| Cite this article as: Wang Shu-Dong,Gong WeiPing,Wang Ye,Sun Tao,Wu Jing-Jie. Theoretical Study on the Stable Conformation of 5R, 6S-Tg Stereoisomers [J]. J. At. Mol. Phys.(原子与分子物理学报), 2025, 42: 046008 (in Chinese) |
| Theoretical Study on the Stable Conformation of 5R, 6S-Tg Stereoisomers |
| Hits 227 Download times 262 Received:November 25, 2023 Revised:December 21, 2023 |
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| DOI
10.19855/j.1000-0364.2025.046008 |
| Key Words
Thymine Glycol DFT Hydrogen bond Stereoisomer |
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| Abstract
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| Thymine glycol (Tg) is the most common DNA oxidative damage, and there are thousands of Tg damages in human genome. Tg has a strong blocking effect on DNA polymerase and may lead to serious consequences such as cell death and cancer. Once Tg is generated, it exists in the form of a mixture of two cis-trans stereoisomers, and the repair enzyme exhibits stereoselectivity for Tg repair. Among all isomers, 5R,6S-Tg with the highest quantity. NMR study have shown that the 5-CH3of 5R,6S-Tg may have two different conformations, axial or equatorial, however, the most stable conformation of 5R,6S-Tg is still debated. Studies based on the base level indicate that the 5R,6S-Tg is most stable when the 5-CH3 is axial, however, our calculations at the nucleoside level indicate that the 5R, 6S-Tg with 5-CH3 in equatorial is the most stable conformation, CCSD (T)/6-311++G(d,p) calculation confirms the results. Further analysis showed that the synergistic effect of intramolecular hydrogen bonding and π-π conjugation stabilized the equatorial conformation of 5R,6S-Tg. |
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