Depicting the binding of furazolidone/furacilin with DNA by multiple spectroscopies, voltammetric as well as molecular docking.

The interaction between DNA and furazolidone/furacillin was investigated using various analytical techniques including spectroscopy and electroanalysis and molecular modelling. With the aid of acridine orange (AO), the fluorescence lifetimes of DNA-AO, DNA-furazolidone/furacillin-AO remained almost the same, which proved that the ground state complex was formed due to furazolidone/furacillin binding with DNA. Circular dichroism spectra and Fourier transform infrared spectroscopy showed that the second structure of DNA changed. Viscosity experiments presented that relative viscosity of DNA was increased with the increasing concentrations of furazolidone and almost unchanged for furacilin. In addition, the results of melting temperature (Tm ), ionic strength, site competition experiments, cyclic voltammetry, and molecular docking all proved the intercalation binding mode for furazolidone and groove binding mode for furacilin. The binding constants (Ka ) obtained from Wolfe-Shimmer equation were calculated as 3.66 × 104 L mol-1 and 3.95 × 104 L mol-1 for furazolidone-DNA and furacilin-DNA, respectively.