Selenium-Polysaccharides: Structural Characterization, Biological Activities, and Emerging Applications

Selenium-polysaccharides (SePs) are an emerging class of bioactive compounds formed by incorporating inorganic Se into polysaccharides, exhibiting enhanced biological activity compared to inorganic Se or isolated polysaccharides. The extraction of SePs from Se-enriched sources and the selenylation of polysaccharides are crucial for improving their biological activities, leading to structural variations that contribute to diverse biological effects. Structural variations in SePs, influenced by the incorporation of Se at specific positions or the formation of seleno-groups, play a key role in their biological effects. SePs have demonstrated antioxidant, anti-cancer, immune-regulating, anti-inflammatory, and other health benefits, making them promising candidates for nutraceutical applications. However, several areas remain underexplored in existing reviews, such as the dynamics of Se and its biosynthetic pathways in plants, as well as the structure-activity relationships and emerging applications of SePs. This study aims to investigate these biosynthetic pathways, structure-activity relationships, and the potential therapeutic and industrial applications of SePs. It highlights their potential in the food and health sectors, while also emphasizing the need for further research in these areas.