L-phenylalanyl-L-tryptophan 0.75-hydrate

The title compound, C20H21N3O3 center dot 0.75H(2)O, 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.