Rapid Screening of Antioxidant Anthocyanins in Autochthonous Nero d'Avola Grape Clones by Pre-column DPPH Reaction Coupled to UHPLC-UV/Vis-IT-TOF: a Strategy to Combine Chemical data and Genetic Diversity.

Grape is a rich source of bioactive compounds;among them anthocyanins are associated to many healthyproperties, possessing a good antioxidant activity. In thiswork, we developed a fast and simple screening of antioxidantanthocyanins in six Sicilian Nero d’Avola autochthonousgrape clones. The method was based on the pre-column reac-tion with 2,2′-diphenyl-1-picrylhydrazyl radical followed bythe rapid separation by ultra high-pressure liquid chromatog-raphy coupled with ultraviolet and tandem mass spectrometrydetection. Peak areas of antioxidant anthocyanins significantlyreduced or even disappeared. The entire method took only45 min per sample, showing good retention time and peakarea repeatability with maximum CV% values≤0.86 and6.84, respectively. Samples rich in delphinidin derivativesshowed lowest IC50values, since those compounds possessthe highest scavenging ability. The developed setup was lesscomplex than online approaches and faster with respect toconventional high-performance liquid chromatographymethods, taking advantage of ultra high-performance condi-tions, coupled for the first time with pre-column 2,2′-diphenyl-1-picrylhydrazyl assay. The proposed strategy is avalid tool for a rapid screening of antioxidant anthocyaninsin grape samples, useful to correlate the genetic diversity withthe production of secondary metabolites as well to assess theiractivity in nutraceutical products rich in anthocyanins.