Extraction and transport behaviour of aromatic amino acids by modified cyclodextrin

The extraction efficiency together with the active transport assisted by the pH gradient trough liquid membrane of some aromatic native and derivative amino acids by using heptakis (2,3,6-tri-O-acetyl)-B-cyclodextrin as extractant agent or carrier has been studied. The modified cyclodextrin extracted aromatic amino acids, native (L-tryptophane, L-phenylalanine and L-tyrosine) and their methylester derivatives from aqueous phase into the organic phase. Moreover, the modified cyclodextrin exibits the carrier abilities for amino acid methylesters trough liquid membrane. In the case of transport processes involving liquid membranes, the physicochemical properties of the solvents play an important role in membrane stability. The results demonstrated that the inclusion properties of the investigated host are correlated with the structural properties of amino acid, and they also suggest further possibilities for optimal separation of amino acids derivatives.