Eureka! Institutional Repository

5',8-Cyclo-2'-deoxypurines (cPu) are tandem-type lesions observed among DNA purine modifications and they are identified in in vitro experiments and in mammalian cellular DNA in vivo. These lesions are produced by the 2'-deoxyadenosine and 2’-deoxyguanosine and they are found in two diastereomeric forms, the 5'R form and the 5'S. They are generated exclusively by hydroxyl radical attack to 2’-deoxyribose units generating the C5’ radical, followed by cyclization with the C8 position of the purine base. This thesis presents indicative sample of the studies on cyclopurines, the possible pathways for their repair, stability studies and the quantitative determination of their levels of lesions in various types of cells. Moreover, the impact of cyclopurines lesions on transcription and genetic instability and, consequently, the way which they affect our body and lead to diseases like cancer and aging is presented. Furthermore, the effect of some antioxidants, which can act preventively against these damages, has been investigated and discusssed. The latter findings may support further studies the on antioxidants protective role against damaging species leading to illnesses and diseases in the development of which cyclopurines play crucial role