Functionalized calix[4]arenes as transporters of biological compounds

Calix[n]arenes as cyclic oligomers are important receptors of supramolecular hosts involved in
host-guest molecular recognition of various compounds as well as in analytical applications such
as separation of chemical or biochemical compounds. Derivatisation of calix[n]arenes at the
upper and lower rim in order to introduce various functional groups has led to new compounds
with desired properties. In the present contribution, we have reported aspects of complex formation and transport through liquid membrane assisted by the pH gradient of amino acid methylesters by using a
series of calix[4]arenes substituted by acid and amido functions, glycolic chains, and hydroxyl
groups. All these receptors have been used as carriers for transport through liquid membrane of
aromatic amino acid methylesters aiming at their separation. The complexation properties of
calix[n]arenes towards amino acids have been evaluated by UV-Vis spectrometry.
The effects of physicochemical parameters that might influence the separation of amino acids by
transport process through liquid membrane using calix[n]arenes as carriers have been
investigated.