H–d-Phe–d-Pro–Gly methyl ester hydrochloride monohydrate

Abstract

The conformation of the title tripeptide methyl ester hydrochloride monohydrate, 1-[2-(methoxycarbonylmethylaminocarbonyl)pyrrolidin-1-ylcarbonyl]-2-phenylethanaminium chloride monohydrate, C17H24N3O4+·Cl−·H2O, is extended, but the structure cannot be classified as any typical secondary structure. Interactions through water molecules and chloride ions were formed, in addition to peptide–peptide hydrogen bonds, stabilizing the molecular packing. In comparison with the previous β-turn structure of the Phe–d-Pro–Gly analogue [Doi, Ichimiya & Asano (2007). Acta Cryst. E63, o4691], it was suggested that the difference between the chiralities of Phe and Pro residues of the title compound is important to induce the β-turn structure.