Petunidin 3 glucoside chloride

All chemicals and reagents used and purchased were of analytical quality. Adenosine monophosphate (AMP) was purchased from Alexis Biochemicals (Lörrach, Germany); barium hydroxide octahydrate (Ba(OH)₂·8H₂O), caffeine, cyclic adenosine monophosphate (cAMP), phosphodiesterase (PDE) 3B (recombinant, EC 3.1.4.17), gallic acid, and ascorbic acid from Sigma Aldrich (St. Louis, MO, USA); [2,8-³H]-3′5′-cyclic adenosine monophosphate ammonium salt, 9.25 MBq/mL, from Hartmann Analytic (Braunschweig, Germany). Tris-(hydroxymethyl)-aminomethane (TRIS), and hydrochloric acid were obtained from Carl Roth (Karlsruhe, Germany). The Folin–Ciocalteu reagent, magnesium chloride hexahydrate (MgCl₂·6H₂O), and zinc sulphate heptahydrate (ZnSO₄·7H₂O) were ordered from Merck (Darmstadt, Germany), and dimethyl sulfoxide (DMSO) was obtained from VWR Int. S.A.S. (Darmstadt, Germany). Peonidin-3-glucoside chloride, cyanidin-3-arabinoside chloride, petunidin-3-glucoside chloride, cyanidin-3-glucoside chloride, cyanidin-3-galactoside chloride, malvidin-3-glucoside chloride, cyanidin-3-rutinoside chloride, cyanidin-3,5-diglucoside chloride, and cyanidin chloride were supplied by PhytoLab (Vestenbergsgreuth, Germany).

The 36 analytical standards were obtained from Sigma-Aldrich (Milan, Italy), except for delphinidin-3,5-diglucoside chloride, petunidin-3-glucoside chloride, cyanidin-3-glucoside chloride, delphinidin-3-galactoside chloride, malvidin-3-galactoside chloride, kaempferol-3-glucoside, and quercetin-3-glucoside, which were supplied by PhytoLab (Vestenbergsgreuth, Germany). Single stock solutions of each component were made by dissolving pure analytes in methanol and storing them at 4 °C until analysis, except for anthocyanins, which were maintained at −18 °C until analysis. Working solutions of the standards at different concentrations were made every day by dilution of the stock solutions with methanol. All solvents used for chromatographic purposes were HPLC grade. The 99% Formic acid was supplied by Merck (Darmstadt, Germany). HPLC-grade methanol was purchased from Sigma-Aldrich (Milano, Italy). Deionized water (>18 MΩ cm resistivity) was further purified using a Milli-Q SP Reagent Water System (Millipore, Bedford, MA, USA). All solutions and solvents were filtered by a 0.2-μm polyamide filter purchased from Sartorius Stedim (Goettingen, Germany). All samples were filtered before HPLC analysis, by using Phenomenex 0.2-μm syringeless filters.