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 N(2)O saturated aqueous 2'-deoxyguanosine solutions. The radiosensitizing capacity of a 9-nitro-5-deazflavin derivative was observed only in the N(2)O saturated aqueous solutions.