Ultrasound-Assisted Extraction of Polysaccharides from Lyophyllum decastes: Structural Analysis and Bioactivity Assessment

This study employed ultrasound-assisted extraction (UAE) to isolate polysaccharides from Lyophyllum decastes, which were subsequently fractionated into two components, LDP-A1 and LDP-B1, using DEAE cellulose-52 and Sephacryl S-500. The structural characteristics of the polysaccharides were preliminarily analyzed using high-performance liquid chromatography (HPLC), Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), and Congo red staining. The results indicate significant differences between LDP-A1 and LDP-B1 in terms of molecular weight, monosaccharide composition, and structural features. LDP-A1 (2.27 × 106 Da) exhibits a significantly higher molecular weight compared to LDP-B1 (9.80 × 105 Da), with distinct differences in monosaccharide types and content. Both polysaccharides contain β-glycosidic bonds. LDP-B1 adopts a sheet-like structure with an amorphous internal arrangement and a triple-helix configuration, whereas LDP-A1 is rod-shaped, with a crystalline internal structure, and lacks the triple-helix configuration. In terms of biological activity, both polysaccharides exhibit certain activities, but LDP-B1 shows significantly stronger activity in antioxidant, hypoglycemic, anti-inflammatory, and anticancer effects. In summary, LDPs exhibit significant biological activity, especially outstanding performance in antioxidant, hypoglycemic, anti-inflammatory, and anticancer effects, proving their potential for development in functional foods and pharmaceuticals. Their unique structural characteristics and diverse biological activities provide a solid theoretical foundation for further exploration of LDPs in health promotion and disease prevention, opening up new research directions and application prospects.