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Cross-polarization/magic-angle spinning 13C-nmr of (1 → 6)-β-D-glucan (pustulan): Mechanism of gelation

✍ Scribed by Arthur J. Stipanovic; Paul J. Giammatteo; Stephen B. Robie

Publisher
Wiley (John Wiley & Sons)
Year
1985
Tongue
English
Weight
516 KB
Volume
24
Category
Article
ISSN
0006-3525

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✦ Synopsis

Synopsis

' C n m r has been employed to probe the molecular conformation and crystal structure of (1+6)-P-~-glucan (pustulan) in the solution, gel, and solid states. CP/MAS Y-nmr spectra recorded for partially crystalline solid pustulan display a resonance near 82 ppm that is absent in solution spectra. The intensity and peak width of this resonance were found to depend on relative crystallinity as determined by x-ray diffraction. CP/ MAS spectra of aqueous pustulan gels also exhibit the 82-ppm resonance, suggesting that the gelation mechanism may involve microcrystalline junction zones. Since the 82-ppm resonance is absent in the CP/MAS spectrum of the (l46)-P-linked dimer gentiobiose, we tentatively conclude the crystal structure of this dimer does not adequately model the yet undetermined structure of pustulan.

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