Theoretical Characterization of the Reduction Potentials of Nucleic Acids in Solution

Here, we present the theoretical-computational modeling of the oxidation properties of four DNA nucleosides and nucleotides and a set of dinucleotides in solutions. Our estimates of the vertical ionization energies and reduction potentials, close to the corresponding experimental data, show that an accurate calculation of the molecular electronic properties in solutions requires a proper treatment of the effect of the environment. In particular, we found that the effect of the environment is to stabilize the oxidized state of the nucleobases resulting in a remarkable reduction-up to 6.6 eV-of the energy with respect to the gas phase. Our estimates of the aqueous and gas-phase vertical ionization energies, in good agreement with photoelectron spectroscopy experiments, also show that the effect on the reduction potential of the phosphate group and of the additional nucleotide in dinucleotides is rather limited.

Automated summary

Theoretical-computational modeling of oxidation properties of DNA nucleosides and nucleotides in solutions shows that accurate calculation of molecular electronic properties requires considering the effect of the environment. The environment stabilizes the oxidized state of nucleobases in solutions, leading to a significant reduction in energy compared to the gas phase. Additionally, the impact of the phosphate group and additional nucleotide on the reduction potential of dinucleotides is limited.