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 , from the word
galle spelled backward
because it can be obtained from
noix de galle (
), and to distinguish it from
acide gallique (
gallic acid). The molecular structure resembles to that of two gallic acid molecules being assembled "head to tail" and bound together by a C–C bond (as in
biphenyl, or in
diphenic acid) and two
lactone links (cyclic
).
Metabolism
Biosynthesis
Plants produce ellagic acid from hydrolysis of
tannins such as
ellagitannin and
geraniin.
Biodegradation
are
gut flora human metabolites of dietary ellagic acid derivatives.
Ellagic acid has low bioavailability, with 90% remaining unabsorbed from the intestines until metabolized by microflora to the more bioavailable urolithins.
History
Ellagic acid was first discovered by chemist
Henri Braconnot in 1831.
Maximilian Nierenstein prepared this substance from
algarobilla,
dividivi, oak bark,
pomegranate, myrabolams, and
valonea in 1905.
[ He also suggested its formation from galloyl-glycine by Penicillium in 1915.]
Natural occurrences
Ellagic acid is found in edible nuts.
The macrophyte Myriophyllum spicatum produces ellagic acid.
Ellagic acid can be found in the medicinal mushroom Phellinus linteus.
In food
The highest levels of ellagic acid are found in raw chestnuts, , , cranberry, raspberry, strawberry, and grapes, as well as distilled beverages.
Research and health claims
Ellagic acid has been marketed as a dietary supplement with various claimed benefits against cancer, heart disease, and other diseases. In the 21st century, numerous U.S.-based supplement companies received FDA warning letters for promoting ellagic acid with false health claim that violate the Federal Food, Drug, and Cosmetic Act.[
]
See also
-
List of ineffective cancer treatments
