Volumetric, ultrasonic, and viscometric behaviour of l-histidine in aqueous-glucose solutions at different temperatures

Densities, ρ, ultrasonic speeds, u, and viscosities, η, of aqueous-glucose (5%, 10%, 15%, and 20% of glucose, w/w in water) and of solutions of l-histidine in aqueous-glucose solvents were measured at T = (293.15, 298.15, 303.15, 308.15, 313.15, and 318.15) K. From these experimental data, apparent molar volume, Vϕ  , limiting apparent molar volume, Vϕ∘ and the slope, Sv, apparent molar compressibility, Ks,ϕ  , limiting apparent molar compressibility, Ks,ϕ∘ and the slope, Sk  , transfer volume, Vϕ,tr∘, transfer compressibility, Ks,ϕ,tr∘, Falkenhagen coefficient, A, Jones–Dole coefficient, B, and temperature derivative of B-coefficient, dB/dT were calculated. The results are interpreted in terms of solute–solute and solute–solvent interactions in these systems. It has been observed that there exist strong solute–solvent interactions in these systems, which increase with increase in glucose concentration. It has also been observed that l-histidine act as structure-maker in aqueous-glucose solvents.

Research highlights► The study reports interactions of l-histidine with carbohydrates in aqueous media. ► Provides data to estimate physicochemical properties of proteins in these media. ► Provides better understanding biological phenomena involving l-histidine. ► Correlates physicochemical properties of l-histidine with its behavior in solution.