Research Progress on Extraction, Purification and Biological Activities of Nostoc flagelliforme Polysaccharides

Nostoc flagelliforme is a kind of terrestrial Nostoc, and can usually be used as food and medicine. It includes sugars, various amino acids and trace elements, vitamins, echinone, phycocyanophyll, phycocyanin, allophycocyanin and some other functional ingredients. Nostoc flagelliforme cells can synthesize a gelatinous substance, and its main functional ingredient is Nostoc flagelliforme polysaccharide. At present, a number of studies have shown that Nostoc flagelliforme polysaccharides have various bioactivities, such as antioxidant, antiviral, anti-tumor, anti-microbial, anti-inflammatory and immune regulation. Therefore, Nostoc flagelliforme polysaccharides have great potential in the fields of food and medicine. This paper mainly reviews the methods of extraction, separation, purification and the structural characteristics of Nostoc flagelliforme polysaccharides, and also summarizes the research progress on biosynthesis and bioactivities of Nostoc flagelliforme polysaccharides, expecting to provide theoretical basis for further researches and development of Nostoc flagelliforme polysaccharides.