Theoretical investigations on hydrated 6,8-dithioguanine tautomers

Karthika, M.; Senthilkumar, L.; Kanakaraju, R.

doi:10.1007/s11224-012-9946-9

Cited by 8 publications

(2 citation statements)

References 48 publications

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“…The bond length of H–S is 2.35 Å, in the range of hydrogen bonds for sulfur atoms. 51 Meanwhile, for the structure of the crossing point, the H–S bond is increased to 2.50 Å, and the surface between S and H is just green colored, indicating that the hydrogen bond disappears. Thus, the hydrogen bond interaction stabilizes 6tGua at the initial point of the triplet decay (T 1 optimized structure) but not at the crossing point.…”

Section: Resultsmentioning

confidence: 99%

Unexpected longer T₁ lifetime of 6-sulfur guanine than 6-selenium guanine: the solvent effect of hydrogen bonds to brake the triplet decay

Liu,

Lee,

Chen

et al. 2024

Phys. Chem. Chem. Phys.

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Section: Resultsmentioning

confidence: 99%

Unexpected longer T₁ lifetime of 6-sulfur guanine than 6-selenium guanine: the solvent effect of hydrogen bonds to brake the triplet decay

Liu,

Lee,

Chen

et al. 2024

Phys. Chem. Chem. Phys.

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“…The higher dipole moment of ketoprofen results from the presence of an additional oxygen atom, which is an acceptor of hydrogen bonds. The earlier studies also show that the dipole moment would be enhanced during the formation of hydrogen bonds [49].…”

Section: Lipophilicity and Dipole Momentsmentioning

confidence: 86%

Comparative Theoretical Study of Stability, Lypophilicity, Dipole Moments, Acidity and Spectroscopic Properties of Non-Steroidal Anti-Inflammatory Drugs: Ibuprofen, Ketoprofen and Flurbiprofen

Benjamine

Jacques

Koné

et al. 2020

CSIJ

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A comparative theoretical study of some physicochemical properties of R and S enantiomers of ibuprofen, ketoprofen and flurbiprofen is undertaken in order to understand their reactivity. To do this, DFT and TD-DFT methods at the B3LYP/6-311G(d,p) level theory are used. The partition coefficient determined is 3.72 for ibuprofen, 2.81 for ketoprofen and 4.12. for flurbiprofen. That means that these NSAIDs are characterized by a high lipophilicity. The calculated Gibbs energies show that the R enantiomer is the most stable in the case of ibuprofen and the S enantiomer in the case of ketoprofen and flurbiprofen. The study of acidity shows that S enantiomer of ibuprofen and R enantiomers of ketoprofen and flurbiprofen are the most acidic enantiomers. TD-DFT calculations show that, the absorption maxima (λmax) of ibuprofen and flurbiprofen correspond to the HOMO→LUMO transition. For ketoprofen, these are associated with the transition HOMO→LUMO+1. These results elucidate the reactivity of the investigated NSAIDs and could help to establish a classification their efficacy.

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Spectroscopic investigations and hydrogen bond interactions of 8-aza analogues of xanthine, theophylline and caffeine: a theoretical study

Karthika¹,

Kanakaraju²,

Lakshmipathi

2013

J Mol Model

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The structure, spectral properties and the hydrogen bond interactions of 8-aza analogues of xanthine, theophylline and caffeine have been studied by using quantum chemical methods. The time-dependent density functional theory (TD-DFT) and the singly excited configuration interaction (CIS) methods are employed to optimize the excited state geometries of isolated 8-azaxanthine, 8-azatheophylline tautomers and 8-azacaffeine in both the gas and solvent phases. The solvent phase calculations are performed using the polarizable continuum model (PCM). The absorption and emission spectra are calculated using the time-dependent density functional theory (TD-DFT) method. The results from the TD-DFT calculations reveal that the excitation spectra are red shifted relative to absorption in aqueous medium. These changes in the transition energies are qualitatively comparable to the experimental data. The examination of molecular orbital reveals that the molecules with a small H→L energy gap possess maximum absorption and emission wavelength. The relative stability and hydrogen bonded interactions of mono and heptahydrated 8-azaxanthine, 8-azatheophylline tautomers and 8-azacaffeine have been studied using the density functional theory (DFT) and Møller Plesset perturbation theory (MP2) implementing the 6-311++G(d,p) basis set. The formation of strong N-H...O bond has resulted in the highest interaction energy among the monohydrates. Hydration does not show any significant impact on the stability of heptahydrated complexes. The atoms in molecule (AIM) and natural bonding orbital (NBO) analyses have been performed to elucidate the nature of the hydrogen bond interactions in these complexes.

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Theoretical investigations on hydrated 6,8-dithioguanine tautomers

Cited by 8 publications

References 48 publications

Unexpected longer T₁ lifetime of 6-sulfur guanine than 6-selenium guanine: the solvent effect of hydrogen bonds to brake the triplet decay

Unexpected longer T₁ lifetime of 6-sulfur guanine than 6-selenium guanine: the solvent effect of hydrogen bonds to brake the triplet decay

Comparative Theoretical Study of Stability, Lypophilicity, Dipole Moments, Acidity and Spectroscopic Properties of Non-Steroidal Anti-Inflammatory Drugs: Ibuprofen, Ketoprofen and Flurbiprofen

Spectroscopic investigations and hydrogen bond interactions of 8-aza analogues of xanthine, theophylline and caffeine: a theoretical study

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Theoretical investigations on hydrated 6,8-dithioguanine tautomers

Cited by 8 publications

References 48 publications

Unexpected longer T1 lifetime of 6-sulfur guanine than 6-selenium guanine: the solvent effect of hydrogen bonds to brake the triplet decay

Unexpected longer T1 lifetime of 6-sulfur guanine than 6-selenium guanine: the solvent effect of hydrogen bonds to brake the triplet decay

Comparative Theoretical Study of Stability, Lypophilicity, Dipole Moments, Acidity and Spectroscopic Properties of Non-Steroidal Anti-Inflammatory Drugs: Ibuprofen, Ketoprofen and Flurbiprofen

Spectroscopic investigations and hydrogen bond interactions of 8-aza analogues of xanthine, theophylline and caffeine: a theoretical study

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Unexpected longer T₁ lifetime of 6-sulfur guanine than 6-selenium guanine: the solvent effect of hydrogen bonds to brake the triplet decay

Unexpected longer T₁ lifetime of 6-sulfur guanine than 6-selenium guanine: the solvent effect of hydrogen bonds to brake the triplet decay