Understanding the Binding Mechanism of a Pyrazino[1,2‐a]indole Derivative with Calf Thymus DNA

Abstract This work was focused on understanding the interaction mechanism of pyrazino[1,2‐ a ]indole derivative in calf thymus DNA (ctDNA) using various spectroscopy and computational techniques. The UV‐Vis absorption result shows that the binding interaction of pyrazino[1,2‐ a ]indole derivative in ctDNA complex may be in the non –covalent form and the binding associate constant K a value was estimated 7.06×10 3  L mol −1 at 297 K. The fluorescence emission spectroscopy analysis suggested that pyrazino[1,2‐ a ]indole derivative quenching mechanism in ctDNA mainly due to the static nature and thermodynamical parameter analysis implied the binding of pyrazino[1,2‐ a ]indole derivative in ctDNA mainly due to hydrophobic force. Forster resonance energy transfer analysis was also calculated and the r =2.1 nm. Circular dichroism spectra conclude that there is a change in the secondary structural region of ctDNA due to an interaction with pyrazino[1,2‐ a ]indole derivative. Together with the molecular docking studies, hydrophobic nature of the interaction of pyrazino[1,2‐ a ]indole derivative with ctDNA might be deduced.