Omega-9 fatty acid
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2008-07-08T16:33:13Z
146.101.201.218
Removed annotation
{{For2|an explanation of ''n'' and numerical nomenclature (such as ''n''−9 or 18:1)|[[Fatty acid#Nomenclature|Nomenclature of fatty acids]]}}
{{Fats}}
'''''n''−9 fatty acids''' (popularly referred to as '''ω−9 fatty acids''' or '''omega-9 fatty acids''') are a family of [[unsaturated fat|unsaturated]] [[fatty acid]]s which have in common a carbon–carbon [[double bond#Bond order|double bond]] in the [[essential fatty acid#Nomenclature and terminology|''n''−9]] position; that is, the ninth bond from the end of the fatty acid.
==Background==
Some ''n''−9s are common components of [[animal fat]] and [[vegetable oil]]. Two ''n''−9 fatty acids important in industry are:
* [[Oleic acid]] (18:1, ''n''−9), which is a main component of [[olive oil]] and other [[monounsaturated fat]]s
* [[Erucic acid]] (22:1, ''n''−9), which is found in [[rapeseed]], [[wallflower]] seed, and [[mustard seed]]. Rapeseed with high erucic acid content is grown for commercial use in paintings and coatings as a [[drying oil]].
Unlike [[Omega-3 fatty acids|''n''−3]] and [[Omega-6 fatty acids|''n''−6]] fatty acids, ''n''−9 fatty acids are not classed as [[essential fatty acids]] (EFA). This is both because they can be created by the human body from [[unsaturated fat]], and are therefore not essential in the diet, and because the lack of an ''n''−6 double bond keeps them from participating in the reactions that form the [[eicosanoid]]s.
Under severe conditions of EFA deprivation, mammals will elongate and desaturate oleic acid to make [[mead acid]], (20:3, ''n''−9).<ref name="lipomics">{{cite web|url=http://www.lipomics.com/resources/fatty_acids/20_3n9.htm |author=Lipomics|title = Mead acid| accessdate= February 14|accessyear = 2006}}</ref> This also occurs to a lesser extent in [[vegetarians]] and semi-vegetarians.<ref name="phinney1990">{{cite web| author=Phinney, SD, RS Odin, SB Johnson and RT Holman |title=Reduced arachidonate in serum phospholipids and cholesteryl esters associated with vegetarian diets in humans|url=http://intl.ajcn.org/cgi/content/abstract/51/3/385|accessdate=February 11|accessyear=2006|year=1990}}</ref>
==List of ''n''−9 fatty acids==
{| class="wikitable"
! Common name
! Lipid name
! Chemical name
|-
! [[oleic acid]]
| 18:1 (''n''−9)
| 9-octadecenoic acid
|-
! [[eicosenoic acid]]
| 20:1 (''n''−9)
| 11-eicosenoic acid
|-
! [[mead acid]]
| 20:3 (''n''−9)
| 5,8,11-eicosatrienoic acid
|-
! [[erucic acid]]
| 22:1 (''n''−9)
| 13-docosenoic acid
|-
! [[nervonic acid]]
| 24:1 (''n''−9)
| 15-tetracosenoic acid
|}
==See also==
* [[Polyunsaturated fatty acid]], lists of fatty acids including ''n''−3, ''n''−6, and ''n''−9 fatty acids
* [[Omega-3 fatty acid|''n''−3 fatty acid]]
* [[Omega-6 fatty acid|''n''−6 fatty acid]]
==References==
{{reflist}}
===Additional references===
{{refbegin}}
* {{cite web|author=Cyberlipid Center| title= Polyenoic fatty acids| url= http://www.cyberlipid.org/fa/acid0003.htm | accessdate=February 11| accessyear=2006}}
{{refend}}
{{Lipids}}
[[Category:Fatty acids|ω]]
[[de:Omega-9-Fettsäure]]
[[es:Ácidos grasos omega 9]]
[[fr:Oméga-9]]
[[pt:Ômega 9]]