1 3 dicaffeoylquinic acid

Phospholipon90G (P90G; phosphatidylcholine content ≥ 94%) was purchased from Lipoid GmbH (Ludwigshafen, Germany). Propylene glycol (PG) were purchased from Galeno Srl (Comeana, Prato, Italy). LC-MS grade acetonitrile, formic acid, methanol, 85% w/w phosphoric acid, 2,2-diphenyl-1-picrylhydrazyl (DPPH), 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox), 2,4,6-tris(pyridin-2-yl)-1,3,5-triazine (TPTZ), 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), 2′,7′-dichlorofluorescein diacetate (DCFH-DA), dimethyl sulphoxide (DMSO), and all the other reagents, if not otherwise specified, were purchased from Sigma-Aldrich/Merck (Milan, Italy). Standards of 5-O-caffeoylquinic (chlorogenic acid), 1,3-dicaffeoylquinic acid (cynarin), 3,5-dicaffeoylquinic acid (isochlorogenic acid A), 3,4-dicaffeoylquinic acid (isochlorogenic acid B), 4,5-dicaffeoylquinic acid (isochlorogenic acid C), ferulic acid, apigenin, hispidulin, and luteolin were purchased from Extrasynthese (Genay, France) and TransMIT (Giessen, Germany). Ultrapure water (18 MΩ·cm) was obtained with a Milli-Q Advantage A10 System apparatus (Millipore, Milan, Italy).

Folin–Ciocalteu reagent, calcium chloride, citric acid, aluminum chloride, sodium nitrate, sodium hydroxide, and RPE methanol were purchased from Carlo Erba Reagents (Milan, Italy).
Chlorogenic acid, caffeic acid, p-coumaric acid, t-ferulic acid, 1,3-dicaffeoylquinic acid, luteolin, luteolin-7-O-glucoside, apigenin, and apigenin-7-O-glucoside were purchased from Extrasynthèse (Geney, France) and Sigma-Aldrich (St. Louis, MO, USA).
HPLC-grade solvents and water purified using a Milli-Q system (Millipore Corp., Billerica, MA, USA) were used in HPLC analysis.