Methanol lichrosolv

Ammonium acetate (NH₄OAc, ≥99.99%), ammonium hydroxide (ACS reagent) and Tween 20 (BioXtra) were from Sigma Aldrich (Steinheim, Germany). Chloroform (Spectronorm) was obtained from VWR (Roncello, Italy), Methanol (LiChrosolv) from Merck (Darmstadt, Germany). Atto633-COOH was purchased from Atto Tec (Siegen, Germany). Nitrogen gas was from Messer (Gumpoldskirchen, Austria). The lipids 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (16:0 PC, DPPC), 1,2-dioctadecanoyl-sn-glycero-3-phosphoethanolamine (18:0 PE, DSPE), 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000] (ammonium salt) (18:0 PEG2000 PE, DSPE-PEG2000) and cholesterol (Chol) were from Avanti Polar Lipids (Alabaster, AL, USA obtained via Instruchemie, Delfzyl, The Netherlands). Water was of Millipore grade (18.2 MΩ cm resistivity at 25 °C). NH₄OAc (40 mmol L^–1, pH 8.4) filtered through a 0.2 μm pore size syringe filter (surfactant free cellulose acetate membrane from Sartorius, Göttingen, Germany) was used as aqueous electrolyte.

White medium [75 ], sucrose, casein hydrolysate and agar (plant tissue micropropagation culture grade) were from PhytoTechnology Laboratories (Lenexa, KS, USA). LiChrosolv^® Methanol was supplied by Merck (Darmstadt, Germany). Formic acid was purchased from Baker (New Jersey, USA). Ultrapure water was generated with a Barnstead Thermo Scientific™ (Waltham, MA, USA). Quercetin-3-rhamnoside (Q-3-O-Rh) was from Extrasynthese (Lyon, France); catechin (C), quercetin-3-O-glucoside (Q-3-O-G), quercetin-3-O-xyloside (Q-3-O-X), quercetin-3-O-arabinofuranoside (Q-3-O-AF), quercetin-3-O-arabinopyranoside (Q-3-OAP), and chlorogenic acid (CA) were from Sigma (St. Louis, MO, USA). The other chemicals, standards, and solvents were purchased from Sigma-Aldrich (Saint Louis, MO, USA).

Salicylic acid (SA), 2,4-dihydroxybenzoic acid (2,4-DHBA) and 3,4-dihydroxybenzoic acid (3,4-DHBA) standards were purchased from Fluka (Budapest, Hungary). 2,3-Dihydroxybenzoic acid (2,3-DHBA) and 2,5-dihydroxybenzoic acid (2,5-DHBA) standards and acetic acid were obtained from Sigma-Aldrich (Budapest, Hungary). LiChrosolv methanol was produced by Merck KGaA (Darmstadt, Germany). Analytical reagent grade diethyl ether and perchloric acid, furthermore puriss grade sodium dihydrogen phosphate (NaH₂PO₄, anhydrous) and disodium hydrogen phosphate (Na₂HPO₄ x 2 H₂O) were purchased from Spektrum-3D (Debrecen, Hungary). Analytical reagent grade disodium salt of ethylenediaminetetraacetic acid (Na₂EDTA), iron(II) ammonium sulphate (Fe(NH₄)₂(SO₄)₂ x 6 H₂O) and sodium sulphate (Na₂SO₄, anhydrous) were obtained from Reanal (Budapest, Hungary). Analytical reagent grade ascorbic acid was purchased from Molar Chemicals (Budapest, Hungary). Distilled water was purified in the Institute of Pharmaceutical Chemistry, University of Pécs. Mobile phases used for HPLC were degassed in ultrasonic bath (Realsonic cleaner) and filtered through ROBU-GLASS filter before use.

Water (HPLC gradient grade) was purchased from J.T. Baker (Deventer, The Netherlands). Pestinorm® Supra Trace ethyl acetate was purchased from VWR Chemicals (Leuven, Belgium). LiChrosolv® methanol (hypergrade for LC-MS), potassium carbonate (pro analysi grade) and calcium carbonate (pro analysi grade) were obtained from Merck KGaA (Darmstadt, Germany). Sodium sulphite (puriss p.a., ACS grade) and hydrogen peroxide solution (≥ 30%, trace analysis grade) were obtained from Sigma-Aldrich (St. Louis, USA). Rotipuran® formic acid (≥98%, p.a., ACS grade), Rotipuran® hydrochloric acid (37%, p.a., ACS, ISO grade) and Pufferan® TRIS hydrochloride (≥ 99%, p.a. grade) were purchased from Carl Roth GmbH + Co. KG (Karlsruhe, Germany). Proteinase K was purchased from Qiagen GmbH (Hilden, Germany).