L-Phenylalanyl-L-tryptophan 0.75-hydrate.

The title compound, C20H21N3O3.0.75H2O, crystallizes as exceedingly thin fibers. The crystal packing arrangement is related to those of other hydrophobic dipeptides with phenylalanine residues, but the structure has pseudo-tetragonal symmetry in an orthorhombic space group with four peptide molecules and three water molecules in the asymmetric unit.