Mechanism and structure studies of cinnamaldehyde/cyclodextrins inclusions by computer simulation and NMR technology

This work aims to explore the inclusion mechanism and structure of cinnamaldehyde (CNMA) and cyclodextrins (CDs), and to provide some theoretical information for the application of CNMA and its inclusion. In this study, we prepared three kinds of inclusion and investigated the mechanism and structure by theory and experiment. Molecular docking and dynamical simulations presented a stable 1:1 inclusion complex and the visual structure model. The structural features indicated that the benzene ring of CNMA was enclosed in the hydrophobic cavity of CDs, which were consistent with the results of 1H NMR, 2D-ROESY, Fourier transform infrared spectroscopy. The inclusion mechanism studies showed that the inclusion process was driven mainly by enthalpy with the binding constant following the order of DM (dimethyl) > HP (hydroxypropyl) > β-CD. Moreover, the inclusion complex showed an advantageous water solubility and dissolution rate compared with CNMA.