1,2,3,4,6-Pentagalloyl glucose

1,2,3,4,6-Pentagalloyl glucose
IUPAC name

[(2S,3R,4S,5R,6R)-2,3,5-tris[(3,4,5-trihydroxybenzoyl)oxy]-6-[(3,4,5-trihydroxybenzoyl)oxymethyl]oxan-4-yl] 3,4,5-trihydroxybenzoate
Other names

1,2,3,4,6-penta-O-galloyl-β-D-glucose
1,2,3,4,6-pentakis-O-galloyl-beta-D-glucose
beta-penta-O-galloyl-glucose
PGG
Identifiers
CAS number 14937-32-7 N=
PubChem 65238
ChemSpider 58735 Y
ChEBI CHEBI:18082 Y
ChEMBL CHEMBL382408 Y
Jmol-3D images Image 1
Properties
Molecular formula C41H32O26
Molar mass 940.67 g/mol
Exact mass 940.118181 u
 N (verify) (what is: Y/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

1,2,3,4,6-Pentagalloyl glucose is the pentahydroxy gallic acid ester of glucose. It is the common precursor of gallotannins and the related ellagitannins.[1]

Pentagalloyl glucose can precipitate proteins[2] including human salivary α-amylase.[3]

Contents

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

Metabolism of ellagitannins

Tellimagrandin II, first of all ellagitannins, forms from pentagalloyl glucose by oxydative 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, the staghorn sumac, that catalyses 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).[4]

Chemistry

Pentagalloyl glucose can undergo oxidation reactions which are depending on the pH.[5]

References

  1. ^ Biosynthesis of gallotannins: β-Glucogallin-dependent formation of 1,2,3,4,6-pentagalloylglucose by enzymatic galloylation of 1,2,3,6-tetragalloylglucose. Cammann J., Denzel K., Schilling G. and Gross G. G., Archives of Biochemistry and Biophysics, Volume 273, Issue 1, 15 August 1989, Pages 58-63
  2. ^ Mechanisms of protein precipitation for two tannins, pentagalloyl glucose and epicatechin16 (4→8) catechin (procyanidin). Hagerman A. E., Rice M. E. and Ritchard N. T., Journal of agricultural and food chemistry, 1998, vol. 46, no7, pp. 2590-2595
  3. ^ Evidence for pentagalloyl glucose binding to human salivary α-amylase through aromatic amino acid residues. Gyöngyi Gyémánt, Ágnes Zajácz, Bálint Bécsi, Chandran Ragunath, Narayanan Ramasubbu, Ferenc Erdődi, Gyula Batta and Lili Kandra, Biochimica et Biophysica Acta (BBA) - Proteins & Proteomics, Volume 1794, Issue 2, February 2009, pp. 291-296
  4. ^ Gallotannin biosynthesis: purification of β-glucogallin: 1,2,3,4,6-pentagalloyl-β-d-glucose galloyltransferase from sumac leaves. Phytochemistry, Volume 49, Issue 2, 28 September 1998, pp. 327-332, doi:10.1016/S0031-9422(98)00014-4
  5. ^ Reaction pH and protein affect the oxidation products of β-pentagalloyl glucose. Yumin C. and Hagerman A.E., Free radical research, 2005, vol. 39, no2, pp. 117-124
Types of gallotannins
Aglycones
Examples
Burkinabin A | B | C | Galloyl glucose | Digalloyl glucose | Trigalloyl glucose: 1,2,6-Trigalloyl glucose / 1,3,6,-Trigalloyl glucose (Corilagin) | Tetragalloyl glucose: 1,2,3,6-tetragalloylglucose | Pentagalloyl glucose: 1,2,3,4,6-pentagalloyl-glucose and 6-digalloyl-1,2,3-trigalloyl-glucose | Hexagalloyl glucose | Heptagalloyl glucose | Octagalloyl glucose | Nonagalloyl glucose | Decagalloyl glucose | 1,3,4-Tri-O-galloylquinic acid | 3,4,5-Tri-O-galloylquinic acid | 3,5-di-O-galloyl-shikimic acid | 3,4,5-tri-O-galloylshikimic acid | 1,2,6-trigalloyl alloside | 1,3,6-trigalloyl alloside | 1,2,3,6-tetragalloyl alloside