Deoxyribonucleic acid, DNA, is very important molecule in biological systems and is comparatively stable chemical substance. DNA made by four nucleobases adenine (A), thymine (T) or, guanine (G), and cytosine (C) which are used by nature for storing the information of life. It is well known that the coupling of base pairs can affected by free radical intermediates which are produced in living systems under normal conditions. On the other hand chemical species such as phenyl and phenoxy radicals can be generated by ionizing radiation, which can damage macromolecules, including DNA, proteins and lipids. In the case of DNA, any change in structure can be treated as a mutation and some phenolic compounds have been shown to be cytotoxic and/or genotoxic in a variety of biological systems. Although, the phenoxy and phenyl radicals are very common materials in the environment, the role of these species in DNA damage process has not been investigated.
