Promotion of radiation-induced formation of 8-oxo-7,8-dihydro-2′-deoxyguanosine by nitro 5-Deazaflavin derivatives

6-Nitro- and 8-nitro-5-deazaflavin derivatives have been found to enhance prominently the radiation-induced formation of 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodGuo) at the expense of formation of 2,6-diamino-4-hydroxy-5-formamidopyrimidine nucleosides (FapydGuo) both in deaerated and in N2O saturated aqueous 2′-deoxyguanosine solutions. The radiosensitizing capacity of a 9-nitro-5-deazflavin derivative was observed only in the N2O saturated aqueous solutions.