Structural features of sulfated chitosans

Chitosan sulfates prepared by different methods were analyzed by C-13 NMR spectroscopy. It was shown that the sulfation conditions of chitosan essentially affect the position and degree of substitution with sulfate in derivatives of chitosan. Sulfated products obtained under homogeneous conditions are characterized by more heterogeneity and they have to be considered as copolymers of chitosan 6-O-monosulfate and 3,6-O-disulfate, whereas those produced by semi-heterogeneous synthesis may be considered preferentially as chitosan 3,6-O-disulfate. Copyright (C) 1997 Elsevier Science Ltd. All rights reserved.