Hydroxyl Radical Reactivity with Cytosine and Thymine: A Computational Study

Addition of hydroxyl radical (OH) at the different sites of cytosine and thymine were studied at the different levels of theory of the density functional theory (DFT). All the molecular geometries were optimized at B3LYP, B3PW91, WB97XD, and MPW1PW91 methods with 6-31G (d,p) basis set. The binding energies at the different sites of these two DNA bases were calculated at all the mentioned levels of theory in gas phase and also in different solvents of dielectric constant varying from lower to higher values. The dependence of binding energies in water, methanol, ethanol, acetone, toluene and benzene reveals that binding energies are not much affected by salvation.