Flavone-di- C-glycosides in citrus juices from Southern Italy

6,8-Di- C-glucopyranosylapigenin and 6,8-di- C-glucopyranosyldiosmetin were detected by HPLC–DAD–ESI–MS–MS in a variety of Southern Italian Citrus juices (orange, lemon, bergamot, citron, mandarin, clementine). In some juices, the amounts of C-glycosides detected were significant. 6,8-Di- C-glucopyranosylapigenin is characteristic of orange juice, while 6,8-di- C-glucopyranosyldiosmetin is the most important C-glycoside in lemon and citron juice. In bergamot juice the concentrations of 6,8-di- C-glucopyranosylapigenin and 6,8-di- C-glucopyranosyldiosmetin are similar. Clementine juice is distinctive as the amounts of both C-glycosides present are negligible.