β-Cyclodextrin derivative as chiral carrier in membrane transport of some aromatic amino acids

The chiral functionalized β-cyclodextrin (heptakis (2,3,6-tri-o-acetyl)-β-cyclodextrin) was studied as an extraction receptor in liquid–liquid extraction and carrier through bulk liquid membrane for highlighting its ability to enantiomeric discrimination of some native aromatic amino acids (tryptophane, phenylalanine, and tyrosine) and methylester derivatives (tryptophane methylester hydrochloride, phenylalanine methylester hydrochloride, and tyrosine methylester hydrochloride). The receptor exhibited carrier ability for aromatic amino acids transport through chloroform liquid membrane, especially for l-amino acids form aiming at their separation. Active transport of amino acids assisted by the pH gradient was carried out. Additional, the circular dichroism measurements were performed to point out the enantiomeric discrimination of aromatic amino acids by functionalized β-cyclodextrin. The results showed that the structural properties of amino acids are an important parameter in extraction and transport experiments.