glukan

Glukan, or glucan, is a polysaccharide composed of glucose units linked by glycosidic bonds. It represents a broad class of glucose polymers found in plants, fungi, bacteria and yeasts. Glucans are commonly classified by the type of glycosidic linkages and by branching patterns. Alpha-glucans include starch and glycogen, which function as energy storage in plants and animals, respectively. Beta-glucans encompass beta-1,3- and beta-1,6-linked polymers, which occur in fungal cell walls, some yeasts and certain algae; cellulose is often considered a separate beta-glucan with beta-1,4 linkages.

In fungi, beta-glucans contribute to cell wall integrity and are a target of immune recognition. The biological and practical roles of glucans vary: beta-glucans are studied for immune-modulating effects and are used as dietary fiber with potential prebiotic benefits; alpha-glucans serve primarily as energy reserves. Industrially, glucans are used as thickening and stabilizing agents, dietary ingredients and excipients in foods and pharmaceuticals.

Notable glucans include curdlan (beta-1,3-glucan), laminarin (beta-1,3/1,6-glucan) from brown algae, and paramylon (beta-1,3-glucan) from Euglena. The properties of glucans depend on linkage types, branching, and molecular weight, which influence solubility and biological activity. Safety and regulatory status depend on the source and processing, but glucans from many fungi and yeasts are commonly used as food ingredients and supplements.

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