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

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

doi:10.3389/fchem.2023.1227288

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

Front Chem. 2023 Aug 7:11:1227288. doi: 10.3389/fchem.2023.1227288. eCollection 2023.

Authors

Jie Geng¹, Guining Wang¹, Jiao Guo¹, Xiao Han¹, Yunhe Qu², Yifa Zhou¹, Guihua Tai¹, Lin Sun¹, Hairong Cheng¹

Affiliations

¹ Jilin Province Key Laboratory on Chemistry and Biology of Changbai Mountain Natural Drugs, Glycoconjugate Engineering Research Center of the Ministry of Education, School of Life Sciences, Northeast Normal University, Changchun, China.
² Central Laboratory, Changchun Normal University, Changchun, China.

Abstract

Introduction: Polysaccharides, key components present in Grifola frondosa, can be divided into those derived from fruiting bodies, mycelium, and fermentation broth based on their source. The structure of G. frondosa fruiting body-derived polysaccharides has been fully characterized. However, the structure of G. frondosa mycelium-derived polysaccharides remains to be elucidated. Methods: In this study, we obtained mycelia from G. frondosa 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. Results and discussion: Structural analysis showed that two neutral fractions (WGFP-N-a and AGFP-N-a₁) have a common backbone composed of α-1,6-D-Me-Galp and α-1,6-D-Galp that were substituted at O-2 by 1,2-Manp, α-1,3-L-Fucp, and α-T-D-Manp 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-Glcp and T-D-Glcp at the O-3 of Glc. Our results provide important structural information about G. frondosa mycelium-derived polysaccharides and provide the basis for their further development and application.

Keywords: Grifola frondosa; fucomannogalactan; glucan; mycelium; structure analysis.

Grants and funding

This work was supported by the National Natural Science Foundation of China (no. 22007011), Jilin Provincial Science and Technology Department Program (no. YDZJ202101ZYTS088), and Jilin Province Development and Reform Commission (no. 2022C042-8).