Structure of N-gamma-L-glutamyl-L-cysteine ethyl ester monohydrate.

C10H18N2O5S.H2O, Mr = 296.39, monoclinic, P2(1), a = 19.600 (1), b = 7.480 (1), c = 5.061 (1) A, beta = 94.74 (1) degree, V = 739.445 (1) A3, Z = 2, Dm = 1.31, Dx = 1.331 g cm-3, Cu K alpha, lambda = 1.54178 A, mu = 21.4 cm-1, F(000) = 316, room temperature, R = 0.057 for 1263 reflections. The molecule adopts an extended form. The molecules are arranged so as to form double molecular sheets parallel to the bc plane through some hydrogen bonds.