Molecular Modeling Study of Interactions in the Supramolecular System Dihydroquercetin–β-Cyclodextrin

In this work, the potential use of native β-cyclodextrin (β-CD) as an encapsulating agent for dihydroquercetin (DHQ) was evaluated. Based on the experimental results, which showed the 1:1 inclusion stoichiometry, a computational study of the inclusion of dihydroquercetin in β-cyclodextrin was carried out. Several quantum chemical parameters were calculated, including HOMO and LUMO energies, and HOMO–LUMO gap. The characteristic energy values of the most stable structures of DHQ/β-CD complexes were calculated by the PM7 and B3LYP/6-31G(d,p) methods. The objective was to elucidate the electronic structure, forces, and energetic changes that accompany the complexation process. The complexation energies and chemical reactivity of molecular systems were studied. Additionally, Monte Carlo simulations were performed for a better understanding of the inclusion process. The results showed that the inclusion process is exothermic, and a good correlation was found between the complexation energy and HOMO and LUMO energies.