title: Crystal structure of methyl 3-O-beta-D-glucopyranosyl-beta-D-glucopyranoside (methyl beta-D-laminarabioside) monohydrate.
abstract: Crystals of methyl 3-O-beta-D-glucopyranosyl-beta-D-glucopyranoside (methyl beta-D-laminarabioside) belong to the orthorhombic system, space group P2(1)2(1)2, with a = 14.548(2), b = 24.252(7), c = 4.938(1) A, and Z = 4. The crystal structure was solved by the direct method and refined by the full-matrix least-squares procedure to an R-value of 0.062 for 1099 observed reflections in the X-ray data. The molecular structure is similar to that of beta-D-laminarabiose. The torsional angles around the glycosidic bonds are influenced by both the existence of an intramolecular hydrogen bond at O-4'... O-5 and the exo-anomeric effect. In the nonreducing residue, the exocyclic O-5-C-5-C-6-O-6 and C-4-C-5-C-6-O-6 torsional angles are (+)gauche and trans, respectively, whereas the corresponding torsional angles in the reducing residue are (-)gauche and (+)gauche. One water molecule cocrystallizes with each disaccharide, and the crystal structure is stabilized mainly by intra- and inter-molecular hydrogen bonds involving water molecules.
authors.affiliation: Faculty of Technology, Tokyo University of Agriculture and Technology, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Noguchi
authors.forename: K
authors.initials: K
authors.lastname: Okuyama
authors.forename: S
authors.initials: S
authors.lastname: Kitamura
authors.forename: K
authors.initials: K
authors.lastname: Takeo
mesh_terms: D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D004187:Disaccharides / Q000737:chemistry*; D005936:Glucans / Q000737:chemistry; D005960:Glucosides / Q000737:chemistry*; D006860:Hydrogen Bonding; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011135:Polysaccharides, Bacterial / Q000737:chemistry; D014867:Water / Q000737:chemistry; D014961:X-Ray Diffraction; D047071:beta-Glucans
chemical_list: D004187:Disaccharides; D005936:Glucans; D005960:Glucosides; D011135:Polysaccharides, Bacterial; D047071:beta-Glucans; D014867:Water; C014637:laminaribiose; C080151:methyl laminarabioside; C038459:curdlan