Quantitative structure-retention relationship and 3D molecular modeling studies of the unusual chromatographic behavior of triphenylmethane derivatives in RPTLC systems

Abstract

Dual retention behavior is observed for triphenylmethane (TPM) derivatives in RPTLC on silica gel plates when the composition of acetone-water mobile phases is varied. The physicochemical and molecular properties of the TPM derivatives causing this unusual retention behavior have been investigated by traditional quantitative structure-retention relationship (QSRR) modeling and by 3D molecular modeling. The QSRR studies were performed by using PLS regression analysis based upon use of selected sets of Dragon molecular descriptors and pharmacokinetically relevant VolSurf descriptors to identify the physicochemical properties that govern chromatographic behavior. Comparative molecular similarity indices analysis (CoMSIA) was used to create the 3D isoenergy contours of favored and unfavored contributions of the molecular fields around the molecules in the RPTLC systems used. The dual retention behavior of the TPM derivatives can be attributed to the propensity of these molecules to become oriented with differ...