Charge‐transfer chromatographic study on the interaction of amino acids with ethoxylated stearic acid surfactants

Abstract

The interaction of amino acids with ethoxylated stearic acid nonionic surfactants was studied by charge-transfer reversed-phase thin-layer chromatography and the relative strength of interaction was calculated. In the majority of cases the surfactant has a negligible effect on the hydrophobicity of amino acids. Only the binding of Asn, Cys, Gln, Leu, Lys, Met, Nle, Phe, Ser, Trp and Tyr to the surfactants was observed, however, the strength of interaction was fairly low. Stepwise regression analysis proved that the electronic parameters of the amino acids have the highest impact on the strength of interaction. This finding supports the hypothesis that the binding of ethoxylated stearic acid nonionic surfactants to proteins involves more than one amino acid residues and that the hydrophilic forces have a considerable impact on the interaction.

Alkyl Ethoxylated and Alkylphenol Ethoxylated Nonionic Surfactants: Interaction with Bioactive Compounds and Biological Effects

“…A similar study dealing with the interaction of amino acids with ethoxylated stearic acid surfactants found that surfactants interact with free amino acids in the following order: Cys>Phe>Tyr>Asn>Met>Nle>Leu> Gln>Lys>Ser>Trp. In this case the electronic parameters of surfactants had a significant impact on the strength of interaction (31). The forces involved in the binding of nonionic surfactants to proteins are being characterized.…”

Citral stabilization and characterization of nanoemulsions stabilized by a mixture of gelatin and Tween 20 in an acidic system

“…Alkyl ethoxylated non‐ionic surfactants can readily bind to various proteins. Additionally, the hydrophobic moieties of surfactants can bind to apolar amino acids, whereas the hydrophilic ethylene oxide chains can interact with peptide bonds and one or more polar amino acid residues, probably via electrostatic forces and hydrogen bonding . It is favorable that the process of micelle formation bound to gelatin polypeptide chains is induced at concentrations lower than the critical concentration of micelle formation (CMC).…”

Surfactant Modified/Mediated Thin-Layer Chromatographic Systems for the Analysis of Amino Acids

“…This can be concluded from the study that the hydrophobicity of amino acid side chains significantly influenced the strength of interaction. Cserhati [42] also studied the interaction of amino acids with nonionic surfactant (ethoxylated stearic acid) by charge transfer reversed phase thin-layer chromatography. From the study it was observed that only Asn (asparagine), Cys (cysteine), Glu (glutamic acid), Leu (leucine), Lys (lysine), Met (methionine), Nle (norleucine), Phe (phenylalanine), Trp (tryptophan), and Tyr (tyrosine) bind with the surfactant.…”