New Polysaccharides from <i>Hygrophorus olivaceoalbus</i> (HO-P) and <i>Agrocybe aegerita</i> (AA-P) and their Biological Activities

Background Fungal polysaccharides are an essential active polymer compound in human cells. A clear understanding of the structure of polysaccharides is the foundation for conducting research and utilization of polysaccharides. Objectives To explore the structure and immunomodulatory activities of polysaccharides from Hygrophorus olivaceoalbus and Agrocybe aegerita. Materials and Methods High-performance liquid chromatography, high-performance gel-permeation chromatography, nuclear magnetic resonance, and gas chromatography–mass spectrometry analysis were utilized to analyze the structure of Hygrophorus olivaceoalbus polysaccharide (HO-P) and Agrocybe aegerita polysaccharide (AA-P). The immunomodulatory activities of these polysaccharides were also studied. Results The HO-P consisted of (1↓6)-Galp, (1↓4)-Glup, (↓1)-Glup, and (1↓4,6)-D-Manp with the ratio of mannose, galactose, and glucose being 1:1:2. The AA-P was consisted of (1↓4,6)-Glup, (1↓4)-Arap, and (1↓6)-Galp with the ratio of galactose, glucose, and arabinose being 3:2:1. AA-P and HO-P could both mainly by reducing G 0 /G 1 phase, which leads to the significant proliferation of B cells and RAW264.7 cells, respectively. At the same time, AA-P and HO-P could significantly stimulate the necrosis factor-α secretion of T cells, IgA, IgD, IgE, IgG, and IgM secretion of B cells and tumor necrosis factor-α secretion of RAW264.7 cells, but neither of them could stimulate interleukin-1↓ secretion of RAW264.7 cells. Conclusion Due to its better branching degree, AA-P is more conducive to forming a triple-helix, three-dimensional configuration, as well as better solubility and smaller molecular weight, thus exhibiting higher biological immune activity against immune cells than HO-P.