- Arachidonic acid
Name = Arachidonic acid
ImageFile = AAnumbering.png
ImageSize = 350px
IUPACName = "all-cis"-5,8,11,14-eicosatetraenoic acid
Section1 = Chembox Identifiers
CASNo = 506-32-1
SMILES = CCCCCC=CCC=CCC=CCC=CCCCC(=O)O
Section2 = Chembox Properties
Formula = C20H32O2.
MolarMass = 304.5 g/mol
MeltingPt = -49.5 °C
BoilingPt = °C (dec.)
Arachidonic acid (AA, sometimes ARA) is an
omega-6 fatty acid20:4(ω-6).It is the counterpart to the saturated arachidic acidfound in peanutoil, ("L. arachis – peanut".)cite web
title = Dorland's Medical Dictionary – 'A'
accessdate = 2007-01-12]
chemical structure, arachidonic acid is a carboxylic acidwith a 20-carbon chain and four " cis" double bonds; the first double bond is located at the sixth carbon from the omega end.
Some chemistry sources define 'arachidonic acid' to designate any of the
eicosatetraenoic acids. However, almost all writings in biology, medicine and nutrition limit the term to all-"cis" 5,8,11,14-eicosatetraenoic acid.
Arachidonic acid is a polyunsaturated fatty acid that is present in the
phospholipids (especially phosphatidylethanolamine, phosphatidylcholineand phosphatidylinositides) of membranes of the body's cells, and is abundant in the brain.
It is also involved in
cellular signalingas a second messenger.
It is the source of several other molecules with specific roles, as described in the next section.
ynthesis and cascade
Arachidonic acid is freed from
phospholipidmolecule by the enzyme phospholipase A2, which cleaves off the fatty acid.
Arachidonic acid is a precursor in the production of
* the enzymes
cyclooxygenaseand peroxidaselead to Prostaglandin H2, which in turn is used to produce the prostaglandins, prostacyclin, and thromboxanes.
* the enzyme
5-lipoxygenaseleads to 5-HPETE, which in turn is used to produce the leukotrienes.
* arachidonic acid is also used in the biosynthesis of
The production of these derivatives and their action in the body are collectively known as the "arachidonic acid cascade"; see
essential fatty acid interactionsfor more details.
Essential fatty acid
Arachidonic acid is one of the
essential fatty acids required by most mammals. Some mammals lack the ability to—or have a very limited capacity to—convert linoleic acidinto arachidonic acid, making it an essential part of their diet. Since little or no arachidonic acid is found in plants, such animals are obligate carnivores; the cat is a common example.cite journal
author=MacDonald M, Rogers Q, Morris J
title=Nutrition of the domestic cat, a mammalian carnivore
journal=Annu Rev Nutr |volume=4 |issue= |pages=521–62 |year=1984
doi=10.1146/annurev.nu.04.070184.002513] cite journal |author=Rivers J, Sinclair A, Crawford M |title=Inability of the cat to desaturate essential fatty acids |journal=Nature |url=http://www.nature.com/nature/journal/v258/n5531/abs/258171a0.html |doi=10.1038/258171a0|volume=258 |issue=5531 |pages=171–3 |year=1975 |pmid=1186900]
Polyunsaturated fatty acid
Aspirin- inhibits cyclooxygenaseenzyme to prevent the conversion of arachidonic acid to other signal molecules
* [http://www.acnp.org/g4/GN401000059/Default.htm Arachidonic Acid] at acnp.org
Wikimedia Foundation. 2010.