Naturally occurring unsaturated fatty acids: Arachidonic acid

Arachidonic acid, which is polyunsaturated fatty acid, is used in the animal body for a number of biological functions. Arachidonic acid (AA), all-cis-5, 8, 11, 14-eicosatetraenoic acid (where eicos or eikosi in Greek refers to the number 20), is an omega-6 polyunsaturated fatty acid (PUFA).
Its chemical formula is C20H32O2, 20:4(ω -6), where 20:4 refers to its 20 carbon atom chain with four double bonds, and (ω -6) refers to the position of the first double bond from the last, omega carbon atom. Arachidonic acid has an average mass of 304.467 g/mol and usually assumes a hairpin structure.

It is a component of phospholipid membranes and is a precursor to an extensive group of compounds called eicosanoids. Three of them: prostaglandins, leukotrienes and thromboxanes are largely responsible for the regulation of inflammatory processes.

Arachidonic acid can be stored in membrane phospholipids and released from nuclear envelop or plasma membrane by cytosolic phospholipase A2 (cPLA2), either constitutively or in respond to a variety of cell specific stimuli, including growth factors, hormones, cytokines, signaling molecules, or cell trauma.

Arachidonic acid can be provided to humans and mammals by an exogenous source supplied either by the direct consumption of dietary food that contains high level of arachidonic acid, whole eggs, salmon, tuna, a wide range of lean meat and its visible meat fats, or through the parent molecule, linoleic acid (LA; 18:2n-6).
Naturally occurring unsaturated fatty acids: Arachidonic acid