title: 13C-n.m.r. studies of the acetylation sequences in partially N-deacetylated chitins (chitosans).
abstract: Chitosans obtained under homogeneous conditions of N-deacetylation, with degrees of N-deacetylation between 46% and 94%, were depolymerised and their 125-MHz 13C-n.m.r. spectra have been interpreted. The sequence of 2-acetamido-2-deoxy-beta-D-glucopyranose (GlcNAc) and 2-amino-2-deoxy-beta-D-glucopyranose (GlcN) residues influenced the chemical shifts, and the diad and triad frequencies have been calculated. Chitosans that were N-deacetylated under homogeneous and heterogeneous conditions gave values for the diad and triad frequencies that were consistent with a random arrangement of GlcN and GlcNAc residues.
authors.affiliation: Norwegian Biopolymer Laboratory (NOBIPOL), University of Trondheim.
authors.forename: K M
authors.initials: KM
authors.lastname: Vårum
authors.forename: M W
authors.initials: MW
authors.lastname: Anthonsen
authors.forename: H
authors.initials: H
authors.lastname: Grasdalen
authors.forename: O
authors.initials: O
authors.lastname: Smidsrød
mesh_terms: D000107:Acetylation; D002240:Carbohydrate Sequence; D002686:Chitin / Q000031:analogs & derivatives* / Q000737:chemistry; D048271:Chitosan; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D015394:Molecular Structure
chemical_list: D002686:Chitin; D048271:Chitosan