A Water Environment Forces Retinyl Palmitate to Create Self-Organized Structures in Binary Solvents

Abstract

The interaction between retinyl palmitate molecules and their environment in binary water/p-dioxane and water/isopropyl alcohol solvents was studied under different solvent polarities. The binary solvent polarities were changed by changing the molar ratios of water to p-dioxane (or isopropyl alcohol). The fluorescence emission and fluorescence excitation spectra were analyzed. In binary solvents, the interaction between retinyl palmitate molecules and environments of different polarities leads to the self-organization of retinyl palmitate, and as a result, different fluorescence centers are created. The similar fluorescence properties of these centers in different binary solvents were interpreted as a water driving force inducing the self-organization of retinyl palmitate. The possible consequences of this phenomenon for misleading interpretation of model studies of retinol interaction with retinol transporting proteins are also discussed.