bioflavonoid

:  flavonoid; specifically :  any of various flavonoids (as hesperidin and quercetin) that are biologically active in the human body Oranges, lemons, limes, grapefruit—all citrus fruits are concentrated sources of the antioxidant vitamin C. They also contain other compounds, folate and bioflavonoids, which have an excellent research track record for helping ward off cancer …—David Feder, Better Homes and Gardens, June 1998 A tea made from buckwheat, high in the bioflavonoid rutin, has been shown to alleviate symptoms.—Anna Soref, Yoga Journal, January/February 2000