Abstract: A squalene/γ-cyclodextrin inclusion complex was prepared by aqueous solution method combined with freeze-drying. The inclusion complex was characterized by phase solubility method, Fourier transform infrared spectroscopy and hydrogen nuclear magnetic resonance (1H NMR), and its molecular structure was simulated. The results showed that when excess squalene was available, the molar ratio of the host to the guest in the inclusion complex was mostly 1:1. When excess γ-cyclodextrin was available, an inclusion complex with an average molar ratio of the host to the guest of 3.45:1 was formed. The molecular structure of the inclusion complex was organized by uniform linear connection of the cyclic γ-cyclodextrin molecules to each other via the chain-like squalene molecules and its tended to be stable as the molar ratio of the host to the guest increased. Because the molecular chain length of squalene is limited, the optimum host-to-guest mole ratio is theoretically 4:1. The inclusion constant increased with increasing temperature, and could reach a maximum of 1 778.086 L/mol at 55 ℃; the maximum water solubility of squalene could be increased by 309 times at this temperature. It is inferred from the change in energy that entropy increase is the main driving force for squalene molecules to enter the γ-cyclodextrin cavity.

Key words: squalene, γ-cyclodextrin, inclusion complex, molecular simulation