Free Radicals of Nucleic-Acid Components Induced by Radiation from Atomic Reactor

Nucleic-acid bases and pyrimidine nucleosides have been irradiated at room temperature as dry powders in pneumatic tube of atomic reactor. Total dose is estimated as 1.8×107 rad. ESR measurement has been made at 77°K and the first derivative spectra obtained are similar to those already reported on the experiment with γ-irradiation with one exception for adenine. Radical yields of the bases correspond to the order: cytosine>adenine>uracil>thymine>guanine. In the case of pyrimidine nucleosides, cytidine>uridine>thymidine. The radical yields of the nucleosides are about ten times higher than the bases.