Fedyanina T. The influence of biocompatible organized solutions on the physico-chemical properties of flavonoids in solution and on silica surface

It was found that the physicochemical properties of flavonoids vary in organized solutions and depend on the structure and self-organization of molecules of PVP (statistical polymer coil), HSA (globule with hydrophobic cavities), BMPA (spherical micelles) in aqueous solutions, and the degree of change is more pronounced for quercetin as the more hydrophobic compound compared to rutin. It was shown that all investigated organized solutions at pH ? 6,5 induce tautomeric keto-enol transformation of quercetin. Enol tautomer of quercetin (both molecular and anionic form) is more stable in aqueous solution. Through research of BMPA influence in a wide range of concentrations on the flavonoid physicochemical properties one of the most important chemical constants - the value of CMC was determined and the formation of spherical micelles in solution was revealed. It was found that the isotherm of BMPA adsorption on fumed silica corresponds to four-step model, and the pH-dependence of adsorption is determined by the contribution of electrostatic and hydrophobic interactions of BMPA molecules with the sorbent surface. Quercetin and rutin are adsorbed on the fumed silica from organized solutions much more effectively than from aqueous solutions due to the formation of supramolecular complexes (in solution or on the surface), and the pH-dependence of flavonoid adsorption in the composition of these complexes is determined by the sorption properties of individual PVP, HSA and BMPA.