Research Article: Methyl 3-O-α-l-fucopyranosyl α-d-gal­acto­pyran­oside: a synchrotron study

Date Published: February 01, 2012

Publisher: International Union of Crystallography

Author(s): Lars Eriksson, Göran Widmalm.


The title compound, C13H24O10 is the methyl glycoside of a structural element α-l-Fucp-(1→ 3)-α-d-Galp making up two thirds of the repeating unit in the capsular polysaccharide of Klebsiella K63. The conformation of the title compound is described by the glycosidic torsion angles ϕH = 55 (1)° and ψH = −24 (1)°. The hy­droxy­methyl group in the galactose residue is present in the gauche–trans conformation. In the crystal, O—H⋯O hydrogen bonds connect the disaccharide units into chains along the a-axis direction and further hydrogen bonds cross-link the chains.

Partial Text

The capsular polysaccharide (CPS) of Klebsiella K63 contains a repeating unit consisting of → 3)-α-d-GalpA–(1 → 3)-α-l-Fucp-(1 → 3)-α-d-Galp-(1 →, see: Joseleau & Marais (1979 ▶). For an investigation of the CPS S-156 from Klebsiella pneumoniae ATCC 316 46, see: Johansson et al. (1994 ▶) and of the CPS from Klebsiella pneumoniae I-1507, see: Guetta et al. (2003 ▶). For a fiber X-ray diffraction study of the Klebsiella K63 CPS, see: Elloway et al. (1980 ▶). For the synthesis, see: Baumann et al. (1988 ▶).