Salts containing different amino acids: Three types salts of L-arginine containing glycine, dimethylglycine or β-alanine

Recently we have discovered a new class of amino acids salts containing different amino acids. In the present paper we report synthesis, crystal structures and infrared spectra of four such salts: L-Argininium(+) dimethylglycine iodide (L-ArgH)(DMG)I (I), di-L-argininium(+) glycinium glycine triiodide monohydrate (L-ArgH)(2)(GlyH center dot center dot center dot Gly)I-3 center dot H2O (II), di-L-argininium(+) beta-alaninium beta-alanine triiodide (L-ArgH)(2)(beta-AlaH center dot center dot center dot beta-Ala)I-3 (III), and L-argininium(2+) bis-dimethylglycine diiodide (L-ArgH(2)center dot center dot center dot DMG)(DMG)I-2(IV). The salts (I-III) crystallize in P2(1)2(1)2(1), P1, P2(1) space groups, respectively, each with one formula unit in the asymmetric unit, while the salt (IV) forms in space group P2(1) with two formula units in the asymmetric unit and is pseudo-centrosymmetric. The dimeric cations (GlyH center dot center dot center dot Gly), (beta-AlaH center dot center dot center dot beta-Ala) and (L-ArgH(2)center dot center dot center dot DMG) are built by O-H center dot center dot center dot O strong hydrogen bonds with very short O center dot center dot center dot O distances. The (L-ArgH(2)center dot center dot center dot DMG) dimeric cation of the [A(1)(2+)center dot center dot center dot A(2)] type was encountered for the first time. The obtained iodide salts (I, II, III, IV) containing different amino acids can be used in medicine as regulators of thyroxine synthesis in the body. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

This paper presents the synthesis, crystal structures, and infrared spectra of four new types of amino acid salts containing different amino acids. These salts have potential applications as regulators of thyroxine synthesis in the body.