ABSTRACT
Chitosan oligosaccharide(COS)is the N-acetyl-D-glucosamine and D-glucosamine oligomer linked to β(1→4)glycoside bond, which is an amino oligosaccharide with positive charge. GOS can be prepared via the deacetylation and hydrolysis of chitin from the exoskeleton of arthropod and insect and the cell wall of fungi. GOS is soluble in water, not cytotoxic, easy to be absorbed through intestinal tract, and mainly excreted from urine. COS and its derivatives have been known to have a variety of biological activities, including the anti-inflammatory, immunomodulatory, neuroprotective and antioxidant activities. This paper reviews the research progress in the preparation method, pharmacokinetics, bioactivity and the safety of GOS in recent years, hoping to provide a reference for related future researches.