with the modeled DNA profile, as compared to the DNA profile and valganciclovir results before the docking process. Cytotoxicity studies showed that an increase in [Cu(valcyte) 2 (NO 3 ) 2 ] may result in a significant decrease in cell viability and increase apoptosis index in the treated cells, as compared to valganciclovir treated cells (p < 0.05). The findings further showed that [Cu(valcyte) 2 (NO 3 ) 2 ] has potential for use in cancer therapy.