Density and Viscosity Study of Interactions of Some Amino Acids in Aqueous Solutions of Sodium Benzoate

Abstract

The density (ρ) and viscosity (η) of three amino acids, glycine, l-alanine, and l-valine, have been determined as a function of amino acid concentration in aqueous solutions of 0.1011, 0.3088, and 0.5245 mol·kg–1 sodium benzoate at temperatures 303.15, 308.15, and 313.15 K. Apparent molar volumes (V ϕ), limiting values of apparent molar volumes (V 0 ϕ), and transfer volumes (Δt V 0 ϕ) have been calculated from the density data. The viscosity data could be fit to the Jones–Dole equation, and B coefficients and variation of B with temperature dB/dT were obtained at different concentrations and temperatures. Free energies of activation of the solvent (Δμ1 0≠) and solute (Δμ2 0≠) were also calculated by application of the Eyring transition-state theory. The obtained thermophysical data have been interpreted in terms of the structure of the amino acids and their interactions with the sodium benzoate solution.

Expliciting the {Ciprofloxacin Hydrochloride + (Glycine/l-Isoleucine)} Interactions in Aqueous Solution over the Temperature range T = 288.15–323.15 K and at Pressure p = 1 × 105 Pa: Volumetric, Acoustic, Calorimetric, and Absorption studies

“…Kumar et al 16 reported that in the aqueous solution of ampicillin drug, the hydration behavior of dipeptides of alanine gets modulated due to the dominance of ion−hydrophilic as well as hydrophilic−hydrophilic interactions. Haghani et al 17 on the behavior of amino acids in aqueous solutions of vitamin B6, Ma et al 18 found that ion−ion, ion−hydrophilic, and hydrophilic−hydrophilic interactions predominate. Thus, it may be quite interesting to study the intermolecular interactions among CFX and amino acids (glycine (GLY) and L-isoleucine (ILU)) in aqueous solutions as a function of temperature and concentration using volumetric, acoustic, calorimetric, and spectral studies.…”

“…Kumar et al reported that in the aqueous solution of ampicillin drug, the hydration behavior of dipeptides of alanine gets modulated due to the dominance of ion–hydrophilic as well as hydrophilic–hydrophilic interactions. Haghani et al from the investigations on amino acids in the aqueous solutions of sodium benzoate found that the hydrophobic–hydrophobic and ion–nonpolar group interactions dominate. From the volumetric and viscometric studies on the behavior of amino acids in aqueous solutions of vitamin B6, Ma et al found that ion–ion, ion–hydrophilic, and hydrophilic–hydrophilic interactions predominate.…”