title: Advances on selective C-6 oxidation of chitosan by TEMPO.
abstract: The specific C-6 oxidation by TEMPO of chitosan and chitosan derivatives were studied to obtain tailored bioactive biopolymers. The modifications on chitosan presented many difficulties and showed the adverse effect of the amine moieties of chitosan on this reaction. Thus, protections of the amino groups by N-acetylation or N-phthaloylation were studied and followed by the C-6 specific oxidations of the resulting polymers. The desired 6-carboxychitosan could not be obtained after deprotection; the reactions with TEMPO led to degradation of the polymers. The specific oxidation of a potentially bioactive derivative of chitosan was then achieved by the oxidation of a quaternized chitosan: N, N, N-trimethylchitosan. N, N, N-Trimethyl-6-carboxychitosan was characterized by FTIR spectroscopy, 1H, and 13C NMR spectroscopy.
authors.affiliation: Université Bordeaux 1, INRA, CNRS, UMR 5103 US2B, 351 cours de la Libération, F-33405 Talence, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Bordenave
authors.forename: Stéphane
authors.initials: S
authors.lastname: Grelier
authors.forename: Véronique
authors.initials: V
authors.lastname: Coma
mesh_terms: D001704:Biopolymers / Q000737:chemistry*; D002236:Carbohydrate Conformation; D002384:Catalysis; D048271:Chitosan / Q000138:chemical synthesis / Q000737:chemistry*; D003497:Cyclic N-Oxides / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D010084:Oxidation-Reduction; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D001704:Biopolymers; D003497:Cyclic N-Oxides; D048271:Chitosan; C003959:TEMPO