QSRR approach in examining selected azo dyes

ABSTRACT

Azo dyes as the most numerous and widely applied class of synthetic dyes in various industries at the same time represent the great polluter of the aquatic systems and environment. Most of them are hydrophobic and resistant to degradation, but also they express diverse biological activity. The preliminary examinations of the bioactivity of the compounds include the estimation of their lipophilicity. The lipophilicity, as the key molecular descriptor for assuming an activity in a biological system for group of thiouracil azo dyes, was determined by the reversed-phase thin-layer chromatography (RPTLC_18F254s) in different mixtures of water and (ethanol, i-propanol, dioxane, tetrahydrofurane) and mathematically using relevant software packages. The insight into the relationship between the chromatographic retention parameters, and m of azo dyes with the partition coefficient log P, was attained by applying the linear regression analysis, Cluster analysis, and principal component analysis. All the applied methods have resulted in good agreements of the studied lipophilicity parameters of azo dyes. Also, these methods provided significant informations about the influence of the organic modifier on one side as well as the impact of the polarity and the electronic effect of substituent of examined dyes on their lipophilicity.

GRAPHICAL ABSTRACT

KEYWORDS:

• Chromatographic retention parameters
• Hammett substituent constant
• log P
• multivariate methods
• thiouracil azo dyes