Interaction of flavonoid, quercetin with organized molecular assemblies of nonionic surfactant

Interaction of quercetin, one kind of flavonoid, with TritonX-100 organized molecular assemblies was investigated by electronic absorption spectra, fluorescence emission spectra, cyclic voltammetric measurements, freeze-fracture TEM (FF-TEM) images and the ab initio quantum calculation. Quercetin is located in the TritonX-100 micelles with the phenyl groups (B-ring part), which leads to the extension of π conjugation of the whole molecule and the enhancement of its ESPT fluorescence process. The embedment of two hydroxyl groups on the phenyl into a more hydrophobic microenvironment makes the oxidation peak of quercetin move to a higher potential with a decreased peak current. The binding of quercetin with TritonX-100 micelle is a spontaneous (ΔG < 0) and endothermic process (ΔH > 0), and the hydrophobic force is the main driving force for its location.