Flavonoid profile and radical-scavenging activity of Mediterranean sweet lemon (Citrus limetta Risso) juice

The flavonoid composition of crude Citrus limetta Risso (limetta, Mediterranean sweet lemon) juice was elucidated by means of reverse-phase HPLC–DAD–ESI-MS/MS analysis. In a single course, eight compounds (C- and O-glycosyl flavonoids) were identified, six of which were found for the first time in limetta juice: four C-glucosyl flavones, namely vicenin-2, lucenin-2 4′-methyl ether, orientin 4′-methyl ether and scoparin; the O-glycosyl flavone, rhoifolin; and the O-glycosyl flavanone, eriocitrin. In addition, ABTS+ and DPPH radical quenching and FRAP assays demonstrate that limetta juice possesses remarkable antioxidant activity.