Hydration of neutral amino acids in different ionic forms

The content and state of water in samples of neutral amino acids (glycine, valine, and phenylalanine) were determined by IR spectroscopy. The hydratio n characteristics of the cations, anions, and bipolar ions of the amino aci ds were compared. Hydration series were constructed. It was shown that the degree of hydration of amino acids is determined by the nature of the ionic form: it is characterized by the highest and lowest values for the anions of the neutral amino acids (except glycine) and bipolar ions, respectively. A high degree of hydration of glycine in the cationic form was attributed to the specific nature of the side group of this amino acid.