Standard Enthalpies of Formation of Glycyl-L-tyrosine and Its Dissociation Products in Aqueous Solutions

The enthalpies of dissolution of crystalline glycyl-L-tyrosine in water and in aqueous potassium hydroxide at 298.15 К were determined by the direct calorimetric method. The measurements were performed on a calorimetric unit with automatic recording of the temperature–time curve. The standard enthalpies of combustion and formation of glycyl-L-tyrosine were calculated by the additive group method based on group systematics with classification of fragments of the type of Benson classification, with the effect of the initial environment for atoms included in calculation. The standard enthalpies of formation of dipeptide and the products of its dissociation in aqueous solution were calculated.