Formation of a mutagen, glyoxal, from DNA treated with oxygen free radicals

Oxygen free radicals cause extensive chemical changes in DNA, including base and sugar modifications and strand breaks. In the present study we found that a mutagen, glyoxal, is produced by exposure of DNA to an oxygen radical forming system (5 mM FeSO4-EDTA, 37 degrees C, 60 min). It was produced with 17 times higher efficiency than 8-hydroxydeoxyguanosine. Thus it is possible that the formation of glyoxal is one of the major types of damage in DNA exposed to oxygen free radicals.