Department of Computer-Aided Molecular Design, Institute of Physiologically Active Compounds of the Russian Academy of Sciences, Chernogolovka, Moscow region, Russia.
SAR QSAR Environ Res. 2009 Jul;20(5-6):501-18. doi: 10.1080/10629360903278701.
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.
基于 HYBOT 程序计算的物理化学描述符，获得了化学水合热力学（吉布斯自由能变化、DeltaG(air/water)、焓、DeltaH(air/water)和熵 DeltaS(air/water)）的稳定且可预测的定量结构-性质关系（QSPR）模型。该模型的训练集（n = 151）和测试集（n = 37）结构多样，包括 13 种单官能化学类。所应用的 HYBOT 描述符包括分子极化率 alpha（作为体积相关项）、分子中所有原子的部分负电荷之和 SigmaQ(-)（作为静电项）以及氢键供体和受体因子 SigmaC(a)和 SigmaC(d)（作为氢键项）。对于吉布斯自由能和焓的变化，最终方程提供了良好的统计标准和实验测定误差水平的标准偏差。上述四个术语都对水合焓有重要贡献，每个术语都增加了焓的负值。水合吉布斯自由能主要取决于溶质和水分子之间的氢键。位阻和静电项的作用方向相反，部分相互补偿。熵的变化与氢键接受能力的增加相关，而其他三个描述符则呈相反的相关性。
