基于手性碳原子的取代基次序规则,提出分子手性指数(wj),结合原子类型电拓扑指数(En)研究18种手性羟基酸和氨基酸的薄层色谱保留指数(RM)的定量关系(QSRR).经最佳变量子集回归建立最佳四元数学模型,传统的相关系数(R2)为0.969,留一法(LOO)的交互验证系数(Q2)为0.943,结果证明具有良好的稳健性及预测能力.根据进入该模型的4个结构参数(wj,E13,E16,E17)可知,影响手性有机酸保留指数的主要因素是分子的二维结构特征(如襒O,—OH,—NH2)和分子的手性特征.综上所述,新建wj及En对手性有机酸的保留指数表征具有合理性与有效性,为预测手性有机酸的保留指数提供一种有效方法.
Based on the order rule for substituents on a chiral carbon atom,a novel structural parameter,the molecular chiral index(wj),was investigated in this paper.A quantitative structure-retention index relationship(QSRR) between the retention index(RM) from a chiral thin-layer chromatogram for 18 chiral organic acids(8 hydroxyl acids and 10 amino acids) and wj,an electrotopological state index for atom types(En) was investigated using multivariate statistical regression.Using leaps-and-bounds regression analysis,an optimal four-parameter QSRR model was set up.The traditional correlation coefficient(R2) and the cross-validation correlation coefficient(Q2) of the leave-one-out(LOO) method were 0.969 and 0.943,respectively.Results demonstrate that the model is highly reliable and that statistically it has a good predictive ability.From the four parameters(wj,E13,E16,E17) of the model,the two-dimensional molecular structure characteristics(such as O,—OH,—NH2) and the chiral characteristics are shown to be decisive factors that affect the retention index for the chiral organic acids.Results also show that the new parameters wj and En are rational and efficient in the determination of retention indices of chiral organic acids.Therefore,this paper provides an effective method to predict the retention indices of chiral organic acids.