Acta Crystallographica Section E: Crystallographic Communications (Apr 2015)
The tripeptide N-Cbz-βGly-Gly-Gly-Obz
Abstract
The title peptide, N-benzyloxycarbonyl-β-glycylglycylglycine benzyl ester, C22H25N3O6, contains a non-proteinogenic amino acid residue, β-glycine, which is a homologated analogue of glycine. In the molecular structure, β-glycine adopts an extended conformation with a trans conformation about its Cβ—Cα bond. The second glycine residue adopts an extended conformation while the third glycine residue adopts a helical conformation. In the crystal, three N—H...O hydrogen bonds, two involving the same carbonyl O atom as acceptor, results in an infinite two-dimensional network parallel to the bc plane.
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