Interactions of tripeptide with glucose in aqueous solutions at various temperatures: A volumetric and ultrasonic study

Solution densities and speeds of sound of tripeptide (gly(gly)2) in aqueous and aqueous glucose solutions have been determined at temperatures: 288.15, 293.15, 298.15, 303.15 and 308.15 K. These solution densities and speeds of sound were used to calculate apparent molar volume at infinite dilution (Vϕ0) transfer partial molar volume (ΔtrVϕ0) apparent molar adiabatic compressibility at infinite dilution (Kϕ,S0), and its transfer values (ΔtrKϕ,S0), at infinite dilution. These parameters have been discussed in terms of solute–solvent interactions. We have also attempted to examine the temperature and concentration dependence of such interactions. Contributions of peptide group (–CONH–) to Vϕ0 and Kϕ,S0 in aqueous solution at 298.15 K are also estimated by comparing with the data in the literature and of α,ω-amino acids. Also group contributions to transfer volumes at temperatures: 288.15, 298.15 and 308.15 K from water to aqueous glucose solutions have also calculated.