Optical Spectroscopy Study of the Interaction Between Quercetin and Human Serum Albumin

Medical Physics Division, Biophysics Department, Collegium Medicum of Nicolaus Copernicus University Jagiello«ska 13, 85-067 Bydgoszcz, Poland Optical methods are very useful for the study on behavior of molecules in albumin-containing solutions. The interaction between quercetin (QUE) and human serum albumin (HSA) under physiological conditions was investigated by the methods of UV-Vis absorption and uorescence spectroscopy. Fluorescence data show that enhancing of quercetin uorescence in the presence of HSA is the result of formation of the HSA-QUE complex. On the basis of uorescence data, the binding a nity constant of quercetin to HSA is determined. In this paper we have attempted to perform a kinetic study of the oxidation of quercetin in presence of human serum albumin by absorption spectroscopy. It has been shown that quercetin easily oxidizes at pH 7.4. The addition of HSA to quercetin solution induces changes in the absorption spectrum. In the human serum albumin solution, the time of quercetin oxidation is longer than in the case of quercetin diluted in phosphate bu ered saline. Human albumin also contributes to stabilization of quercetin. These results suggest that HSA prevents degradation of quercetin in blood. DOI: 10.12693/APhysPolA.125.A-57