E ε viniferin

Gallic, 4-hydroxybenzoic, and ellagic acids, catechin, epicatechin, (E)-resveratrol, (E)-ε-viniferin, (E)-piceatannol, eriodictyol, taxifolin, quercetin, quercetin-3-O-glucoside, and quercetin-3-O-glucuronide were purchased from Sigma-Aldrich (St. Louis, MO, USA). Gallic acid and kaempferol-3-O-glucoside were acquired from Extrasynthèse (Genay, Auvergne-Rhône-Alpes, France). Isohopeaphenol and hopeaphenol were kindly given by the research group of Prof. Dr. Peter Winterhalter (Institute of Food Chemistry, Technical University Braunschweig, Lower Saxony, Germany). Light exposure was avoided when manipulating the standards.
HPLC-grade acetonitrile, formic acid, ethanol, and water were purchased from Merck (Darmstadt, Hesse, Germany). Ultrapure water was generated by a Milli-Q water purification system Millipore (Bedford, Massachusetts, USA). Potable ethanol (96%) from molasses employed for pilot-plant scale extraction was purchased from Oxiquim S.A. (Coronel, Concepción, Chile).
Hydroxypropyl beta-cyclodextrin (HP-β-CD, Kleptose^®, HP oral grade) was purchased from Roquette Frères (Lestrem, Lillers, France). Maltodextrin (MD) (dextrose equivalent 16.5–19.5) was obtained from Merck KGaA, (Darmstadt, Hesse, Germany).

Acetonitrile, formic acid, water, and ethanol were purchased from Merck (Darmstadt, Germany). All solvents were of HPLC grade. Ultrapure water was obtained from a Milli-Q water purification system (Millipore, Bedford, MA, USA).
Gallic, ellagic, and 4-hydroxybenzoic acid, (+)-catechin, (−)-epicatechin, (E)-resveratrol, (E)-piceatannol, quercetin-O-glucoside, and (E)-ε-viniferin were purchased from Sigma-Aldrich (St. Louis, MO, USA). Epicatechin gallate was acquired from Extrasynthèse (Genay, France). All standards were handled without exposure to light.