Polyglucosides

Polyglucosides are polymers composed entirely of glucose units linked by glycosidic bonds. They form a broad family of carbohydrates with diverse architectures, ranging from linear to highly branched chains and from beta- to alpha-glycosidic linkages, yielding materials with different physical and biological properties.

Natural polyglucosides include cellulose (β-1,4 linked glucose forming rigid fibers), starch components such as amylose (primarily α-1,4) and amylopectin (α-1,4 with α-1,6 branches), and glycogen (highly branched α-1,4/1,6). Microbial and fungal glucans, dextrans, and pullulan expand the family. The diversity of linkages and branching patterns underpins a wide range of functions in nature, from structural polymers to energy storage.

Linkage type and branching govern solubility, crystallinity, and digestibility. Beta-linked cellulose is resistant to human enzymes, contributing to plant cell-wall strength, while alpha-linked glucans are more readily digested and often more soluble. Molecular weight and chain architecture influence viscosity, gel formation, and material properties.

Biosynthesis occurs via glycosyltransferases that assemble glucose units from activated donors, with specific enzymes determining the linkage pattern and branching. Degradative enzymes include cellulases, amylases, and glucanases. Humans can digest starch but not cellulose, whereas many microorganisms metabolize a range of glucans.

Applications and relevance include use as thickeners and stabilizers in foods, biodegradable packaging and films, pharmaceutical excipients, and components in adhesives and coatings. Ongoing research aims to tailor polyglucosides with defined linkages and architectures for materials science, biotechnology, and sustainable product development.