Partition coefficients of amino acids and hydrophobic parameters π of their side-chains as measured by thin-layer chromatography

Abstract

Partition coefficients in n-octanol—water have been determined for the naturally occurring and some synthetic α-amino acids using thin-layer chromatography in different solvent systems. Both literature and newly measured values of partition coefficients in n-octanol—water have been used as reference values. The relationship between R F values and partition coefficients ( P) has been established. Hansch hydrophobic parameters π have been evaluated for the side-chains. Fragmental group contributions to the overall π-value have also been evaluated. In this way P and π values of any non-listed amino acid become easily accessible either by thin-layer chromatography or by computation.