Synthesis and characterisation of dextran and pullulan sulphate Original Research Article

Dextrans and pullulans of different molar masses in the range of 104–105 g/mol were sulphated via a SO3–pyridine complex. The degree of substitution achieved was DS=2.4 and DS=1.4 for dextran sulphate and DS=2.0 and DS=1.4 for pullulan sulphate, respectively. Confirmation of sulphation was given by FTIR spectroscopy. Asymmetrical SO and symmetrical COS stretching vibrations were detected at 1260 and 820 cm−1. Reactivity of the polysaccharide C-atoms was determined by 13C NMR spectroscopy: For dextran this was C-3>C-2>C-4, while for pullulan it was C-6>C-3>C-2>C-4.