title: Crystal transition between hydrate and anhydrous (1→3)-β-D-xylan from Penicillus dumetosus.
abstract: The crystal structures of hydrated and anhydrous (1→3)-β-d-xylan and the crystal transition between them were investigated. Highly crystalline samples of (1→3)-β-d-xylan were prepared from a siphoneous green alga, Penicillus dumetosus. The crystal structure was analyzed using synchrotron X-ray diffraction and solid-state (13)C NMR spectroscopy. The hydrated form was converted to the anhydrous form with contraction in both the a-axis and c-axis directions, and the crystallinity decreased considerably at the same time. The crystal transition between hydrated and anhydrous (1→3)-β-d-xylan was monitored using synchrotron X-ray diffraction under controlled relative humidity. The transition took place at certain transition points, and was accompanied by a large hysteresis. From the difference in the weight and unit-cell volume at the transition points, the number of water molecules in the hydrated form was estimated as one per xylose residue.
authors.affiliation: Department of Biomaterials Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan.
authors.forename: Kayoko
authors.initials: K
authors.lastname: Kobayashi
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kimura
authors.forename: Laurent
authors.initials: L
authors.lastname: Heux
authors.forename: Masahisa
authors.initials: M
authors.lastname: Wada