A New Galactoglucomannan from the Mycelium of the Medicinal Parasitic Fungus and Its Immunomodulatory Activity In Vitro and In Vivo.

A new galactoglucomannan (C-0-1) was purified from the medicinal parasitic fungus of using an anion-exchange column and gel permeation column. The results of high-performance liquid chromatography and high-performance gel permeation chromatography indicated that C-0-1 consists of galactose, glucose, and mannose in a ratio of 5:1:4 and has a molecular weight of 23.3 kDa. The combined structural elucidation analysis methods including partial acid hydrolysis, methylation analysis, and NMR experiments revealed that C-0-1 was a comb-like polysaccharide with a core structure including (1→2)-α-D-Man residues in the backbone and branches at -6 of the main chain. (1→4)-α-D-Glc, (1→2)-β-D-Gal, (1→2,6)-β-D-Gal, and terminal β-Gal were located at the side chains. An in vitro experiment using RAW 264.7 cells indicated that C-0-1 exhibits good immunomodulatory activity by enhancing inducible nitric oxide synthase secretion and the production of some major inflammatory cytokines. On inhibiting the cytokine production using anti-pattern recognition receptors antibodies, it was revealed that the activation of macrophages is mainly carried out by C-0-1 through the mannose receptor. Toll-like receptor 4 and Toll-like receptor 2 were also involved in this identification process. An in vivo experiment on immunosuppressive mice treated with cyclophosphamide indicated that C-0-1 improves the secretion of serum-related cytokines (IFN-γ, TNF-α, IL-2, IL-4, and IL-10) and affects the balance of T helper cells Th1/Th2. Given the structural and bioactivity similarity between and , we can conclude that could be used as an important medicinal fungus like .