Studies on the solvation of amino acids in ethanol and water mixtures

In order to look at the effects of different mixed solvents on amino acids, the compressibility values and the solvation numbers of different amino acids (glycine, alanine, proline, valine, histidine and arginine) in different ethanol—water mixtures have been determined using an ultrasonic interferometer. The changes in the compressibility values and solvation numbers of the amino acids with decreasing water concentration indicate some interesting features and can be explained on the basis of a decrease in the number of solvent molecules, structural rearrangement and preferential solvation of Zwitterions.