Advances in extraction, structural characterization, and bioactivities of Armillaria mellea polysaccharides: insights into structure-activity relationships and future applications.

Armillaria mellea is an edible and medicinal fungus rich in bioactive polysaccharides (AMPs), which have attracted increasing attention due to their diverse pharmacological activities and potential applications in functional foods and pharmaceuticals. This review aims to systematically summarize recent advances in the extraction, purification, structural characterization, and biological activities of AMPs, with a particular focus on their structure-activity relationships. Relevant literature published between 2005 and 2025 was retrieved from databases including Web of Science and CNKI. Studies were selected based on their relevance to AMPs. Data extraction focused on extraction techniques, structural features (molecular weight, monosaccharide composition, glycosidic linkages), and reported biological activities. Bibliometric analysis using CiteSpace was conducted to identify research trends and hotspots. Various extraction methods, including hot water, ultrasound-assisted, and enzyme-assisted techniques, significantly influence yield and structural integrity of AMPs. Structural analyses reveal that AMPs are heterogeneous polysaccharides with diverse molecular weights and monosaccharide compositions. These structural features are closely associated with multiple bioactivities, including antioxidant, immunomodulatory, hypoglycemic, and anti-inflammatory effects. Emerging evidence highlights the importance of molecular weight, branching degree, and glycosidic linkages in determining biological functions. AMPs exhibit significant potential as bioactive carbohydrate polymers. However, systematic elucidation of their structure-activity relationships remains limited. Future research should focus on integrating advanced structural characterization with mechanistic studies to support their development in functional and pharmaceutical applications.