Abstract
Three β-chitin structures [anhydrous, di-hydrate, mono-ethylenediamine (EDA)] recently determined by synchrotron X-ray and neutron fiber diffraction were reviewed from the viewpoint of molecular interactions. Both water and EDA molecules interact with the chitin chains through multiple hydrogen bonds. When water complexes with chitin, the hydrogen bonding pattern rearranges with the replacement of an intrachain chitin hydrogen bond by a stronger hydrogen bond between chitin and water, with an associated reduction in the degrees of freedom; the water oxygen is a much stronger acceptor than the O5 ring atom. The behavior of hydrogen exchange by deuterium supports this interpretation. EDA-molecules change the conformation of hydroxymethyl group from gg to gt, accompanied by changes in hydrogen bonds due to the strong accepting ability of the EDA nitrogen atoms. Some important interactions are in common with experimental crystallographic results of cellulosic crystals and of molecular dynamics studies. These new insights into solid-solvent interactions are valuable in understanding molecular interactions in other polysaccharides-solvents system in solution or on surface.
Original language | English |
---|---|
Pages (from-to) | 1007-1014 |
Number of pages | 8 |
Journal | Cellulose |
Volume | 21 |
Issue number | 2 |
DOIs | |
State | Published - Apr 2014 |
Funding
Acknowledgments We thank beamline D19 at the Institut Laue-Langevin, BL38B1 and BL40B2 at SPring-8 for use of facilities. We thank the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) for collecting samples of L. satsuma using a remotely operated vehicle, Hyper-Dolphin. PL was partly supported by Genomic Science Program, Office of Biological and Environmental Research, US Department of Energy, under FWP ERKP752 and the US Department of Energy, managed by UT-Battelle, LLC under contract No. DE-AC05-00OR22725. PL acknowledges support by the Scientific User Facilities Division, Office of Basic Energy Sciences. YO was supported by grant-in-aids for JSPS research fellow (23-2362).
Keywords
- Crystallosolvates
- Hydrogen bond
- Hydroxymethyl group
- Molecular interaction
- Structure analysis
- β-chitin