Pentagalloylglucose, or more specifically 1,2,3,4,6-penta-O-galloyl-β-D-glucose, is the pentagallic acid ester of glucose. It is a gallotannin and the precursor of ellagitannins.
Pentagalloylglucose can precipitate proteins, including human salivary α-amylase.
Natural occurrence Pentagalloylglucose can be found in Punica granatum (pomegranate), Elaeocarpus sylvestris, Rhus typhina (Staghorn sumac), Paeonia suffruticosa (Tree Peony), Mangifera indica (mango) and Bouea macrophylla Griffith (maprang).
Biosynthesis The enzyme beta-glucogallin-tetrakisgalloylglucose O-galloyltransferase catalyzes the chemical reaction which transfers the fifth and final gallic acid unit to a central glucose molecule to form pentagalloylglucose.
The enzyme was characterised from oak (Quercus robur).
Metabolism Tellimagrandin II is formed from pentagalloylglucose by oxidative dehydrogenation and coupling of 2 galloyl groups.
β-glucogallin: 1,2,3,4,6-pentagalloyl-β-D-glucose galloyltransferase is an enzyme found in the leaves of Rhus typhina that catalyzes the galloylation of 1,2,3,4,6-penta-O-galloyl-β-D-glucose to 3-O-digalloyl-1,2,4,6-tetra-O-galloyl-β-D-glucose (hexagalloylglucose).
Chemistry Pentagalloylglucose can undergo oxidation reactions which are depending on the pH.
Research Pentagalloylglucose has been studied for its potential use as an antimicrobial, anti-inflammatory, anticarcinogenic, antidiabetic, and antioxidant. It has also been studied for radioprotection. This compound helps stabilize the elastin and collagen in vascular tissues and restores the biomechanical properties of arterial ECM. In addition, pentagalloylglucose has shown to reduce arterial calcification and helps promote extracellular matrix preservation in animal models of abdominal aortic aneurysm. In vitro studies with mouse C2C12 myoblast cells have shown the PGG helps in lowering reactive oxygen species (ROS) and matrix metalloproteinase-2 (MMP-2) expression in a dose-dependent manner.
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