Thin-layer chromatography on reversed phase in the characterization of retention behaviour, lipophilicity, and pharmacokinetics of cyanoacetamide derivatives

Abstract

Biological activity of a molecule is closely related to its lipophilicity. This significant parameter was determined for a group of potentially bioactive N-(4-phenylmonosubstituted)-2-cyanoacetamides applying thin-layer chromatography on reversed phase (RP-TLC) in mixtures of water and two organic modifiers separately, i-propanol and dioxane. The effect of the chemical structure of derivatives and the influence of the applied organic modifier on their retention were studied. The determined chromatographic retention constants, R-M(0), and the chromatographic parameter, m, of compounds were correlated with software calculated partition coefficients, log P as the standard measure of lipophilicity and with different pharmacokinetic predictors applying classical linear and multiple regression analysis. By classical linear regression analysis in both water-modifier systems only R-M(0)-log P and m-log P correlations were established (average r, 0.909 and 0.826). All studied relationships were enhanced by molecular descriptors that fulfilled the modified Lipinski's rule of five. Thereby, the performed multiple regression analysis gave better correlations (for R-M(0)-log P and m-log P average r(2), 0.994 and 0.993; for R-M(0)-pharmacokinetic parameters and m-pharmacokinetic parameters average r(2) 0.978 and 0.980). The obtained results indicate that the chromatographic parameters, R-M(0) and m determined by RP-TLC at given conditions could be used successfully for the description of lipophilicity and the evaluation of pharmacokinetic properties of N-(4-phenylmonosubstituted)-2-cyanoacetamides as potential bioactive molecules.