Chiral Selective Transmembrane Transport of Amino Acids through Artificial Channels

Peptide-appended pillar[n]arene (n = 5, 6) derivatives have been synthesized. H-1 NMR and IR studies revealed that the molecules adopt a tubular conformation in solution and lipid bilayer membranes. Kinetic measurements using the fluorescent labeling method with lipid vesicles revealed that these molecules can efficiently mediate the transport of amino acids across lipid membranes at a very low channel-to-lipid ratio (EC50 = 0.002 mol %). In several cases, chiral selectivity for amino acid enantiomers was achieved, which is one of the key functions of natural amino acid channels.