Interaction mechanism of flavonoids and zein in ethanol-water solution based on 3D-QSAR and spectrofluorimetry.

Zein has the potential application of establishing the delivery systems for flavonoids. But there are few reports about the effect of the molecular structures of flavonoids on their interaction with zein. In this study, the binding behaviour of 21 flavonoids and zein was investigated by spectrofluorimetry. The corresponding 3D-QSAR model was also established by Topomer CoMFA method, whose steric and electrostatic field analysis could explain the binding performance of the tested flavonoids with zein. The fluorescence analysis suggested that the flavonoids could interact with zein by forming the complex at the molar ratio of 1. The flavonoids with glucosyl groups at ring A exhibited the outstanding binding capacity with zein, and their binding process with zein was driven by hydrophobic force. The synchronous and 3D fluorescence spectra showed that there was no apparent change in the microenvironment surrounding the tyrosine residues of zein during the interaction.