Thermodynamics of organic chemical hydration: QSPR models using physicochemical HYBOT descriptors
| Autor: | O. E. Raevskaya, R. Mannhold, Y. V. Liplavskiy, Oleg A. Raevsky |
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| Rok vydání: | 2009 |
| Předmět: |
Quantitative Biology::Biomolecules
Quantitative structure–activity relationship Chemistry Enthalpy Quantitative Structure-Activity Relationship Thermodynamics Hydrogen Bonding Bioengineering General Medicine Acceptor Gibbs free energy Entropy (classical thermodynamics) symbols.namesake Computational chemistry Polarizability Drug Discovery symbols Molecular Medicine Molecule Organic Chemicals Physics::Chemical Physics Chemical hydration Software Hydrogen |
| Zdroj: | SAR and QSAR in Environmental Research. 20:501-518 |
| ISSN: | 1029-046X 1062-936X |
| DOI: | 10.1080/10629360903278701 |
| Popis: | Stable and predictive quantitative structure-property relationship (QSPR) models of thermodynamics of chemical hydration (changes in Gibbs energy, DeltaG(air/water), enthalpy, DeltaH(air/water) and entropy DeltaS(air/water)) were obtained on the basis of physicochemical descriptors calculated by the HYBOT program. The structurally diverse training set (n = 151) and test set (n = 37) included 13 mono-functional chemical classes. The applied HYBOT descriptors comprise molecular polarizability alpha (as a volume-related term), the sum of partial negative charges on all atoms in a molecule SigmaQ(-) (as an electrostatic term) and the sum of H-bond acceptor and donor factors SigmaC(a) and SigmaC(d) (as H-bond terms). Final equations for changes in Gibbs energy and enthalpy provided good statistical criteria and standard deviations on the level of errors of experimental determinations. All four above-mentioned terms essentially contribute to hydration enthalpy and each of them increases negative values of enthalpy. Hydration Gibbs energy predominantly depends on hydrogen bonding between solute and water molecules. Steric and electrostatic terms act in opposite directions and partly compensate each other. Changes in entropy correlate with increasing H-bond acceptor ability, whereas the other three descriptors exhibit inverse correlations. |
| Databáze: | OpenAIRE |
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