摘要:
Four cholate-based pyridinium compounds were synthesized and their binding abilities toward unmodified amino acids were investigated by UV spectroscopy and fluorescence emission spectroscopy. Studies revealed that the recognition process involved hydrogen bonding, electrostatic force, and pi-pi interaction. The receptor 4a was found to recognize L-tryptophan specifically, and the complex was studied by H-1 NMR spectroscopy. The receptors 4b and 4c showed very little recognition ability toward L-tryptophan, indicating the important role of the benzyl group at pyridinium ring. (C) 2014 Elsevier Ltd. All rights reserved.