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Density functional study of protonation of deoxynucleosides: Electrophilic active sites and proton affinities
Author(s) -
Xia Fei,
Xie Hujun,
Cao Zexing
Publication year - 2007
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.21389
Subject(s) - tautomer , deoxyribonucleosides , protonation , affinities , chemistry , electrophile , proton affinity , computational chemistry , proton , density functional theory , stereochemistry , organic chemistry , catalysis , ion , physics , quantum mechanics , enzyme
Possible low‐energy tautomers and their interconversions, electrophilic active sites, and proton affinities of deoxyribonucleosides have been studied by the density functional theory. The calculated results indicate that the protonation features of deoxyribonucleosides are less changed as compared with their corresponding bases. Proton affinities of 2′‐deoxyriboguanosine (dG), 2′‐deoxyribocytidine (dC), 2′‐deoxyriboadenosine (dA), and 2′‐deoxyribothymidine (dT) at the most favored sites are 240.6 kcal mol −1 (N7), 238.5 kcal mol −1 (N3), 233.4 kcal mol −1 (N1), and 217.9 kcal mol −1 (O4), respectively. Predicted tautomerization barriers are substantially high and exclude the coexistence possibility of their low‐energy tautomers at room temperatures. Calculations show good agreement with experiments and provide a basis for description of structures and energetics of neutral and protonated deoxyribonucleosides. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2008