Formula C41H32O26 | Molar mass 940.67 g/mol | |
1,2,3,4,6-Pentagalloylglucose is the pentagallic acid ester of glucose. It is a gallotannin and the precursor of ellagitannins.
Contents
Pentagalloyl glucose can precipitate proteins including human salivary α-amylase.
It may also be used in radioprotection.
Natural occurrence
1,2,3,4,6-Pentagalloyl glucose can be found in Punica granatum (pomegranate), Elaeocarpus sylvestris, Rhus typhina (Staghorn sumac), and Paeonia suffruticosa (Tree Peony).
Biosynthesis
The enzyme beta-glucogallin-tetrakisgalloylglucose O-galloyltransferase uses 1-O-galloyl-beta-D-glucose and 1,2,3,6-tetrakis-O-galloyl-beta-D-glucose to produce D-glucose and pentagalloyl glucose.
Metabolism of ellagitannins
Tellimagrandin II is formed from pentagalloyl glucose 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 (hexa-galloylglucose).
Chemistry
Pentagalloyl glucose can undergo oxidation reactions which are depending on the pH.