Recent aspects of the radiation chemistry of pyrimidine and purine 2'-deoxyribonucleosides in aqueous solutions

Recent data on the radiation chemistry of 2'-deoxyribonucleosides are discussed. Various mechanisms such as dismutation, charge transfer, and dimerization are suggested to explain the formation of 5, 6- dihydrothymidine, its various 5- and/or 6-hydroxylated derivatives, and noncyclobutane-type dimers. Additional information on these complex processes has been obtained using radical scavengers and radio sensitizing agents. (The latter act mainly by electron transfer and binding reactions). These studies have also been extended to purine nucleosides. In particular, specific reactions have been studied for the radiationinduced sugar radicals of 2'-deoxyguanosine.