Punicalin

The powdered pomegranate extract (Dermogranate^®) employed in this study was provided by Medinutrex (Catania, Italy). Briefly, the extract was prepared from dried and grinded pomegranate fruits mixed with hydroalcoholic solutions (food grade) and then filtered. The filtrate was concentrated and then spray-dryed to obtain the standardized extract. The Dermogranate^® extract had the following chemical composition: total polyphenols (16%), punicalagins (8%), ellagic acid, and derivatives (8%).
Folin–Ciocalteu reagent (FCR), sodium carbonate (Na₂CO₃), gallic acid, punicalin (mixture of anomers), punicalagin, and ellagic acid were purchased from Sigma-Aldrich (Milan, Italy). Granatin B was purchased from LGC Standards (London, United Kingdom). HPLC–MS grade solvents (Merck KgaA, Darmstadt,Germany) were used for chromatography and all other reagents were of analytical grade.

The chemicals 1,1-Diphenyl-2-picrylhydrazyl (DPPH), 2,4,6-Tris(2-pyridyl)-s-triazine (TPTZ), (±)6-Hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid (TROLOX), 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), diammonium salt (98%TLC), ABTS, gallic acid, sodium carbonate monohydrate ACS reagents, and ethanol (final ethanol grade) were purchased from Sigma-Aldrich (Steinheim, Germany); Manganese (IV) oxidise activated (˃90%), and Folin–Ciocalteu’s phenol reagents were purchased from Fluka (Buchs, Switzerland). Analytical grade solvents and reagents were used for all of the work. Ellagic acid, gallic acid, punicalagin A and B, punicalin, cyanidin 3-glucoside, cyanidin 3,5-diglucoside, pelargonidin 3,5-diglucoside, and pelargonidin 3-glucoside were obtained from Sigma-Aldrich (Stenheim, Germany). Formic acid and acetonitrile for LC/MS were purchased from Carlo Erba Reagents (Cornaredo, MI, Italy). Sigma Aldrich provided all the other chemicals (Steinheim, Germany). The ultrapure water was produced from the Millipore system (Millipore Sigma, Darmstadt, Germany), and filtered with a 0.20 μm Sartolon polyamide filter (Sartorius Stedim Biotech, Göttingen, Germany).