Mechanism of Mutual Incorporation of l-Isoleucine and Isomorphic Amino Acids in Batch Crystallization

We explored the mutual incorporation tendency of l-isoleucine and isomorphic amino acids in cooling crystallization conducted in water. In most cases, a guest amino acid (an impurity amino acid) with side chain longer than that of l-isoleucine was easily incorporated in l-isoleucine. In this case, a solid solution was formed and the c-axis of l-isoleucine structure was stretched. Furthermore, the crystal growth was inhibited. Using these results, a mechanism for mutual incorporation of these amino acids was proposed.