Methyl 3-O-α-d-mannopyranosyl β-d-glucopyran-oside tetra-hydrate.

The title compound, C(13)H(24)O(11)·4H(2)O, forms extended hydrogen-bonded networks. These are present between disaccharides, but not as inter-residue hydrogen bonds, as well as to water mol-ecules that in addition form an inter-molecular chain of hydrogen bonds. The conformation of the disaccharide is described by the glycosidic torsion angles ϕ(H) = -34° and ψ(H) = -5°. Macroscopically, the disaccharide was observed to be hygroscopic.