Changes of fluorescence spectra of 2'-deoxyadenosine in aqueous solution by radiation

Aqueous solution of 2'-deoxyadenosine (5 X 10(-4) M, buffered at pH 7.0) was irradiated with 60Co gamma-rays under N2, O2, N2O and t-BuOH-N2 atmospheres in order to compare with adenine radiolysis previously reported. By exposure to radiation, the fluorescence was found to increase more markedly than that from adenine under all conditions of radiolysis. This result indicates that not only base moiety but also sugar moiety participate in the formation of highly fluorescent products. In this 2'-deoxyadenosine radiolysis, both OH and e-aq take part in the formation of such products, but OH predominates over over e-aq when both active species are present, as observed in adenine radiolysis.