130px, Castalagin is a representative ellagitannin, characterized by coupled gallic acid substituents The ellagitannins are a diverse class of

hydrolyzable tannin A hydrolysable tannin or pyrogallol-type tannin is a type of tannin that, on heating with hydrochloric or sulfuric acids, yields gallic or ellagic acids. At the center of a hydrolysable tannin molecule, there is a carbohydrate (usually D-gluc ...

s, a type of

polyphenol Polyphenols () are a large family of naturally occurring phenols. They are abundant in plants and structurally diverse. Polyphenols include phenolic acids, flavonoids, tannic acid, and ellagitannin, some of which have been used historically as ...

formed primarily from the oxidative linkage of

galloyl Gallic acid (also known as 3,4,5-trihydroxybenzoic acid) is a trihydroxybenzoic acid with the formula C6 H2( OH)3CO2H. It is classified as a phenolic acid. It is found in gallnuts, sumac, witch hazel, tea leaves, oak bark, and other plant ...

groups in 1,2,3,4,6-pentagalloyl glucose. Ellagitannins differ from

gallotannin A gallotannin is any of 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. Met ...

s, in that their

groups are linked through C-C bonds, whereas the galloyl groups in gallotannins are linked by

depside A depside is a type of polyphenolic compound composed of two or more monocyclic aromatic units linked by an ester group. Depsides are most often found in lichens, but have also been isolated from higher plants, including species of the Ericaceae, ...

bonds. Ellagitannins contain various numbers of

hexahydroxydiphenoyl Hexahydroxydiphenic acid is an organic compound with the formula HO)3C6HCO2Hsub>2. It is the oxidatively coupled derivative of gallic acid It is a white solid, although samples are typically brown owing to oxidation. Occurrence left, 142px, ...

units, as well as

units and/or sanguisorboyl units bounded to sugar moiety. In order to determine the quantity of every individual unit, the hydrolysis of the extracts with

trifluoroacetic acid Trifluoroacetic acid (TFA) is a synthetic organofluorine compound with the chemical formula CF3CO2H. It belongs to the subclass of per- and polyfluoroalkyl substances (PFASs) known as ultrashort-chain perfluoroalkyl acids (PFAAs). TFA is not ...

methanol Methanol (also called methyl alcohol and wood spirit, amongst other names) is an organic chemical compound and the simplest aliphatic Alcohol (chemistry), alcohol, with the chemical formula (a methyl group linked to a hydroxyl group, often ab ...

/water system is performed. Hexahydroxydiphenic acid, created after hydrolysis, spontaneously lactonized to

ellagic acid Ellagic acid is a polyphenol found in numerous fruits and vegetables. It is the dilactone of hexahydroxydiphenic acid. Name The name comes from the French term ''acide ellagique'', from the word ''galle'' spelled backward because it can be o ...

, and

sanguisorbic acid Sanguisorbic acid is a constituent of some ellagitannins. It is constituted by a hexahydroxydiphenic acid unit linked by an O-C bond to a gallic acid. The differences with its isomers, valoneic acid and nonahydroxytriphenic acid, are that the hydr ...

to sanguisorbic acid dilactone, while

gallic acid Gallic acid (also known as 3,4,5-trihydroxybenzoic acid) is a trihydroxybenzoic acid with the formula C6 H2( OH)3CO2H. It is classified as a phenolic acid. It is found in gallnuts, sumac, witch hazel, tea leaves, oak bark, and other plant ...

remains intact. Ellagitannins generally form

macrocycle Macrocycles are often described as molecules and ions containing a ring of twelve or more atoms. Classical examples include the crown ethers, calixarenes, porphyrins, and cyclodextrins. Macrocycles describe a large, mature area of chemistry. ...

s, whereas gallotannins do not.

Examples

Castalagin Castalagin is an ellagitannin, a type of hydrolyzable tannin, found in oak and chestnut wood and in the stem barks of ''Terminalia leiocarpa'' and ''Terminalia avicennoides''. Castalagin is the diastereomer of vescalagin in C-1 of the glycosidic c ...

* Castalin *

Casuarictin Casuarictin is an ellagitannin, a type of hydrolysable tannin. It can be found in ''Casuarina'' and ''Stachyurus'' species.Tannins of Casuarina and Stachyurus species. I: Structures of pendunculagin, casuarictin, strictinin, casuarinin, casuariin, ...

Grandinin Grandinin is an ellagitannin. It can be found in ''Melaleuca quinquenervia'' leaves and in oaks species like the North American white oak (''Quercus alba'') and European red oak (''Quercus robur''). It shows antioxydant activity. It is an astringe ...

* Oenothein B from Willowherbs (Epilobium spp.) *

Roburin A Roburin A is a tannin found in oak wood (''Quercus robur'' and ''Quercus petraea'' or ''Quercus alba'') or oak cork ('' Quercus suber''). It is a dimeric compound, composed of two vescalagin Castalagin is an ellagitannin, a type of hydrolyzable t ...

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'' (clove).Purification and Characterization of Eugeniin as an Anti-herpesvirus Compou ...

* Terflavin B *

Vescalagin Castalagin is an ellagitannin, a type of hydrolyzable tannin, found in oak and chestnut wood and in the stem barks of ''Terminalia leiocarpa'' and ''Terminalia avicennoides''. Castalagin is the diastereomer of vescalagin in C-1 of the glycosidic c ...

Pomegranate ellagitannin The pomegranate ellagitannins, which include punicalagin isomers, are ellagitannins found in the sarcotestas, rind (peel), bark or heartwood of the pomegranate fruit (''Punica granatum''). Chemistry As the chemistry of punicalagins became kno ...

s, many compounds **

Punicalagin Punicalagin (''Pyuni-cala-jen'') is an ellagitannin, a type of phenolic compound. It is found as alpha and beta isomers in pomegranates (''Punica granatum''), '' Terminalia catappa'', '' Terminalia myriocarpa'', and in '' Combretum molle'', the ...

Punicalin Punicalin is an ellagitannin. It can be found in '' Punica granatum'' (pomegranate) or in the leaves of '' Terminalia catappa'', a plant used to treat dermatitis and hepatitis. It is also reported in '' Combretum glutinosum'', all three species ...

Metabolism

Degradation

Urolithins, such as

urolithin A Urolithin A is a metabolite compound resulting from the transformation of ellagitannins by the gut bacteria. It belongs to the class of organic compounds known as benzo-coumarins or dibenzo-α-pyrones. Its precursors – ellagic acids and ellagit ...

, are microflora human metabolites of dietary

derivatives.

Natural occurrences

Ellagitannins are reported in

dicotyledon The dicotyledons, also known as dicots (or, more rarely, dicotyls), are one of the two groups into which all the flowering plants (angiosperms) were formerly divided. The name refers to one of the typical characteristics of the group: namely, ...

eous angiospermes, and notably in species in the order

Myrtales The Myrtales are an order of flowering plants in the malvid clade of the rosid group of dicotyledons. Well-known members of Myrtales include: myrtle, pōhutukawa, bay rum tree, clove, guava, acca (feijoa), allspice, eucalyptus, crape myrtles, ...

, such as the

pomegranate The pomegranate (''Punica granatum'') is a fruit-bearing deciduous shrub in the family Lythraceae, subfamily Punica, Punicoideae, that grows between tall. Rich in symbolic and mythological associations in many cultures, it is thought to have o ...

References

External links

Tannin Chemistry
(Tannin Handbook, Copyright 1998, 2002, 2011, Ann E. Hagerman) {{Ellagitannin Aromatase inhibitors Wood extracts

Examples

Metabolism

Degradation

Natural occurrences

See also

Other links

References

Further reading

External links