NMR characterization of N-benzyl sulfonated derivatives of chitosan

Chitosan was reacted with 2-formylbenzene sodium sulfonate and 4-formylbenzene sodium disulfonate in the presence of sodium cyanoborohydride to yield N-benzyl derivatives. One-dimensional and two-dimensional NMR spectroscopy were used for the characterization of both products. This study allowed us to assign all proton and carbon signals and confirmed the structure. H-1 NMR spectra showed that the parent polymer is 22% acetylated and that the overall degree of substitution is 83% and 47% for the monosulfonic and disulfonic derivatives, respectively. (C) 1997 Published by Elsevier Science Ltd.