Recent advances in polysaccharides: Mycelial fermentation, isolation, structure, and bioactivities: A review.

, the Chinese caterpillar fungus, is a unique and precious medicinal fungus in traditional Chinese medicine which has been used as a prestigious tonic and therapeutic herb in China for centuries. Polysaccharides are bioactive constituents of , exhibiting several activities such as immunomodulation, antitumour, antioxidant and hypoglycaemic. As natural fruiting body-caterpillar complexes are very rare and expensive, the polysaccharides documented over the last 15-20 years from this fungal species were mostly extracted from cultivated fungal mycelia (intracellular polysaccharides) or from mycelial fermentation broth (exopolysaccharides). Extraction and purification of the polysaccharides is a tedious process involving numerous steps of liquid and solid phase separations. Nevertheless, a large number of polysaccharide structures have been purified and elucidated. However, relationships between the structures and activities of these polysaccharides are not well established. This review provides a comprehensive summary of the most recent developments in various aspects (i.e., production, extraction, structure, and bioactivity) of the intracellular and exopolysaccharides from mycelial fermentation of . fungi. The contents and data will serve as useful references for further investigation, production and application of these polysaccharides in functional foods and therapeutic agents.