title: Swertisin dihydrate.
abstract: The title compound, 6-C-glucopyranosyl-7-O-methylapigenin dihydrate, C(22)H(22)O(10).2H(2)O, is a natural C-glucosylflavone. The flavone skeleton is almost planar, the dihedral angle between the pyran moiety and the 4-hydroxyphenyl ring being 9.8 (3) degrees. The basal plane of the pyranosyl ring of the glucose moiety is almost perpendicular to the benzopyran ring system. The flavone skeletons are stacked along the a axis, forming layers parallel to (001). Between these hydrophobic layers, the glucose groups and water molecules of crystallization are connected via O-H...O hydrogen bonds, forming hydrophilic layers.
authors.affiliation: Department of Chemistry, Keio University, Hiyoshi 4-1-1, Kohoku-ku, Yokohama 223-8521, Japan. ohba@flet.keio.ac.jp
authors.forename: Shigeru
authors.initials: S
authors.lastname: Ohba
authors.forename: Kumi
authors.initials: K
authors.lastname: Yoshida
authors.forename: Tadao
authors.initials: T
authors.lastname: Kondo
mesh_terms: D047309:Flavones / Q000737:chemistry*; D006860:Hydrogen Bonding; D008958:Models, Molecular; D008968:Molecular Conformation; D009005:Monosaccharides / Q000737:chemistry*
chemical_list: C500521:6-C-glucopyranosyl-7-O-methylapigenin dihydrate; D047309:Flavones; D009005:Monosaccharides