Distribution of C- and O-glycosyl flavonoids, (3-hydroxy-3-methylglutaryl)glycosyl flavanones and furocoumarins in Citrus aurantium L. juice

The qualitative and quantitative flavonoid and furocoumarin composition of crude sour orange (Citrus aurantium L.) juice was determined via reverse-phase LC–DAD–ESI–MS–MS analysis. In a single course, a comprehensive chromatographic profile of 14 compounds (furocoumarins, C- and O-glycosyl flavonoids) was obtained. Seven flavonoids and a furocoumarin were identified for the first time in sour orange juice: three C-glucosides (lucenin-2, vicenin-2 and lucenin-2, 4′-methyl ether), two O-glycosides (rhoifolin 4′-glucoside and narirutin 4′-glucoside), two 3-hydroxy-3-methylglutaryl flavanone glycosides (melitidin and brutieridin) and a furocoumarin (epoxybergamottin). Furthermore, the antioxidant activity of sour orange juice was assessed by means of ABTS+ and DPPH radical scavenging assays.