DNA Interaction Studies of an Antiviral Drug, Ribavirin, Using Different Instrumental Methods

Interaction of ribavirin with CT-DNA was investigated by emission, absorption, circular dichroism, and viscosity studies to determine the binding mode and binding constant of this drug with DNA. The calculated binding constant, K-b, obtained from UV-vis absorption studies was 4.6 x 10(3) M-1. In fluorimetric studies, the enthalpy (Delta H<0) and entropy (Delta S>0) of the reaction between ribavirin and CT-DNA showed a hydrophobic interaction. In addition, in the circular dichroism spectrum, the drug induces a B -> A structural transition of CT-DNA. These results demonstrate that ribavirin interacts with CT-DNA via the groove binding mode. It was observed that the drug has ability to cleave supercoiled plasmid DNA.