Prediction of the Chromatographic Retention (Lipophilicity) of Some New Methyl‐Thiazole‐Oxadiazoline Derivatives by Multivariate Regression Methods

Abstract

Retention indices for a new series of methyl‐thiazole‐oxadiazolines were determined by reversed phase high performance thin layer chromatography on C₁₈ plates with methanol‐water in different volume proportions as mobile phase. Comparisons based on the multiple regression methods including multiple linear regression (MLR), principal component regression (PCR) and partial least squares (PLS) have been applied to the modelling of chromatographic lipophilicity (R_Mo and b values) by means of 16 different descriptors obtained by using Alchemy package software. The results achieved concerning the prediction of retention indices are highly significant and are in very good agreement with the molecular structure of the compounds investigated. The largest positive charge over the atoms in a molecule (Q₊), the sum of absolute values of the charges on each atom of the molecule (SQ), and the sum of absolute values of the charges on the nitrogens and oxygens in the molecule (SQ_NO) seem to be dominant in the retention mechanism.

Keywords:

• Methyl‐thiazole‐oxadiazolines
• Lipophilicity
• TLC
• QSRR
• MLR
• PCA
• PCR
• PLS