Modeling of Chromatographic Lipophilicity Indices of Quaternary Ammonium and Nitrone Derivatives and Their Thiazolic Salts Using Molecular Descriptors
Cristina Onişor, Mariana Palage, Costel Sârbu · Analytical Letters · 2010
The goal of this study was to estimate the lipophilicity and to investigate the molecular mechanism of retention and to find an objective manner of quantitative comparison of chemically bonded stationary phases for high performance thin layer chromatography (HPTLC) in terms of their (dis)similarities for 15 carefully designed, structurally diverse quaternary ammonium and nitrone derivatives and their thiazolic salts with distinctly distinguished functional groups. Quantitative structure–retention relationships (QSRR) with descriptors available only in Dragon version 5.4 and ChemDraw Ultra Plus 9.0 were performed. On the other hand, the combination of QSRR and Genetic algorithm (GA) appeared as one of the most efficient tools for searching and identification of the most characteristic descriptors (variables). By comparing the coefficients of the multiple regression models obtained from investigated reversed-phases, the relative effects of different solute properties can be revealed and, thus, the retention mechanism (lipophilicity) of the considered compounds can be understood and predicted. The most statistical significant QSRR models were obtained in the case of CNF254s (R2 = 98.90%) and NH2 F254s (R2 = 96.66%) stationary phase.