Fungal polysaccharide similar with host Dendrobium officinale polysaccharide: Preparation, structure characteristics and biological activities.

Based on the concept of endophytic fungus, if endophytic fungus can produce the same or similar product as the host plant, which will get rid of the restrictions of farmland, seasonal and pest, the active product could be sustainably obtained. In this study, an endophytic fungus polysaccharide FP showing the similar structure with the host Dendrobium officinale polysaccharide (DOP) was sustainably and cost-effectively obtained under preferred reaction conditions with different C/N ratio. The FP with high yield up to 2.77 ± 0.51 g/L showed same monosaccharide composition with DOP as well as some host-plant-associated polysaccharides in published literatures. The main chain of FP was composed by →3,6)-β-L-Man-(1→, α-D-Glc-(1→, →4)-α-D-Glc-(1→, →3,6)-β-D-Gal-(1→, and →6)-β-D-Gal-(1→, while the side chain was α-D-Glc-(1→. Meanwhile, FP was confirmed as a safe polysaccharide with good antioxidant, antiglycation and immunomodulatory activities. Furthermore, TLR2 and TLR4 were confirmed as the membrane receptors of FP on RAW264.7 cells.