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X ray diffraction study of sulfuric nitric and halogen acid salts of chitosan


, : X ray diffraction study of sulfuric nitric and halogen acid salts of chitosan. Carbohydrate Research 160: 425-433

Chitosan {poly-[(1 .fwdarw. 4)-.beta.-D-glucosamine]}, the deacetylation product of chitin, is considered to be a promising bioresource, because unlike chitin, it is the resulting salts were studied by X-ray fiber diffraction; salts formed with HNO3, HBr, and HI each gave a distinct pattern that suggested retention of the two-fold, helical conformation of untreated chitosan. Patterns of salts prepared with HF, HCl, and H2SO4 differed substantially, showing helical repeats of 40.73 .ANG. Stereochemical analysis suggests that the last 3 salts form either left- or right-handed helices that have 8 residues in 3 turns. These 3 salts have identical unit-cell dimensions, despite differing anion sizes.

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