Variation in the contents of four flavonoid glycosides in edible leaves during different harvesting periods and optimization of the extraction process.

Despite being recognized as a specialty food in four Chinese provinces with established safety standards, Kimura et Migo (Orchidaceae) leaf physicochemical indices overlook vital flavonoid glycoside components. Given the inconsistency in flavonoid quality under current standards, we devised a quantitative analysis targeting vicenin 2, vicenin 3, rutin, and isoviolanthin. Our analysis revealed significant seasonal variations, with harvests yielding the highest total content of these four flavonoid glycosides in February (1.