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Internet Electronic Journal of Molecular Design - IEJMD, ISSN 1538-6414, CODEN IEJMAT
| ABSTRACT - Internet Electron. J. Mol. Des. December 2004, Volume 3, Number 12, 789-801 |
Theoretical study of interaction between adenine and M+ (M = Li,
Na, K, Rb, Cs) and M2+ (M = Mg, Ca, Sr, Ba)
Majid Monajjemi, Sepideh Ketabi, Reza Ghiasi, Karim Zare, Hoda Passdar, Mehrnosh Karimkhani, and Lyla Saedi
Internet Electron. J. Mol. Des. 2004, 3, 789-801
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Abstract:
The interaction of alkali and alkaline earth metals with adenine is an
interesting target of studies in connection with bioinorganic
chemistry and biological chemistry of toxicity and carcinogenicity.
We studied interactions of one of the N7 of adenine and its tautomer
with alkali metals (Li+, Na+,
K+, Rb+ and Cs+) and alkaline earth
metals (Mg2+, Ca2+, Sr2+
and Ba2+) by ab initio calculations. The
stability of these species has been studied in gas phase. The
characterization of C8-N9, C8-N7, N7-C5, N4-C3 and N9-C4 bonds
has been made with the NBO method and the interactions that cause
the strongest stabilization have been studied, as well. The stability of
metalated adenine and its tautomer has been studied
thermochemically. The present study reports the quantum chemistry
analysis of the metal-assisted tautomerization. We have used ab initio
and DFT methods at the HF and B3LYP levels of theory. The
interactions of alkali and alkaline earth metals with N7 of adenine
and its tautomer stabilize rare tautomer respect to major form.
Thermochemical analysis shows that the stability of metalated
adenine is more for less electropositive metals. These results show
that the basicity of metalated adenine has been increased. NBO
calculations show that in metalated adenine N1 is less basic.
Metalation of N7 of adenine and its tautomer by alkali and earth
alkali metals cause to stabilize the rare tautomers. Metalation affects
some bonding and structural properties, such as bond distances and
atomic charges.
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