AUTHOR=Geng Jie , Wang Guining , Guo Jiao , Han Xiao , Qu Yunhe , Zhou Yifa , Tai Guihua , Sun Lin , Cheng Hairong 

TITLE=Preparation and structural analysis of fucomannogalactan and β-1,6-glucan from Grifola frondosa mycelium

JOURNAL=Frontiers in Chemistry

VOLUME=11

YEAR=2023

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2023.1227288

DOI=10.3389/fchem.2023.1227288

ISSN=2296-2646

ABSTRACT=<p><bold>Introduction:</bold> Polysaccharides, key components present in <italic>Grifola frondosa</italic>, can be divided into those derived from fruiting bodies, mycelium, and fermentation broth based on their source. The structure of <italic>G. frondosa</italic> fruiting body-derived polysaccharides has been fully characterized. However, the structure of <italic>G. frondosa</italic> mycelium-derived polysaccharides remains to be elucidated.</p><p><bold>Methods:</bold> In this study, we obtained mycelia from <italic>G. frondosa</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.</p><p><bold>Results and discussion:</bold> Structural analysis showed that two neutral fractions (WGFP-N-a and AGFP-N-a<sub>1</sub>) have a common backbone composed of α-1,6-D-Me-Gal<italic>p</italic> and α-1,6-D-Gal<italic>p</italic> that were substituted at O-2 by 1,2-Man<italic>p</italic>, α-1,3-L-Fuc<italic>p</italic>, and α-T-D-Man<italic>p</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<italic>p</italic> and T-D-Glc<italic>p</italic> at the O-3 of Glc. Our results provide important structural information about <italic>G. frondosa</italic> mycelium-derived polysaccharides and provide the basis for their further development and application.</p>