Enthalpy characteristics of L-asparagine interaction with glycerol, ethylene glycol, and 1,2-propylene glycol in aqueous solutions

Integral dissolution enthalpies Delta(sol) H (m) of L-asparagine in the mixtures of water with glycerol, ethylene glycol, and 1,2-propylene glycol at the concentration of organic solvents up to 0.24 mole fraction were measured by the calorimetry method. The standard enthalpies of dissolution (Delta(sol) H (0)) and transport (Delta(tr) H (0)) of amino acids from water to the mixed solvents were derived. The calculated enthalpy coefficients of the molecule pair interactions of L-asparagine-cosolvent are positive, except for the amino acid-glycerol-water system. The data obtained are interpreted in terms of prevalence of different types of interactions in solution and effect of the cosolvent nature on the thermochemical characteristics of the L-asparagine dissolution.