C- and O-glycosyl flavonoids in Sanguinello and Tarocco blood orange (Citrus sinensis (L.) Osbeck) juice: Identification and influence on antioxidant properties and acetylcholinesterase activity.

Sanguinello and Tarocco are the blood orange (Citrus sinensis (L.) Osbeck) cultivars most diffused worldwide. Reversed phase liquid chromatography coupled with MS-MS analysis showed that these two varieties have a similar chromatographic pattern, characterised by the presence of C- and O-glycosyl flavonoids. Of the two, Sanguinello was found to be far richer in flavonoids than Tarocco. In the juices, twelve individual components were identified for the first time, namely, four C-glycosyl flavones (lucenin-2, vicenin-2, stellarin-2, lucenin-2 4'-methyl ether and scoparin), three flavonol derivatives (quercetin-3-O-(2-rhamnosyl)-rutinoside, quercetin-3-O-hexoside, quercetin 3-hydroxy-3-methylglutaryl-glycoside), an O-triglycosyl flavanone (narirutin 4'-O-glucoside) and a flavone O-glycosides (chrysoeriol 7-O-neoesperidoside). Moreover, the influence of the identified C- and O-glycosyl flavonoids on the antioxidant and acetylcholinesterase activity of these juices has been evaluated.