Synthesis of carboxyl cellulose sulfate with various contents of regioselectively introduced sulfate and carboxyl groups

Both sulfate and carboxyl groups are found in many glycosaminoglycans exhibiting diverse biological activities, such as heparin. Present study reports on the preparation of cellulose derivatives containing both sulfate and carboxyl groups that were regioselectively introduced into anhydroglucose units (AGU) of cellulose. The products – carboxyl cellulose sulfates (COCS) – with various contents of both functional groups were obtained by two synthesis routes. One way started with sulfation of cellulose yielding cellulose sulfate (CS) and was followed by TEMPO-mediated oxidation of CS. In another way, cellulose at first underwent TEMPO-mediated oxidation yielding carboxyl cellulose (COC). Subsequently, acetosulfation of the COC was carried out. The products were characterized by diverse analysis methods, and the amounts of both functional groups in CS, COC and COCS were determined. Finally, the biological activity of COCS was examined.