Quali-quantitative analysis of the phenolic fraction of the flowers of Corylus avellana, source of the Italian PGI product “Nocciola di Giffoni”: Isolation of antioxidant diarylheptanoids

Three diarylheptanoids named giffonins Q-S (10-12) along with nine known compounds were isolated from the MeOH extract of the flowers ofCorylusavellana, cultivar 'Tonda di Giffoni'. The quantitative determination of the main compounds and the evaluation of their inhibitory effects on human plasma lipid peroxidation induced by H2O2and H2O2/Fe2+were carried out.