Verbascoside

Methanol (MeOH) and acetonitrile (AcN) were purchased from Merck (Darmstadt, Germany) and phosphoric acid from Sigma-Aldrich (St. Louis, MO, USA). Standards of apigenin, apigenin-7-O-glucoside, catechin, hydroxytyrosol, luteolin, luteolin-7-O-glucoside, oleuropein, rutin, tyrosol, and verbascoside were purchased from Extrasynthese (Genay, France). Deionized water was obtained by Siemens UltraClear (Siemens AG, München, Germany).
Multi-element standard solution from Perkin Elmer (NexION Setup Solution, Waltham, MA, USA) was used. Argon used to form plasma for the inductively coupled plasma mass spectrometer (ICP-MS) analysis was of purity 6.0 (Messer, Austria). Acetylene was supplied by Messer (Messer Croatia Plin d.o.o., Zaprešić, Croatia).
Deionized water was obtained by Siemens UltraClear (Siemens AG, München, Germany).

HPLC-grade methanol, acetonitrile and formic acid were purchased from Sigma-Aldrich (St. Louis, MO, US). A Milli-Q system from Millipore (Bedford, MA, USA) was used for purifying demineralized water. The PVDF (polyvinylidene fluoride) syringe filters were also supplied by Millipore. The standards used were as follows: citric acid, isocitric acid, mannose, dulcitol, oleuropein, raffinose, stachyose, salidroside, sorbitol, tyrosol and 3,4-dihydroxyphenylglycol purchased from Sigma-Aldrich (St. Louis, MO, US); malic acid, fructose, glucose and sucrose purchased from Carlo Erba (Milan, Italy); succinic acid, galactinol, galactose and lactose purchased from Honeywell Fluka (Milan, Italy); quinic acid purchased from Roth (Karlsruhe, Germany); and hydroxytyrosol and verbascoside purchased from Extrasynthese (Genay Cedex, Lyon, France).

Methanol and n-hexane were purchased from Honeywell (Charlotte, North Carolina, USA), whereas ethanol was acquired from Scharlab (Barcelona, Spain). Double-deionized water was obtained using a Milli-Q system (Millipore, Bedford, MA, USA). Standards of trans-p-coumaric acid, hydroxytyrosol, tyrosol, maslinic acid, oleanolic acid and oleuropein were purchased from Sigma-Aldrich (St. Louis, MO, USA), and (+)-pinoresinol was acquired from PhytoLab (Vestenbergsgreuth, Germany). Apigenin and luteolin were purchased from LGC (Teddington, Middlesex, UK), and luteolin-7-O-glucoside, loganin and verbascoside were purchased from Extrasynthese (Lyon, France).

Folin-Ciocalteu’s phenol reagent, gallic acid, 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), 2,4,6-tri(2-pyridyl)-s-triazine (TPTZ), 6-hydroxy-2,5,7,8-tetramethyl-chroman-2-carboxylic acid (Trolox), β-carotene, linoleic acid, butylated hydroxyanisole (BHA), trifluoroacetic acid (TFA) and quercetin were obtained from Sigma-Aldrich (St. Louis, MO, USA). Hydroxytyrosol, verbascoside, oleuropein, luteolin 7-O-glucoside, luteolin 4’-O-glucoside and apigenin 7-O-glucoside were purchased from Extrasynthese S.A. (Genay, France) Solvents and other chemicals, if not otherwise specified, were acquired from Avantor Performance Materials (Gliwice, Poland).

Lipoid S75 (S75), a mixture of soybean phospholipids (~70% phosphatidylcholine, 9% phosphatidylethanolamine and 3% lysophosphatidylcholine), triglycerides and fatty acids, was purchased from AVG S.r.l. (Garbagnate Milanese, Milan, Italy), a local supplier for Lipoid GmbH (Ludwigshafen, Germany). Sodium hyaluronate was purchased from DSM Nutritional Products AG Branch Pentapharm (Aesch—BL/Switzerland). Tween 80, 2,2-diphenyl-1-picrylhydrazyl (DPPH), tetrazolium salt, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), ethanol, acetonitrile, methanol, phosphoric acid, and all the other solvents and reagents of analytical grade were purchased from Sigma-Aldrich (Milan, Italy). Standards of luteolin-7-O-glucoside, luteolin, apigenin, chlorogenic acid and verbascoside were purchased from Extrasynthese (Genay Cedex, France).
Reagents and plastics for cell culture were purchased from Life Technologies Europe (Monza, Italia). Ultrapure water (18 MΩ·cm) was obtained using a Milli-Q Advantage A10 System apparatus (Millipore, Milan, Italy).

Acetonitrile (AcN), methanol (MeOH), and Folin–Ciocalteu reagent were purchased from Merck (Darmstadt, Germany), phosphoric acid from Sigma-Aldrich (St. Louis, MO, USA), and acetic acid, hydrogen peroxide, and nitric acid from VWR International S.A.S. (Fontenay-sous-Bois, France). Apigenin, Apigenin-7-O-glucoside, catechin, hydroxytyrosol, luteolin, luteolin-7-O-glucoside, oleuropein, rutin, tyrosol, and verbascoside were purchased from Extrasynthese (Genay, France). All chemicals were of analytical grade purity and were used without further purification.
Deionised water was obtained using a Hydrolab 10 SP purification system (Hydrolab, Straszyn, Poland).