Chemometric characterization of (chromatographic) lipophilicity parameters of newly synthesized s‐triazine derivatives

Abstract

A (chromatographic) lipophilicity parameters of newly synthesized 2,4-bis(substituted)-6-chloro-s-triazines were studied. PCA-HCA were performed in order to classify and organize various chromatographic lipophilicity parameters that were determined by using different stationary and mobile phases and by various chromatographic techniques. The PCA-HCA indicates that for the set of investigated compounds, similar lipophilicity scales are given by chromatographic systems with covalently bonded hydrocarbons as a stationary phase and acetonitrile as a mobile phase modifier. Another cluster of lipophilicity scales forms cyano and octadecylsilica stationary phases with dioxane or tetrahydrofuran as a mobile phase modifiers. The general arrangement of investigated compounds along PC1 was according to the increase in lipophilicity forming two clusters (one of lower and the other of higher lipophilicity). PCA study of R M values underline the differences concerning solvent fraction. Also reveal that HPTLC systems on amino plates are distinguishable from the cyano and octadecylsilica supports, which were similar.

Multivariate assessment of lipophilicity scales—computational and reversed phase thin-layer chromatographic indices

“…For this type of problems, correlation matrices are most often used. Pearson's correlation coefficient has been already extensively used for the assessment of novel lipophilicity indices [24,25,44]. In order to extend the capabilities of SRD to this type of problems, we have implemented a MS Excel VBA macro for the generation of "SRD heatmaps", where we use all of the variables in turn as the reference to produce a matrix of SRD values.…”

“…Instead of the current misuse of Pearson's correlation matrices [24,25,44] we would like to encourage the implementation of: (a) adequate arrangement of variables and (b) coloring schemes which enables patterns among variables to be easily perceivable. The choice of the best variable/lipophilicity measure following the aforementioned matrix arrangement is straightforward, i.e.…”

“…Many procedures use similarities among computationally estimated values and experimentally derived lipophilicity indices as a criterion to select the best one. Such similarities are most often obtained from hierarchical clustering (HCA) [43,44], principal component analysis [21,23,25,45], or simple correlations based on parametric statistics such as Pearson's correlation coefficient [24,25,44]. The last one is applicable only if the data is normally distributed, which is often not the case.…”

Correlation between structure, retention and activity of cholic acid derived cis–trans isomeric bis‐steroidal tetraoxanes

“…The advantages of this method are: applicability to compounds with higher lipophilicity (log P ranging from 0 to 7), only a small amount of the sample required, low sensitivity to impurities, rapid determination, good accuracy and excellent reproducibility [4]. The estimation of lipophilicity parameter strongly varies depending on the type of chromatographic system employed, and a few multivariate statistical techniques can be used to select the most appropriate ones [5]. Unlike this method, the traditional shake-flask method [6] faces problems such as poor reproducibility, long time of analysis and it requires a larger amount of pure compounds.…”

Structure–Retention Relationship Study of 2,4-dioxotetrahydro-1,3-thiazole Derivatives

“…For lipophilicity determination, thin-layer chromatography (TLC) has a great efficiency. [9,10] Rapidly increasing use of lipophilicity in modelling of the biological processes indicates the great need for valid procedures for quantification of this physicochemical property.…”