Manchester Interdisciplinary Biocentre (MIB), 131 Princess Street, Manchester M17DN, Great Britain.
J Chem Inf Model. 2010 Jan;50(1):87-96. doi: 10.1021/ci900396k.
The basicities of 125 pyridine derivatives in the gas phase and in water have been correlated with the electron density properties within the framework of quantum topological molecular similarity (QTMS). We used the theory of quantum chemical topology (QCT) to provide ab initio descriptors that are able to predict pK(b) values. Partial least squares (PLS) and the machine-learning technique Kriging generated validated models. Properties were considered for systems in their neutral and protonated forms. The compounds were divided into a training set, used to develop the models, and a test set, for which the predicted values of the different models were compared with the experimental ones. The results were found to be good for those compounds with substituents in the meta and para positions, whereas the use of Kriging was required to obtain reasonable results when ortho derivatives were included. The basicity was found to be better described in the gas phase than in water. Special attention was paid to external validation.
已将气相和水中 125 种吡啶衍生物的碱度与量子拓扑分子相似性（QTMS）框架内的电子密度性质相关联。我们使用量子化学拓扑学（QCT）理论提供了能够预测 pK（b）值的从头算描述符。偏最小二乘（PLS）和机器学习技术克里金生成了经过验证的模型。中性和质子化形式的系统都考虑了这些性质。将化合物分为训练集和测试集，用于开发模型，将不同模型的预测值与实验值进行比较。对于在间位和对位有取代基的化合物，结果发现很好，而当包括邻位衍生物时，则需要使用克里金来获得合理的结果。发现气相中的碱度比在水中描述得更好。特别注意外部验证。
