Interaction mechanism of cholesterol/?-cyclodextrin complexation by combined experimental and computational approaches

Authors：Dai, Yunxiang; Zhong, Jinfeng; Li, Jiaqi; Liu, Xiong; Wang, Yonghua^*; Qin, Xiaoli^*

Source：Food Hydrocolloids, 2022, 130: 107725.

DOI：10.1016/j.foodhyd.2022.107725

• Cholesterol
• ?-cyclodextrin inclusion complex
• Non-covalent interaction
• Interaction region indicator
• Density function theory
• Energy decomposition
• Conformational search

It is crucial to accurately describe non-covalent weak interactions between the components of cholesterol/ beta-cyclodextrin inclusion complex in the modulation of its stability. Experimental and theoretical infrared spectra confirmed that the inclusion complex was successfully prepared. Phase solubility studies suggested the formation of 1:1 stoichiometric inclusion complex of cholesterol with beta-CD. The inclusion complex showed higher decomposed temperature (327.3 degrees C) than physical mixture (321.6 degrees C), indicating improved thermal stability of inclusion complex. Conformational search and density functional theory calculations were performed to find the most stable conformation with the lowest complexation energy (-129.66 kJ/mol). Dispersion energy from van der Waals (-283.31 kJ/mol) contributed greatly on total bonding energy (- 204.72 kJ/mol). The bond lengths of hydrogen bonds (O127...H221 and O220...H107) were 1.77 and 1.62 angstrom, respectively. Van der Waals and hydrogen bonds were necessary to drive spontaneous formation and maintain the stability of inclusion complex. This study revealed a deep insight into the formation mechanism of cholesterol/beta-CD inclusion complex using computational and experimental approaches, providing theoretical basis for the removal of cholesterol from hydrocolloid-containing systems.

• Institution
  西南大学