Host-Guest Interactions of Cucurbit[7]uril and 2-(2-phenylethyl)chromone in Aqueous Solutions

In this study, the effect of interactions between 2-(2-phenylethyl)chromone (PCM) and cucurbit[7]uril (Q[7]) was determined via UV-vis spectroscopy, mass spectrometry, and nuclear magnetic resonance spectroscopy. The results demonstrated that PCM and Q[7] were able to formed a 1 : 1 host–guest inclusion complex (PCM@Q[7]) with a binding constant of 2.9×108 L/mol. These interactions significantly increased the aqueous solubility of PCM by 2.4 fold, leading to an extended release duration of PCM in both artificial gastric and intestinal juices. However, the stability of PCM in artificial gastroenteric juices remained unaffected.