コハク酸,グルタル酸,マレイン酸と数種のα-アミノ酸との固体複合体の形成

抄録

Solid complex formation of organic acids with several a-amino acid was studied by X-ray powder diffraction, infrared spectroscopy and differential thermogravimetry.
Succinic acid forms solid complexes with (±)-a-amino-n-butyric acid, (±)-valine and (±)- norvaline in a molar ratio of 1: 2, while glutaric acid forms solid complexes with glycine and (+)-a-amino-n-butyric acid in a molar ratio of 1: 1. The complexes of succinic acid and glutaric acid have a peritectic point. Maleic acid forms solid complexes with glycine, (±)alanine, (±)-a-amino-n-butyric acid, (±)-valine, (±)-isoleucine and (±)-leucine in a molar ratio of 1: 1. The complex of glycine has a peritectic point.
It was inferred that that the solid complexes of succinic acid, glutaric acid and the complex of maleic acid with (±)-leucine were formed through intermolecular hydrogen bond between the carboxyl group in organic acid and the carboxyl group of amino acid, while the complexes of maleic acid with the amino acids except (±)-leucine were formed by proton-transfer from the carboxyl group in organic acid to the carboxylate ion of the amino acids.