作者:Yu-Lin Chen、Dave J. Barlow、Xiao-Le Kong、Yong-Min Ma、Robert C. Hider
DOI:10.1039/c2dt12396g
日期:——
As an aid in optimising the design of 3-hydroxypyridin-4-ones (HPOs) intended for use as therapeutic Fe3+ chelating agents, various quantum mechanical (QM) and semi-empirical (QSAR) methods have been explored for predicting the pKa values of the hydroxyl groups in these compounds. Using a training set of 15 HPOs with known hydroxyl pKa values, reliable predictions are shown to be obtained with QM calculations using the B3LYP/6-31+G(d)/CPCM model chemistry (with Pauling radii, and water as solvent). With this methodology, the observed hydroxyl pKa values for the training set compound are closely matched by the predicted pKa values, with the correlation between the observed and predicted values giving r2 = 0.98. Predictions subsequently made by this method for a test set of 48 HPOs of known hydroxyl pKa values (11 of which were determined experimentally in this study), gave predicted pKa values accurate to within ±0.2 log units. In order to further investigate the predictive power of the method, two novel HPOs were synthesised and their hydroxyl pKa values were determined experimentally. Comparison of these predicted pKa values against the measured values gave absolute deviations of 0.13 (10.18 vs. 10.31) and 0.43 (5.58 vs. 5.15).
作为优化用于治疗性Fe3+螯合剂的3-羟基吡啶-4-酮(HPOs)设计的辅助工具,探索了多种量子力学(QM)和半经验(QSAR)方法,用于预测这些化合物中羟基的pKa值。利用15个已知羟基pKa值的HPO训练集,结果表明,使用B3LYP/6-31+G(d)/CPCM模型化学(采用Pauling半径,并以水作为溶剂)所进行的QM计算可以获得可靠的预测。采用这种方法,训练集中化合物的观察到的羟基pKa值与预测的pKa值紧密匹配,观察值与预测值之间的关联性为r² = 0.98。随后,该方法对48个已知羟基pKa值的HPO测试集(其中11个是在本研究中实验确定的)进行了预测,预测的pKa值在±0.2对数单位内是准确的。为了进一步研究该方法的预测能力,合成了两个新型HPO,并实验确定了它们的羟基pKa值。将这些预测的pKa值与测量值进行比较,得到了绝对偏差分别为0.13(10.18 vs. 10.31)和0.43(5.58 vs. 5.15)。