13C CP/MAS NMR spectra of poly-β-D(1 → 4) mannose: mannan
- 1 July 1990
- journal article
- research article
- Published by Canadian Science Publishing in Canadian Journal of Chemistry
- Vol. 68 (7) , 1192-1195
- https://doi.org/10.1139/v90-184
Abstract
13C solid-state NMR spectra (CP/MAS) were recorded for mannan polymorphs: mannan I ("ivory nut") and mannan II (Codiumfragile). These pure mannans, poly-β-(1 → 4) mannopyranose, show a single resonance for each carbon of the chemical repeat unit. This is the expected result based on the crystalline P212121 and 1222 symmetries. The T1 values were also recorded and the results are compared to those for cellulose obtained from the literature. The much lower mobility of C-6, even in noncrystalline mannan, compared to native cellulose is attributed to the epimeric difference at C-2 between cellulose and mannan allowing intramolecular hydrogen bonding in the former but not the latter. Keywords: mannan, solid state NMR, T1 relaxation, polysaccharide, ivory nut.This publication has 0 references indexed in Scilit: