The reaction of hydrogen atoms with thymine and DNA.

Abstract

Results confirm that the thymyl radical is indeed formed by the addition of a hydrogen atom to carbon (6) of thymine, and that its formation does not require UV or high-energy radiation. The 2 methylene protons in this radical appear to be inequivalent. Radicals (unidentified as yet) are also formed in DNA subjected to hydrogen atom bombardment. Inasmuch as hydrogen atoms appear to be important intermediates in the photo- and radiation damage of biological compounds, the present technique of hydrogen atom bombardment may help to elucidate secondary reactions involved in such damage.