The interaction between beta-ionone and 2-hydroxypropyl-beta-cyclodextrin during the formation of the inclusion complex

As an aroma material, beta-ionone also has a range of pharmacological activities. To solve its problems such as low bioavailability, water-immiscibility, thermo-instability, and volatility, beta-ionone was successfully encapsulated in 2-hydroxypropyl-beta-cyclodextrin (HP-beta-CD) in our previous work. However, the structure of the product, the interaction between beta-ionone and HP-beta-CD, and the mechanism of action were not clear. In this paper, in order to gain a more profound understanding of the structure and chemical behavior of beta-ionone-HP-beta-CD inclusion complex, the interaction between beta-ionone and HP-beta-CD was investigated by molecular simulation. The optimized structures, binding energy, deformation energy, charge transfer, frontier orbital energy gap, chemical hardness, chemical potential, and electrophilicity index were obtained. In the complex, beta-ionone denotes electrons to HP-beta-CD and carries a positive charge. The negative chemical potential of inclusion complex indicates that complex process is spontaneous. The complex shows a relatively higher reactivity and electrophilicity than beta-ionone and HP-beta-CD.