Novel sulfation of curdlan assisted by ultrasonication.

This study carried out a novel sulfation process on curdlan. Results document that sulfation of the polysaccharide was more effective with the assistance of ultrasonication. Ultrasonication significantly increased the DS value of samples by almost fourfold (from about 0.030 to 0.115). Evaluation of the extent of sulfation has been made using FTIR, (1)H NMR, (13)C NMR and SEC. Both FTIR and (1)H NMR spectra confirmed the occurrence of sulfation. The combined effect of ultrasonication and acid resulted in relatively small molecular weights (e.g., sample 360_360: MW approximately 49.0 kDa), as opposed to curdlan (MW approximately 807 kDa). This work contributes to better understanding of the molecular mechanism governing the sonochemical processes of polysaccharide modification with improved physicochemical properties, and potential biomedical application.