Description:
<jats:p><jats:bold>Introduction:</jats:bold> Polysaccharides, key components present in <jats:italic>Grifola frondosa</jats:italic>, can be divided into those derived from fruiting bodies, mycelium, and fermentation broth based on their source. The structure of <jats:italic>G. frondosa</jats:italic> fruiting body-derived polysaccharides has been fully characterized. However, the structure of <jats:italic>G. frondosa</jats:italic> mycelium-derived polysaccharides remains to be elucidated.</jats:p><jats:p><jats:bold>Methods:</jats:bold> In this study, we obtained mycelia from <jats:italic>G. frondosa</jats:italic> by liquid fermentation and extracted them with water and alkaline solution. Then, the mycelia were isolated and purified to obtain homogeneity and systematically characterized by methylation and FT infrared (FT-IR) and nuclear magnetic resonance (NMR) spectroscopy.</jats:p><jats:p><jats:bold>Results and discussion:</jats:bold> Structural analysis showed that two neutral fractions (WGFP-N-a and AGFP-N-a<jats:sub>1</jats:sub>) have a common backbone composed of α-1,6-D-Me-Gal<jats:italic>p</jats:italic> and α-1,6-D-Gal<jats:italic>p</jats:italic> that were substituted at O-2 by 1,2-Man<jats:italic>p</jats:italic>, α-1,3-L-Fuc<jats:italic>p</jats:italic>, and α-T-D-Man<jats:italic>p</jats:italic> and thus are identified as fucomannogalactans. WGFP-A-a, AGFP-A-b, and AGFP-A-c are β-1,6-glucans with different molecular weights and are branched with β-1,3-D-Glc<jats:italic>p</jats:italic> and T-D-Glc<jats:italic>p</jats:italic> at the O-3 of Glc. Our results provide important structural information about <jats:italic>G. frondosa</jats:italic> mycelium-derived polysaccharides and provide the basis for their further development and application.</jats:p>