The mis-identification of the major antioxidant flavonoids in young barley (Hordeum vulgare) leaves

Several papers have appeared in the literature since 1992 which refer to a major "isoflavonoid" antioxidant in young green barley leaves (Hordeum vulgare) as 2'-O-glucosylisovitexin. In the present paper the original NMR data supporting this structural assignment are examined and found to have been misinterpreted. HPLC and NMR data are used to prove that the major flavonoid antioxidants in young green barley leaves are in fact the flavone-C-glycosides, saponarin and lutonarin.