A review of Lycium barbarum polysaccharides: extraction, purification, structural characterization, and structure-activity relationships

Lycium barbarum , as a renowned medicinal and edible plant, has garnered significant attention for its wide-ranging health benefits. Lycium barbarum polysaccharides (LBPs) are the most crucial bioactive components in Lycium barbarum , possessing diverse nutritional functions and pharmacological activities. LBPs show broad prospects in the development of functional foods and pharmaceuticals, driving their widespread application across multiple fields. To gain a more systematic and comprehensive understanding of LBPs, this review discusses the latest research progress on their extraction, purification, separation, structural characterization, and structure-activity relationships. The article comparatively analyzes multiple extraction techniques, including hot water extraction (HWE), ionic liquid extraction (ILE), ultrasound-assisted extraction (UAE), microwave-assisted extraction (MAE), enzyme-assisted extraction (EAE), subcritical water-assisted extraction (SWE), high shear dispersing emulsification extraction (HSDEE), and synergistic extraction (UMAE: ultrasonic coupled with microwave assisted extraction; SUAE: subcritical coupled ultrasound-assisted extraction; EUAE: enzymatic coupled with ultrasonic assisted extraction) techniques utilizing multiple auxiliary methods. Concurrently, we also evaluated the economic feasibility and environmental impact of these methods in industrial applications. In terms of purification and separation, this review examines the efficiency of deproteinization, decolorization, and membrane separation methods, as well as advanced chromatographic techniques such as ion exchange chromatography (IEC), gel permeation chromatography (GPC), and high-speed countercurrent chromatography (HSCCC). Subsequently, the primary techniques used for structural characterization were analyzed, with a detailed introduction to the specific applications and advances in determining molecular weight (M w ), monosaccharide composition, glycosidic bond type and chain conformation using spectroscopic and mass spectrometric methods. On this basis, this review explores in depth the intrinsic relationship between the structural characteristics of LBPs and their biological activity, focusing on elucidating the effects of M w , monosaccharide composition, chain conformation, and chemical modification on biological activity. Furthermore, this review also offers a prospectus for future research directions. This review aims to lay a solid foundation for subsequent research and development of LBPs, and to provide valuable references for their production and application in functional foods and therapeutic drugs.