Hexahydroxydiphenic acid is an organic compound with the formula
HO)3C6HCO2Hsub>2. It is the oxidatively coupled derivative of
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 plants. It i ...
It is a white solid, although samples are typically brown owing to oxidation.
left, 142px, Ellagic acid.
Hexahydroxydiphenic acid is a component of some
ellagitannin
The ellagitannins are a diverse class of hydrolyzable tannins, a type of polyphenol formed primarily from the oxidative linkage of galloyl groups in 1,2,3,4,6-pentagalloyl glucose. Ellagitannins differ from gallotannins, in that their galloyl group ...
s,
such as
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, ...
.
Luteic acid
Luteic acid is a natural phenol found in numerous fruits. It is a monolactonized tergalloyl group. Maximilian Nierenstein showed in 1945 that luteic acid was a molecule present in the myrobalanitannin, a tannin found in the fruit of ''Terminalia ch ...
is the monolactone and
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 backwards because it can be ob ...
is the di
lactone
Lactones are cyclic carboxylic esters, containing a 1-oxacycloalkan-2-one structure (), or analogues having unsaturation or heteroatoms replacing one or more carbon atoms of the ring.
Lactones are formed by intramolecular esterification of the co ...
of hexahydroxydiphenic acid.
See also
*
Diphenic acid
References
Ellagitannins
Pyrogallols
Biphenyls
Hydroxybenzoic acids
{{phenol-stub
