Date Published: June 01, 2012
Publisher: International Union of Crystallography
Author(s): Katalin Selmeczi, Patrick Gizzi, Emmanuel Wenger, Bernard Henry.
http://doi.org/10.1107/S1600536812023562
Abstract
In the title compound {systematic name: 4-[2-({N-[(2S)-2-ammoniopropanoyl]glycyl}amino)ethyl]-1H-imidazol-3-ium dichloride}, C10H19N5O22+·2Cl−, the pseudo-tripeptide l-alanylglycylhistamine is protonated at both the terminal amino group and the histidine N2 atom. The resulting positive charges are neutralized by two chloride anions. In the crystal, the organic cation adopts a twisted conformation about the CH2—CH2 bond of histamine and about the C—N bond in the main chain, stabilized by a short intramolecular C—H⋯O contact. In the crystal, N+—H⋯O and N+—H⋯Cl− hydrogen bonds link the molecules into infinite sheets parallel to the (100) plane. The stacking of these sheets along the a axis is supported by Namide—H⋯Cl− hydrogen bonds.
Partial Text
For the complexation ability of l-Ala-Gly-HA, see: Gizzi et al. (2005 ▶). For bond lengths and angles in other oligopeptides, see: Itoh et al. (1977 ▶); Selmeczi et al. (2008 ▶). For discussion of hydrogen bonding, see: Steiner (2002 ▶). For the synthesis of pseudo-peptides, see: Henry et al. (1993 ▶). For the definition of torsion angles in peptides, see: IUPAC–IUB Commission on Biochemical Nomenclature (1970 ▶).
Source:
http://doi.org/10.1107/S1600536812023562