Abstract
The three-dimensional reference interaction site model theory was utilized to investigate cucurbituril–guest binding and its corresponding solvation structure. In this study, glycine, tryptophan, phenylalanine and their derivatives were employed as representatives of guest molecules. In the case of aromatic amino acids, phenylalanine shows the most significant binding affinity in cucurbit-7-uril, whereas tryptophan provides the highest binding affinity in cucurbit-8-uril. Although these guest molecules are very similar in molecular volumes, their chemical and physical properties are different. These findings agree well with reports from previous studies. We also found that the substitution of the tert-butyl (–C(CH₃)₃) group at the para-position in phenylalanine provides the highest binding affinity gain among all derivatives. Moreover, the unbound state of glycine is pointed out.