Flavonoid C-glycosides: from structure-activity relationships to food applications

Flavonoid C -glycosides are a class of plant‑derived natural products in which the sugar moiety is directly linked to the flavonoid aglycone via a C-C bond. Although the nutritional and health benefits of flavonoid C -glycosides are receiving increasing attention and popularity, the relationship between their structure and bioactivity remains unknown, which seriously hinders the development and utilization of these compounds in functional foods. This review builds upon previous studies by systematically integrating current knowledge on the structural diversity, health-related bioactivities, structure-activity relationships, and food-related applications of flavonoid C -glycosides. Particular emphasis is focused on the structural determinants that modulate their bioavailability and metabolic stability, including hydroxylation patterns, glycosylation sites, and the C-C glycosidic bond. This review comprehensively summarizes the key bioactivities of these compounds in relation to human health promotion and food functionality, and further explores their emerging applications in functional food development. Special attention is given to AI‑driven strategies for predicting dietary sources, assessing bioactivity, simulating metabolic pathways, and optimizing formulation design. This review consolidates fragmented knowledge into a coherent framework, with the aim of guiding the rational design and practical translation of flavonoid C -glycosides for functional food applications.