Penta galloyl glucose

Full extracts (60% ethanol) of Hamamelis virginiana L. leaf or bark, as well as ultrafiltration (UF) concentrates and filtrates were prepared as previously described [47] (link). For bark extract fractionation into UF-concentrate and filtrate, a Pro Flux M12 Tangential Flow Filtration System (Millipore) with Pellicon 2 Ultrafiltration Cassettes (C Screen, Millipore) was used. All extracts and UF-fractions were prepared at Dr. Willmar Schwabe GmbH & Co. KG, Karlsruhe and provided as dry powders. Concentrations indicated designate dry extract weight per volume of solvent. Gallic acid monohydrate (“gallic acid”), penta-O-galloyl-β-D-glucose (“pentagalloylglucose”), hamamelitannin, tannic acid and (−)-epigallocatechin gallate (EGCG) were purchased from Sigma-Aldrich. The buffer capacity of the cell culture medium fully neutralized the acidity of compounds added to in vitro experiments.

Gallic acid, catechin, epicatechin, epicatechin gallate, ellagic acid, quercetin, caffeic acid, penta-galloyl-glucose (PGG), and methyl gallate were purchased from Sigma-Aldrich (CA, USA). Folin-Ciocalteu reagent, ethanol, EDTA, and Tris-HCl were purchased from POCH (Gliwice, POLAND). Acetonitrile, methanol, and formic acid were purchased from Bujno Chemicals (Rathburn, Walkerburn, Scotland). PHAGOBURST was purchased from GLYCOTOPE Pharma (Heidelberg, Germany). RIPA buffer was purchased from Pierce (Rockford, IL, USA). Catalase Assay Kit and Glutathione Peroxidase Cellular Activity Assay Kit were purchased from Sigma-Aldrich (USA). SOD determination kit was purchased from FLUKA (Switzerland).