Review of polysaccharides from Citrus medica L. var. sarcodactylis. (Fingered citron): Their extraction, purification, structural characteristics, bioactivity and potential applications

Citrus medica L. var. sarcodactylis. (Fingered citron), commonly known as Buddha's hand, is a revered member of the Citrus genus belonging to the Rutaceae family with a long history in China. Fingered citron is known for its multifaceted utility as traditional herbal medicine, functional food and ornamental plant. Fingered citron polysaccharides (FCPs) are the key bioactive components of Citrus medica L. var. sarcodactylis, garnering global attention for their potential medicinal and culinary benefits. Various extraction methods like solvent extraction, ultrasound or microwave-assisted extraction have been used to obtain FCPs. Nonetheless, the structural characteristics of FCPs remain incompletely understood, necessitating further research and elucidation of the potential structure-activity relationship via the combined use of various advanced analytical techniques. Furthermore, FCPs exhibit diverse bioactivities, such as antioxidant activity, immunomodulatory effect, antiinflammatory effect and gut microbiota regulatory activity, among others, positioning them as viable candidates for the therapeutic and health-promoting applications. Consequently, this review seeks to offer a comprehensive overview of FCPs, covering their extraction, purification, structural features, biological activities, and potential applications, underscoring the significant promise of FCPs as valuable natural compounds with multiple bioactive properties, advocating for their expanded utilization and integration into industry and therapeutics.