Insight into the inclusion mechanisms of curcumin in β-cyclodextrin using a screening strategy: Molecular simulation and experimental study

Materials Studio 2018 software was used to model β -cyclodextrin ( β -CD) and 16 flavonoids, and Auto Dock 4.0 was used for molecular docking. From the molecular dynamics simulations, curcumin (CUR) was identified as the most suitable inclusion in β -CD. For comparison, the inclusion of CUR in 2, 6-dimethyl- β -cyclodextrin (DM- β -CD) and 2-hydroxypropyl- β -cyclodextrin (HP- β -CD) was simulated. The calculated parameters included solubility parameters, binding energy, mean square displacement, radial distribution, and hydrogen bonding. The simulation results showed that DM- β -CD was most effective for the inclusion of CUR. Inclusion complexes of CUR with β -CD, DM- β -CD, and HP- β -CD were prepared by freeze-drying. The inclusion complexes were characterized using Fourier transform infrared spectroscopy, X-ray diffraction, differential scanning calorimetry, and UV-visible (UV-vis) spectra. The experimental results also showed that DM- β -CD was most effective for the inclusion of CUR, which is in agreement with the simulation results.