Ellagitannin
Encyclopedia
The ellagitannins are a diverse class of hydrolyzable tannins, a type of polyphenol
Polyphenol
Polyphenols are a structural class of natural, synthetic, and semisynthetic organic chemicals characterized by the presence of large multiples of phenol structural units...

 formed primarily from the oxidative linkage of galloyl groups in 1,2,3,4,6-Pentagalloyl glucose
1,2,3,4,6-Pentagalloyl glucose
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.Pentagalloyl glucose can precipitate proteins including human salivary α-amylase.-Biosynthesis:...

. Ellagitannins differ from gallotannin
Gallotannin
A gallotannin is a class of molecules belonging to the hydrolysable tannins. Gallotannins are polymers formed when gallic acid, a polyphenol monomer, esterifies and binds with the hydroxyl group of a polyol carbohydrate such as glucose.-Metabolism:...

s, in that their galloyl groups are linked through C-C bonds, whereas the galloyl groups in gallotannins are linked by depside
Depside
A depside is a type of polyphenolic compound composed of two or more monocyclic aromatic units linked by an ester bond. Depsides are most often found in lichens, but have also been isolated from higher plants, including species of the Ericaceae, Lamiaceae, Papaveraceae and Myrtaceae. Depsides have...

 bonds.

Particular ellagitannins such as casuarictin
Casuarictin
Casuarictin is an ellagitannin, a type of hydrolysable tannin. It can be found in Casuarina and Stachyurus species.The molecule is formed from tellimagrandin II, itself formed from pentagalloyl glucose via oxidation. Casuarictin is transformed into pedunculagin via loss of a gallate group, and...

 have be shown to have potential antiviral activity.

Examples

  • Castalagin
    Castalagin
    Castalagin is a ellagitannin, a type of hydrolyzable tannin, found in oak and chestnut wood and in the stem barks of Anogeissus leiocarpus and Terminalia avicennoides....

  • Castalin
    Castalin
    Castalin is an ellagitannin. It can be found in oak wood and in Melaleuca quinquenervia leaves....

  • Casuarictin
    Casuarictin
    Casuarictin is an ellagitannin, a type of hydrolysable tannin. It can be found in Casuarina and Stachyurus species.The molecule is formed from tellimagrandin II, itself formed from pentagalloyl glucose via oxidation. Casuarictin is transformed into pedunculagin via loss of a gallate group, and...

  • Grandinin
    Grandinin
    Grandinin is an ellagitannin. It can be found in Melaleuca quinquenervia leaves and in oaks. It shows antioxydant activity. It is a castalagin glycoside by binding of the pentose lyxose....

  • Punicalagin
    Punicalagin
    Punicalagin is an ellagitannin, a polyphenol compound which are isomers of 2,3--hexahydroxydiphenoyl-4,6--gallagyl-D-glucose, hydrolysable tannins with a molecular weight of 1084. They are found in forms alpha and beta in pomegranates...

  • Punicalin
  • Roburin A
    Roburin A
    Roburin A is a tannin found in oak wood or oak cork .It is a dimeric compound, composed of two vescalagin subunits probably linked through an ether bond between the diphenoyl group of one subunit and the triphenoyl moiety of the other one....

  • Tellimagrandin II
    Tellimagrandin II
    Tellimagrandin II is the first of the ellagitannins formed from 1,2,3,4,6-pentagalloyl-glucose. It can be found in Geum japonicum and Syzygium aromaticum . The compound shows anti-herpesvirus properties....

  • Terflavin B
    Terflavin B
    Terflavin B is a hydrolysable tannin. It can be found in Myrobalanus chebula , the black chebulic, and in Terminalia catappa, the Indian almond....

  • Vescalagin

Presence in food

The fruits of Rubus
Rubus
Rubus is a large genus of flowering plants in the rose family, Rosaceae, subfamily Rosoideae. Raspberries, blackberries, and dewberries are common, widely distributed members of the genus. Most of these plants have woody stems with prickles like roses; spines, bristles, and gland-tipped hairs are...

 are a concentrated sources of dietary ellagitannins.
The trimeric lambertianin C and the dimerics sanguiin H-6 are by far the major ellagitannins of Rubus berries. Lambertianin C is the major ellagitannin in blackberries and sanguiin H-6 the major ellagitannin in raspberries
Raspberries
Raspberry may refer to:* Raspberry, various fruit-bearing plants in the genus Rubus, especially two commercially grown species, the red-fruited Rubus idaeus and the black-fruited Rubus occidentalis...

. Besides these two compounds, another 20 minor related substances were detected and preliminarily characterized in Rubus extracts.

Further reading

Books
  • Quideau, Stéphane (editor). Chemistry and Biology of Ellagitannins: An Underestimated Class of Bioactive Plant Polyphenols, 2009, World Scientific Publishing. Table of Contents. Preface. Chapter 1.

Journal articles

External links

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