title: Single crystals of inulin.
abstract: Lamellar crystals of inulin were grown by crystallizing sharp fractions of low molecular weight inulin from dilute aqueous ethanol solutions. The crystals were analyzed using three-dimensional electron diffraction and X-ray powder diagrams. Two crystalline polymorphs were observed, depending on the hydration conditions: a hydrated form which indexed on an orthorhombic unit cell, with space group P2(1)2(1)2(1) and with cell dimensions of a = 1.670 nm, b = 0.980 nm and c (chain axis) = 1.47 nm, together with a pseudo-hexagonal semi-hydrated form with unit cell parameters a = 1.670 nm, b = 0.965 nm and c (chain axis) = 1.44 nm. These parameters, together with the density data, indicate that inulin crystallizes along a pseudo-hexagonal six-fold symmetry with an advance per monomer of 0.24 nm. The difference between the hydrated and the semi-hydrated unit cells does not seem to correspond to any change in the conformation of inulin, but rather to a variation in water content.
authors.affiliation: Centre de Recherches sur les Macromolécules Végétales (CNRS), Grenoble, France.
authors.forename: I
authors.initials: I
authors.lastname: André
authors.forename: J L
authors.initials: JL
authors.lastname: Putaux
authors.forename: H
authors.initials: H
authors.lastname: Chanzy
authors.forename: F R
authors.initials: FR
authors.lastname: Taravel
authors.forename: J W
authors.initials: JW
authors.lastname: Timmermans
authors.forename: D
authors.initials: D
authors.lastname: de Wit
mesh_terms: D002236:Carbohydrate Conformation; D003460:Crystallization; D018360:Crystallography, X-Ray; D000431:Ethanol; D007444:Inulin / Q000737:chemistry*; D008970:Molecular Weight; D012996:Solutions; D014867:Water
chemical_list: D012996:Solutions; D014867:Water; D000431:Ethanol; D007444:Inulin