Structure of N-acetyl-L-leucyl-L-prolinamide monohydrate

C13H23N3O3.H2O, Mr = 287.36, orthorhombic, P2(1)2(1)2(1), a = 6.3863 (8), b = 14.346 (2), c = 17.247 (2) A, V = 1580.1 (6) A3, Z = 4, Dx = 1.208 g cm-3, lambda(Cu K alpha) = 1.54178 A, mu = 7.04 cm-1, F(000) = 624, room temperature, final R = 0.037 for 1693 reflections with I greater than or equal to 2.5 sigma (I) and 257 variables. The peptide linkage is in a trans conformation. The pyrrolidine ring adopts a puckered C gamma-endo conformation and the leucine side chain is in a twisted [g-(tg-)] conformation. The crystal packing is stabilized by a three-dimensional network of hydrogen bonds which involve all the donor groups. The water molecule plays an important part in the crystal packing, being engaged in three hydrogen bonds with different N-acetylamide molecules.