Interaction mechanism and structure-activity relationship of hesperidin, methyl hesperidin and hesperidin methyl chalcone with ovalbumin: A comparative study

In this study, we examined the interplay mechanism and structure-activity relationships between ovalbumin (OVA) and three closely related hesperidin-based flavonoid derivatives using multispectral analysis and computer simulation. The results obtained from fluorescence spectroscopy demonstrated that Hesperidin (HSD), Methyl Hesperidin (MH), and Hesperidin Methyl Chalcone (HMC) all induced a substantial fluorescence quenching in OVA under static quenching conditions, with the fluorescence quenching intensity following the order of HMC > MH > HSD. Thermodynamic parameters and molecular docking analysis revealed that hydrogen bonding plays a pivotal role in this interaction. Furthermore, multispectral and molecular dynamics simulation analyses indicated that the binding of flavonoids induced conformational and secondary structure changes in OVA, resulting in a reduction in its hydrophobicity. Additionally, the combination of flavonoids with OVA significantly enhanced the antioxidant properties of the former. Structure-activity relationship analyses demonstrated that the methylation of the hydroxyl group at position 7 of HSD influenced its binding affinity to OVA, whereas the backbone structure (C6-C3-C6) of the flavanones (HSD and MH) contributed to an increase in the emulsifying capacity of OVA. Thus, our findings show that the slight structural differences among the three flavonoids profoundly influence their interaction mechanisms with OVA and its functional properties.