Arachidonic acid
- 5Z, 8Z, 11Z, 14Z - eicosatetraenoic
- Z, Z, Z, Z - 5 ,8,11,14 - tetra - eicosapentaenoic acid
- All-Z - 5 ,8,11,14 - tetra - eicosapentaenoic acid
- 20:4 ( ω -6) (lipid Name )
Colorless, clear liquid
Liquid
0.922 g · cm -3
-49.5 ° C
169-171 ° C (20 Pa)
Practically insoluble in water but readily soluble in nonpolar solvents (benzene )
1.4824 (20 ° C)
Template: Infobox chemical / molecular formula search available
Arachidonic acid (from the Latin arachis = " peanut ", short form of AA engl. Arachidonic Acid ) is a four polyunsaturated fatty acid. In contrast to the fully saturated arachidic acid, which was isolated from peanut, arachidonic acid is not present in plants.
Occurrence and biological significance
Arachidonic acid is in each animal organism from the essential omega -6 fatty acid linoleic acid via the intermediate stages γ -linolenic acid ( GLA) and dihomo- γ -linolenic acid ( DGLA ) synthesized or obtained from food. It is found as a component of lipids such as phospholipids.
Arachidonic acid is located in an esterified ( physiologically inactive ) form as a lipid component in particular in the cell membranes and may be regulated by the activity of the enzyme phospholipase A2 (often from 1,2- diacylglycerols DAG) liberated. To inhibit cortisol and vitamin E phospholipase and can positively influence inflammatory processes as for example in joint diseases such as osteoarthritis of the activated and other forms of arthritis. The lowest possible recording or synthesis of arachidonic acid appear to be very desirable in this context to health in most cases. In inflammatory autoimmune diseases ( esp. in multiple sclerosis, but also in Autoimmunthyreopathien and rheumatism ) is often recommended a diet that is low in arachidonic acid. This relationship may in future be confirmed in relation to ulcerative colitis. According to an analysis in the context of the EPIC study after, ulcerative colitis occurred more frequently in individuals who had a higher intake of linoleic acid, although from these study results, no direct dietary recommendations can be inferred.
Metabolism
Arachidonic acid has (simplified) three ways of further metabolism:
- About the cyclooxygenases arise prostaglandins,
- On the lipoxygenases occur leukotrienes and
- Arise through various forms of cytochrome P450-dependent Epoxygenases among others Epoxyeicosatrienoic acids ( EETs ).
About this way she is involved among other things in the complex regulation of fever and inflammation. This affects, for example, a gain of cyclooxygenase -2 triggering fever, an amplification of the cytochrome P450-dependent Epoxygenasenweges However, in various ways, directly and indirectly fever suppressing or limiting. Aspirin and ibuprofen not only inhibit the cyclooxygenase pathway, but also induce the Epoxygenaseweg; its metabolites inhibit cyclooxygenases turn himself stronger than these medicines themselves.
Arachidonic acid in foods
Arachidonic acid is found in many foods. Especially high is their share in lard (1700 mg per 100 g), pork liver (870 mg per 100 g), egg yolk (297 mg per 100 g), tuna (280 mg per 100 g) and liver sausage (230 mg per 100 g). Additionally, it may result in an increased hormone- driven introduction into the cells in diabetic diet rich. Stark linoleic acid vegetable oils and derived products contain hardly even the pure arachidonic acid, however, bear building materials contribute to their formation and suppress additional natural enemies of arachidonic acid (eg omega-3 fatty acids).