l-Leucylglycylglycine.

In the title compound, C10H19N3O4, the N- and C-termini are protonated and ionized, respectively, and the mol-ecule forms a zwitterion. The main chain is in a folded form. In the crystal, the N-terminal -NH3 (+) group hydrogen bonds to three C-terminal -COO groups and one carbonyl O atom, forming a three-dimensional network. In addition, an N-H⋯O hydrogen bond between the amide groups of the middle glycine residue and a C-H⋯O inter-action continue along the a-axis direction. The side chains of the leucyl residues form a hydro-phobic region along the a axis.