Structural behavior of sugar radicals formed by proton transfer reaction of deoxycytidine cation radical: detailed view from NBO analysis

摘要: The cation radicals of DNA constituents generated by the ionizing radiation initiate alteration bases, which is one main type cytotoxic lesions. These radical spices are known for their role in producing nucleic acid strand break, and it important to identify formation at particular atomic site these molecules so that major pathway damage may be trapped. In present study, we explored theoretically energetic, structural, electronic properties possible formed via proton atom abstraction various sites sugar part deoxycytidine employing density functional theory B3LYP/6-311++G (d,p) level. computation revealed 0.0–22.6 kcal/mol energy disparity radicals. Radical-centered carbon increases extent bonding with its adjacent atoms. This tendency should predicting reactivity sugar-based Based on DFT calculations, have following stability order: raH1′ > raH2′ raH4′ raH3′ raH5′ raO5′H raO3′H. Furthermore, influence acidities multiple nucleosides was investigated. For instance upon formation, ΔHacidity O3′H O5′H varies from 348.6 351.5 228.8 227.5 kcal/mol, respectively.