手性有机酸薄层色谱保留指数的拓扑模型

基于Kier的分子连接性指数及邻接矩阵提出新型分子连接性指数（^mG_t^v）；引入手性指数（w_j）并建立了手性连接性指数（^mG_t^v）：^mG_t^v=^mG_t^v×w_j。^mG_t^v适用于手性分子、非手性分子及内消旋异构体的结构差异表征。用多元统计回归研究18种手性羟酸和氨基酸的薄层色谱保留指数（R_M）与^mG_t^v的定量构效关系，经最佳变量子集回归建立其四元数学模型，传统的判定系数（R²）为0.973，逐一剔除法（leave-one-out，LOO）的交互验证系数（Q²）为0.950，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个手性连接性指数（⁰C_p^v、²C_p^v、C_ch^v、⁵C_p^v）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和分子的手性特征以及柔韧性、折叠程度等三维结构因素。从上可见，新建手性连接性指数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了一种有效方法。

Topological models of retention index of thin-layer chromatogram for chiral organic acids

On the basis of Kier''s molecular connectivity indices and conjugated matrix, novel molecular connectivity indices (^mG_t^v) were defined and calculated for 18 chiral hydroxyl acids and amino acids. The chiral connectivity indices (^mC_t^v) were introduced by extending ^mG_t^v: ^mC_t^v=^mG_t^v×w_j, where w_j is the chiral index. The quantitative structure-retention index relationship (QSRR) between the retention index (R_M) of thin-layer chromatogram for the chiral organic acids and ^mC_t^v was studied by multivariate statistical regression. By leaps-and-bounds regression analysis, the best four-parameter QSRR model was set up, and the traditional correlation coefficient (R²) and the cross-validation correlation coefficient (Q²) of leave-one-out (LOO) were 0.973 and 0.950, respectively. The results demonstrated that the model was highly reliable and had good predictive ability from the point of view of statistics. From the four parameters (⁰C_p^v, ²C_p^v, C_ch^v, ⁵C_p^v) of the model, it is known that the dominant influence factors of the retention index were the molecular structure characteristics of two-dimensional and the space factors: the chiral characteristics, the flexibility and the puckered degree of molecules for the chiral organic acids. The results showed that the new parameter ^mC_t^v had good rationality and efficiency for the retention indices of the chiral organic acids. Therefore, an effective method was provided to predict the retention indices of the chiral organic acids.