title: Bergenin monohydrate from the rhizomae of Astilbe chinensis.
abstract: The title compound, 4-methoxy-2-[(1S,2R,3S,4S,5R)-3,4,5,6-tetrahydro-3,4,5-trihydroxy-6-(hydroxymethyl)-2H-pyran-2-yl]-alpha-resorcylic acid delta-lactone monohydrate, C(14)H(16)O(9).H(2)O, is a C-glucoside of 4-O-methylgallic acid which has antiasthmatic, antitussive, anti-inflammatory, antifungal, anti-HIV and antihepatotoxic activity. The molecule is composed of three six-membered rings: an aromatic ring, a glucopyranose ring and an annellated delta-lactone ring. The glucopyranose ring exhibits only small deviations from an ideal chair conformation. The annellated delta-lactone ring possesses the expected half-chair conformation. There is one intra- and six intermolecular hydrogen bonds which form an extensive hydrogen-bonding network within the crystal.
authors.affiliation: Institute of Materia Medica, Zhejiang Academy of Medical Sciences, Hangzhou 310029, People's Republic of China.
authors.forename: Yi-Ping
authors.initials: YP
authors.lastname: Ye
authors.forename: Hong-Xiang
authors.initials: HX
authors.lastname: Sun
authors.forename: Yuan-Jiang
authors.initials: YJ
authors.lastname: Pan