DNA interaction studies of a platinum (II) complex containing an antiviral drug, ribavirin: The effect of metal on DNA binding

The water-soluble Pt (II) complex, [PtCl (DMSO)(N4N7-ribavirin)]· H2O (ribavirin is an antiviral drug) has been synthesized and characterized by physico-chemical and spectroscopic methods. The binding interactions of this complex with calf thymus DNA (CT-DNA) were investigated using fluorimetry, spectrophotometry, circular dichroism and viscosimetry. The complex binds to CT-DNA in an intercalative mode. The calculated binding constant, Kb, was 7.2 × 105 M−1. In fluorimetric studies, the enthalpy (ΔH < 0) and entropy (ΔS > 0) changes of the reaction between the Pt (II) complex with CT-DNA showed hydrophobic interaction. In addition, CD study showed stabilization of the right-handed B form of CT-DNA. All these results prove that the complex interacts with CT-DNA via intercalative mode of binding. In comparison with the previous study of the DNA interaction with ribavirin, these results show that platinum complex has greater affinity to CT-DNA.

In this study, an attempt has been made to study the interaction of a platinum (II) complex containing an antiviral drug, ribavirin, with CT-DNA.Figure optionsDownload as PowerPoint slideHighlights
► Accelerate the availability of new drugs to reposition drugs approved for other indications as anticancer agents.
► Search for new molecular structure containig an antiviral drug which exhibit effective antitumor activities.
► To investigate the effects the metal center on the structure and conformation of DNA.
► Several spectroscopic techniques have been used in this research.