Study of Tetrahydrofuran DNA damage by low energy electron radiation using Geant4-DNA toolkit and DFT calculations

Low-energy reactions in hydrated molecular complexes are important in radiobiological processes including radiation therapy. The present study investigates the effect of secondary electrons (70 eV) produced by gamma radiation on tetrahydrofuran molecules in the aqueous medium in the DNA backbone using the Geant4-DNA toolkit and DFT calculations. By using Geant4-DNA, possible deposited energies derived from the primary beam on the target molecule were studied. DFT calculations allowed calculating the appearance energies of possible cations formed by electron-molecule collisions. We found that these amounts of deposited energies are enough to facilitate the ring–break reaction in tetrahydrofuran and finally dissociation of the molecule. These results demonstrate that hydrogen-bonded molecules can affect the stability of the molecule.