*3.1. Chemicals and Reagents*

LC–MS-grade water (H2O), acetonitrile (ACN), formic acid, methanol, and DMSO were purchased from Merck Life Science (Merck KGaA, Darmstadt, Germany). Taxifolin, rutin, 4-caffeoylquinic acid, ishorhamnetin, quercetin, and kaempferol-3-glucoside were also obtained from Merck Life Science (Merck KGaA, Darmstadt, Germany). Unless indicated otherwise, all chemicals were purchased from Sigma-Aldrich (Milan, Italy).
