Thermodynamic Study of Some Amino Acids, 2-Aminopropanoic Acid, 2-Amino-3-methylbutanoic Acid, 2-Amino-4-methylpentanoic Acid, and 2-Amino-3-phenylpropanoic Acid in Aqueous Saccharide Solutions at Different Temperatures: Volumetric and Ultrasonic Study

Abstract

Knowledge of thermodynamic properties of amino acids in aqueous medium can provide valuable information about the stabilization mechanism of proteins. In this study, we report the density and speed of sound of some amino acids (2-aminopropanoic acid, 2-amino-3-methylbutanoic acid, 2-amino-4-methylpentanoic acid, and 2-amino-3-phenylpropanoic acid) in aqueous fructose, d-(+)-cellobiose, and d-melezitose solutions (0.1 mol·kg−1) at (293.15, 298.15, 303.15, and 308.15) K. From these data, the apparent molar volume and apparent molar adiabatic compressibility have been evaluated. The partial molar volume, partial molar adiabatic compressibility, and their corresponding transfer functions were calculated. These results were used to interpret the type of interactions occurring in the ternary mixtures using the cosphere overlap model. The concentration and temperature dependence of solute−solute and solute−solvent interactions in the present study was also discussed.