H-d-Phe-d-Pro-Gly methyl ester hydro-chloride monohydrate.

The conformation of the title tripeptide methyl ester hydro-chloride monohydrate, 1-[2-(methoxycarbonylmethylaminocarbonyl)pyrrolidin-1-ylcarbonyl]-2-phenylethanaminium chloride monohydrate, C(17)H(24)N(3)O(4) (+)·Cl(-)·H(2)O, 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.