Determination of the degree of N-acetylation and the distribution of N-acetyl groups in partially N-deacetylated chitins (chitosans)by high-field n.m.r. spectroscopy* (Record no. 48392)

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Transcribing agency CICY
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Classification number (OCLC) (R) ; Classification number, CALL (RLIN) (NR) B-14198
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Title Determination of the degree of N-acetylation and the distribution of N-acetyl groups in partially N-deacetylated chitins (chitosans)by high-field n.m.r. spectroscopy*
490 0# - SERIES STATEMENT
Volume/sequential designation Carbohydrate Research, 211(1), p.17-23, 1991
520 3# - SUMMARY, ETC.
Summary, etc. The composition and sequence of 2-acetamido-2-deoxy-B-D-glucose (GlcNAc)and 2-amino-2- deoxy-/?-o-glucose (GlcN)residues in partially N-deacetylated chitosans, prepared under homogeneous and heterogeneous conditions, have been determined by 'H-n.m.r. spectroscopy. It was necessary to depolymerise the chitosan slightly by treatment with nitrous acid before spectroscopy. A sequence-dependent deshielding of H-l of the GlcNAc residues made it possible to determine the proportions of the four possible diads. Chitosan prepared by N-deacetylation under homogeneous conditions gave values for the diad frequencies that were roughly consistent with a random distribution of the N-acetyl groups. Samples prepared under heterogeneous conditions have a frequency of the GlcNAc-GlcNAc diad slightly higher than for a random (Bernoullian)distribution. The chitosans, prepared under both homogeneous and heterogeneous conditions, with a degree of acetylation of 50(percent)were soluble at neutral pH.
700 12 - ADDED ENTRY--PERSONAL NAME
Personal name Vaum, K.M.
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Personal name Anthonsen, M.W.
700 12 - ADDED ENTRY--PERSONAL NAME
Personal name Grasdalen, H.
700 12 - ADDED ENTRY--PERSONAL NAME
Personal name Smidsrad, O.
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Uniform Resource Identifier <a href="https://drive.google.com/file/d/1pIBUUrN8rDHul6xdmrUeXA3N1s5ggYOS/view?usp=drivesdk">https://drive.google.com/file/d/1pIBUUrN8rDHul6xdmrUeXA3N1s5ggYOS/view?usp=drivesdk</a>
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  Clasificación local     Ref1 CICY CICY Documento préstamo interbibliotecario 25.06.2025   B-14198 25.06.2025 25.06.2025 Documentos solicitados