High-efficiency formation mechanism of mangiferin/γ-cyclodextrin complex

Cyclodextrins (CDs) are widely applied to improve the aqueous solubility and stability of nutraceuticals with the advantages of high safety and low cost. In this study, the binding capacities of CDs (α-CD, β-CD, maltosyl-β-CD, hydroxypropyl-β-CD and γ-CD) with mangiferin were compared by the phase solubility method and isothermal titration calorimetry. γ-CD could completely encapsulate mangiferin at the molar ratio of 1:1, which coincided with the molecular docking and ONIOM calculation results that γ-CD had the lowest interaction energy with mangiferin. The independent gradient model (IGM) visualized the intermolecular non-covalent binding and electrostatic potential around mangiferin during interaction. By complexing with γ-CD, mangiferin was molecularly dispersed in the matrix of γ-CD with its aromatic ring in the hydrophobic cavity. Compared with pure mangiferin, the mangiferin/γ-CD complex exhibited the stronger chemical antioxidant activities. The obtained result can promote the application of mangiferin and γ-CD in foods.