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- Bondesson, Laban, et al.
(författare)
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A linear scaling study of solvent-solute interaction energy of drug molecules in aqua solution
- 2007
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Ingår i: Journal of Physical Chemistry B. - : American Chemical Society (ACS). - 1520-6106 .- 1520-5207. ; 111:34, s. 10320-10328
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Tidskriftsartikel (refereegranskat)abstract
- Solvent-solute interaction energies for three well-known drug molecules in water solution are computed at the Hartree-Fock and B3LYP density functional theory levels using a linear scaling technique, which allows one to explicitly include in the model water molecules up to 14 A away from the solute molecule. The dependence of calculated interaction energies on the amount of included solvent has been examined. It is found that it is necessary to account for water molecules within an 8 A radius around the drug molecule to reach the saturated solvent interaction level. Effects of electron correlation and basis set on solvent-solute interaction energies are discussed.
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- Bondesson, Laban, et al.
(författare)
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Basis set dependence of solute-solvent interaction energy of benzene in water : a HF/DFT study
- 2008
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Ingår i: Journal of Computational Chemistry. - : Wiley. - 0192-8651 .- 1096-987X. ; 29:11, s. 1725-1732
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Tidskriftsartikel (refereegranskat)abstract
- Solute-solvent interaction energies for the benzene molecule dissolved in water are computed using Hartree-Fock and B3LYP density functional theories. Explicit solvent molecules up to 14-angstrom away from the dissolved benzene molecule are included in the calculation of interaction energies. Both basis set dependence and basis Set Superposition errors are carefully examined. It is found that the use of a larger basis set for the region near the solute together with a smaller basis set for the outer region gives results very close to what would have been obtained if the larger basis set had been used for the whole system. It is also shown that a correction for the basis Set superposition error is a necessary component in this kind of calculations. With this correction, results obtained with different tested basis sets converge to within 1 kcal/mol.
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7. |
- Bondesson, Laban, et al.
(författare)
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Density functional theory calculations of hydrogen bonding energies of drug molecules
- 2006
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Ingår i: Journal of Molecular Structure. - : Elsevier BV. - 0022-2860 .- 1872-8014 .- 0166-1280. ; 776:1-3, s. 61-68
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Tidskriftsartikel (refereegranskat)abstract
- Hydrogen bonding energies of several drug molecules have been calculated using hybrid density functional theory with inclusion of basis set superposition error corrections. The calculated total hydrogen bonding energy of each drug molecule has been compared with the result of a conceptually simple additive model, from which the summation of hydrogen bonding energies of individual polar groups present in the drug molecule are considered. It is shown that the validity of the additive model is strongly conditional, and to some extent predictable: In cases where the hydrogen bonding group is isolated the addition model can be of relevance, while in cases where the hydrogen bonding groups are interconnected through pi-conjugation rings or chains of the drug molecules it introduces substantial errors. It is suggested that such strong cooperative effects of hydrogen bonds should always be taken into account for evaluation of the hydrogen bonding energies of drug molecules.
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9. |
- Bondesson, Laban, et al.
(författare)
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Hydrogen bonding effects on infrared and Raman spectra of drug molecules
- 2007
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Ingår i: Spectrochimica Acta Part A - Molecular and Biomolecular Spectroscopy. - : Elsevier BV. - 1386-1425 .- 1873-3557. ; 66:2, s. 213-224
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Tidskriftsartikel (refereegranskat)abstract
- Infrared and Raman spectra of three drug molecules, aspirin, caffeine and ibuprofen, in gas phase and in aqueous solution have been simulated using hybrid density functional theory. The long range solvent effect is modelled by the polarizable continuum model, while the short range hydrogen bonding effects are taken care of by the super-molecular approach with explicit inclusion of water molecules. The calculated spectra are found to compare well with available experimental results. The agreement obtained make grounds for proposing theoretical modeling as a tool for characterizing changes in the bonding environments of drug molecules in terms of particular variations in their IR and Raman spectra.
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