Статья

Crystal Structure and Hydrogen-Bonding System in Cellulose Iβ from Synchrotron X-ray and Neutron Fiber Diffraction

Yoshiharu NishiyamaContribution from the Department of Biomaterials Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan, Biosciences Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, and Centre de Recherches sur les Macromolécules VégétalesCNRS, affiliated with the Joseph Fourier University of Grenoble, B.P. 53, 38041 Grenoble Cedex 9, FrancePaul LanganContribution from the Department of Biomaterials Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan, Biosciences Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, and Centre de Recherches sur les Macromolécules VégétalesCNRS, affiliated with the Joseph Fourier University of Grenoble, B.P. 53, 38041 Grenoble Cedex 9, FranceHenri ChanzyContribution from the Department of Biomaterials Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan, Biosciences Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, and Centre de Recherches sur les Macromolécules VégétalesCNRS, affiliated with the Joseph Fourier University of Grenoble, B.P. 53, 38041 Grenoble Cedex 9, France

2002en

ABI

Аннотация

The crystal and molecular structure, together with the hydrogen-bonding system in cellulose I(alpha), has been determined using atomic-resolution synchrotron and neutron diffraction data recorded from oriented fibrous samples prepared by aligning cellulose microcrystals from the cell wall of the freshwater alga Glaucocystis nostochinearum. The X-ray data were used to determine the C and O atom positions. The resulting structure is a one-chain triclinic unit cell with all glucosyl linkages and hydroxymethyl groups (tg) identical. However, adjacent sugar rings alternate in conformation giving the chain a cellobiosyl repeat. The chains organize in sheets packed in a "parallel-up" fashion. The positions of hydrogen atoms involved in hydrogen-bonding were determined from a Fourier-difference analysis using neutron diffraction data collected from hydrogenated and deuterated samples. The differences between the structure and hydrogen-bonding reported here for cellulose I(alpha) and previously for cellulose I(beta) provide potential explanations for the solid-state conversion of I(alpha) --> I(beta) and for the occurrence of two crystal phases in naturally occurring cellulose.

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Идентификаторы

DOI: 10.1021/ja0257319

Цитирования и источники

Цитирований: 4Использованных источников: 0

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