Editing Α-Linolenic acid

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{{About|α-Linolenic acid||Linolenic acid}}
{{Use dmy dates|date=August 2020}}
{{lowercase title}}
{{chembox
| Watchedfields = changed
| verifiedrevid = 477319349
| Name = α-Linolenic acid
| ImageFile = ALAnumbering.svg 
| ImageSize = 250px
| ImageFile1 = Linolenic-acid-3D-vdW.png
| ImageSize1 = 250px
| PIN = (9''Z'',12''Z'',15''Z'')-Octadeca-9,12,15-trienoic acid<ref>{{cite journal | last1 = Loreau | first1 = O | last2 = Maret | first2 = A | last3 = Poullain | first3 = D | last4 = Chardigny | first4 = JM | last5 = Sébédio | first5 = JL | last6 = Beaufrère | first6 = B | last7 = Noël | first7 = JP | title = Large-scale preparation of (9Z,12E)-[1-<sup>13</sup>C]-octadeca-9,12-dienoic acid, (9Z,12Z,15E)-[1-<sup>13</sup>C]-octadeca-9,12,15-trienoic acid and their 1-<sup>13</sup>C all-cis isomers | journal = Chemistry and Physics of Lipids | volume = 106 | issue = 1 | pages = 65–78 | year = 2000 | pmid = 10878236 | doi = 10.1016/S0009-3084(00)00137-7}}</ref>
| OtherNames = ALA; LNA; Linolenic acid; ''cis'',''cis'',''cis''-9,12,15-Octadecatrienoic acid; (9''Z'',12''Z'',15''Z'')-9,12,15-Octadecatrienoic acid; Industrene 120
| Section1 = {{Chembox Identifiers
| IUPHAR_ligand = 1049
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 4444437
| PubChem = 5280934
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 0RBV727H71
| InChI = 1/C18H30O2/c1-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16-17-18(19)20/h3-4,6-7,9-10H,2,5,8,11-17H2,1H3,(H,19,20)/b4-3-,7-6-,10-9-
| ChEBI_Ref = {{ebicite|correct|EBI}}
| ChEBI = 27432
| DrugBank_Ref = {{drugbankcite|correct|drugbank}}
| DrugBank = DB00132
| SMILES = O=C(O)CCCCCCC\C=C/C\C=C/C\C=C/CC
| InChIKey = DTOSIQBPPRVQHS-PDBXOOCHBH
| SMILES1 = CC/C=C\C/C=C\C/C=C\CCCCCCCC(=O)O
| ChEMBL_Ref = {{ebicite|correct|EBI}}
| ChEMBL = 8739
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/C18H30O2/c1-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16-17-18(19)20/h3-4,6-7,9-10H,2,5,8,11-17H2,1H3,(H,19,20)/b4-3-,7-6-,10-9-
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = DTOSIQBPPRVQHS-PDBXOOCHSA-N
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo = 463-40-1
  }}
| Section2 = {{Chembox Properties
| C = 18 | H = 30 | O = 2
| Density = 0.9164 g/cm<sup>3</sup>
| MeltingPt = {{convert|−11|C|F K}}<ref name="Kim2014" />
| BoilingPt = {{convert|232|C|F K}} at 17.0 mmHg<ref name="Kim2014"> Kim, K.-B.; Nam, Y. A.; Kim, H. S.; Hayes, A. W.; Lee, B.-M. [https://www.sciencedirect.com/science/article/abs/pii/S0278691514002439?via%3Dihub α-Linolenic acid: Nutraceutical, pharmacological and toxicological evaluation]. Food and Chemical Toxicology 2014, 70, 163–178.</ref>
}}
}}

'''α-Linolenic acid''', also known as  '''''alpha''-linolenic acid''' ('''ALA''') (from [[Greek language|Greek]] ''alpha'' meaning "first" and ''linon'' meaning [[flax]]), is an [[omega-3 fatty acid|''n''−3]], or omega-3, [[essential fatty acid]]. ALA is found in many seeds and oils, including [[flaxseed]], [[walnut]]s, [[chia seed|chia]], [[hemp]], and many common [[vegetable oil]]s.

In terms of its [[IUPAC nomenclature of organic chemistry|structure]], it is named ''all''-''cis''-9,12,15-octadecatrienoic acid.<ref name=Beare>{{cite web
|author =Beare-Rogers
|title=IUPAC Lexicon of Lipid Nutrition
|year=2001
|url=http://www.iupac.org/publications/pac/2001/pdf/7304x0685.pdf
| access-date=22 February 2006
| archive-url= https://web.archive.org/web/20060212173746/http://www.iupac.org/publications/pac/2001/pdf/7304x0685.pdf| archive-date= 12 February 2006 | url-status= live}}</ref> In physiological literature, it is listed by its lipid number, 18:3 (''n''−3). It is a [[carboxylic acid]] with an 18-carbon chain and three ''[[Cis–trans isomerism|cis]]'' [[double bond]]s. The first double bond is located at the third carbon from the methyl end of the fatty acid chain, known as the ''n'' end. Thus, α-linolenic acid is a [[polyunsaturated fatty acid|polyunsaturated]] ''n''−3 (omega-3) fatty acid. It is a [[regioisomer]] of [[gamma-linolenic acid]] (GLA), an 18:3 (''n''−6) fatty acid (i.e., a polyunsaturated [[omega-6 fatty acid]] with three double bonds).

==Etymology==
The word ''linolenic'' is an irregular derivation from ''linoleic'', which itself is derived from the [[Greek language|Greek]] word ''linon'' ([[flax]]). ''Oleic'' means "of or relating to [[oleic acid]]" because saturating an omega-6 double bond of [[linoleic acid]] produces oleic acid.  Similarly saturating one of linolenic acid's double bonds produces linoleic acid.

==Dietary sources==
{{See also|Vegetable oil#Composition of fats}}
Seed oils are the richest sources of α-linolenic acid, notably those of hempseed, [[Salvia hispanica|chia]], [[Perilla oil|perilla]], [[flaxseed]] ([[linseed oil]]), [[rapeseed]] ([[canola]]), and [[soybean]]s. α-Linolenic acid is also obtained from the [[thylakoid|thylakoid membranes]] in the leaves of ''[[Pisum sativum]]'' (pea leaves).<ref>{{cite journal
  |author1=Chapman, David J. |author2=De-Felice, John |author3=Barber, James |journal=Plant Physiol |date=May 1983|volume=72 | issue=1|pages=225–228
  |title=Growth temperature effects on thylakoid membrane lipid and protein content of pea chloroplasts 1
  |pmid=16662966
  |doi= 10.1104/pp.72.1.225
  |pmc= 1066200}}</ref> Plant [[chloroplast]]s consisting of more than 95 percent of photosynthetic thylakoid membranes are highly fluid due to the large abundance of ALA, evident as sharp resonances in high-resolution carbon-13 NMR spectra.<ref>YashRoy R.C. (1987) 13-C NMR studies of lipid fatty acyl chains of chloroplast membranes. ''Indian Journal of Biochemistry and Biophysics'' vol. 24(6), pp. 177–178.https://www.researchgate.net/publication/230822408_13-C_NMR_studies_of_lipid_fatty_acyl_chains_of_chloroplast_membranes?ev=prf_pub</ref> Some studies state that ALA remains stable during processing and cooking.<ref>{{cite journal|title=Processing and cooking effects on lipid content and stability of alpha-linolenic acid in spaghetti containing ground flaxseed. | pmid=11879055 | volume=50 | issue=6 | year=2002 | journal=J. Agric. Food Chem. | pages=1668–71 | doi=10.1021/jf011147s| last1=Manthey | first1=F. A. | last2=Lee | first2=R. E. | last3=Hall | first3=C. A. }}</ref> However, other studies state that ALA might not be suitable for baking as it will [[polymer]]ize with itself, a feature exploited in [[Drying oil|paint]] with transition metal catalysts. Some ALA may also oxidize at baking temperatures.<ref>{{cite web|url=http://serials.unibo.it/cgi-ser/start/it/spogli/df-s.tcl?prog_art=3832218&language=ITALIANO&view=articoli|title=OXIDATIVE STABILITY OF FLAXSEED LIPIDS DURING BAKING|access-date=30 December 2012|archive-date=16 October 2015|archive-url=https://web.archive.org/web/20151016210119/http://serials.unibo.it/cgi-ser/start/it/spogli/df-s.tcl?prog_art=3832218&language=ITALIANO&view=articoli|url-status=live}}</ref> ALA percentages in the table below refer to the oils extracted from each item.

{| class="wikitable" style="border-collapse:collapse;"
!|Common name||Alternate name||Linnaean name||% ALA<sup>†</sup>(of oil)||ref.
|-
|[[Chia seed|Chia]] ||chia sage||''Salvia hispanica''||64% ||<ref name=sofadb>{{Cite web |url=http://sofa.mri.bund.de/ |title=Seed Oil Fatty Acids – SOFA Database Retrieval |access-date=26 March 2018 |archive-date=9 November 2018 |archive-url=https://web.archive.org/web/20181109135217/http://sofa.mri.bund.de/ |url-status=live }}</ref>
|-
|[[Kiwifruit]] seeds||Chinese gooseberry||''Actinidia chinensis''||62%||<ref name=sofadb />
|-
|[[Perilla]]||shiso||''Perilla frutescens''||58%||<ref name=sofadb />
|-
|[[Flax]]||linseed||''Linum usitatissimum''||55%||<ref name=sofadb />
|-
|[[Cowberry|Lingonberry]]||cowberry||''Vaccinium vitis-idaea''||49%||<ref name=sofadb />
|-
|[[Camelina sativa|Camelina]]||camelina||''Camelina sativa''||37%||<ref name= Juodka >{{cite journal |vauthors=Juodka R, Nainiené R, Juškiené V, Juška R, Leikus R, Kadžiené G, Stankevičiené D |date=January 2022 |title=Camelina (''Camelina sativa'' (L.) Crantz) as Feedstuffs in Meat Type Poultry Diet: A Source of Protein and n-3 Fatty Acids |journal=Animals |volume=12 |issue=3 |at=Table 3 |doi=10.3390/ani12030295 |doi-access=free|pmid=35158619 |pmc=8833380 }}</ref>
|-
|[[Portulaca|Purslane]]||portulaca||''Portulaca oleracea''||35%||<ref name=sofadb />
|- 
|[[Cuckoo flower]]||mayflower||''Cardamine pratensis''||35%||<ref name= Bederska-Łojewska >{{cite journal |vauthors=Bederska-Łojewska D, Pieszka M, Marzec A, Rudzińska M, Grygier A, Siger A, Cieślik-Boczula K, Orczewska-Dudek S, Migdał W |date=December 2021 |title=Physicochemical Properties, Fatty Acid Composition, Volatile Compounds of Blueberries, Cranberries, Raspberries, and Cuckooﬂower Seeds Obtained Using Sonication Method |journal=Molecules |volume=26 |issue=24 |at=Table 2 |doi=10.3390/molecules26247446 |doi-access=free|pmid=34946523 |pmc=8704999 }}</ref>
|-
|[[Cranberry]]||American cranberry||''Vaccinium macrocarpon''||35%||{{r|Bederska-Łojewska}}
|-
| [[Sea buckthorn]] ||seaberry ||''Hippophae rhamnoides'' L.||32%||<ref name=Li>{{cite conference
  | first = Thomas S. C.
  | last = Li
  | title = Sea buckthorn: New crop opportunity
  | book-title = Perspectives on new crops and new uses
  | pages = 335–337
  | publisher = [[ASHS Press]] 
  | year = 1999
  | location = Alexandria, VA
  | url = http://www.hort.purdue.edu/newcrop/proceedings1999/v4-335.html
  | access-date =  2006-10-28| archive-url= https://web.archive.org/web/20060922084707/http://www.hort.purdue.edu/newcrop/proceedings1999/v4-335.html| archive-date= 22 September 2006 | url-status= live}}</ref>
|-
|[[Raspberry]]||raspberry||''Rubus idaeus''||31%||{{r|Bederska-Łojewska}}
|-
|[[Blueberry]]||[[bilberry]]||''Vaccinium myrtillus'' L.||29%||{{r|Bederska-Łojewska}}
|- 
|[[Hemp]]||cannabis||''Cannabis sativa''||20%||<ref name=sofadb />
|- 
|[[Walnut oil|Walnut]]||English walnut / Persian walnut||''Juglans regia''||10.4%||<ref>{{Cite web |url=http://www.umm.edu/altmed/articles/omega-3-000316.htm |title=Omega-3 fatty acids |publisher=University of Maryland Medical Center|archive-url=https://web.archive.org/web/20091227023806/http://www.umm.edu/altmed/articles/omega-3-000316.htm |archive-date=27 December 2009 }}</ref>
|-
|[[Rapeseed]]||canola||''Brassica napus''||10%||<ref name=Beare />
|-
| [[Soybean oil|Soybean]] ||soya||''Glycine max''||8%||<ref name=Beare />
|-
| colspan=3|&nbsp;
| colspan=2|<small><sup>†</sup>average value</small>
|}

==Metabolism==
[[Image:Beklädnadsväxter, Linum usitatissimum, Nordisk familjebok.png|thumb|100px|right|[[Flax]] is a rich source of α-linolenic acid.]]

α-Linolenic acid can be obtained by humans only through their diets.  Humans lack the [[desaturase]] enzymes required for processing [[stearic acid]] into A-linoleic acid or other unsaturated fatty acids. 

Dietary α-linolenic acid is metabolized to [[stearidonic acid]], a precursor to a collection of polyunsaturated 20-, 22-, 24-, etc fatty acids ([[eicosatetraenoic acid]], [[eicosapentaenoic acid]], [[docosapentaenoic acid]], tetracosapentaenoic acid, [[nisinic acid|6,9,12,15,18,21-tetracosahexaenoic acid]], [[docosahexaenoic acid]]).<ref>{{cite journal |author1=Breanne M Anderson |author2=David WL Ma | year = 2009 
| title = Are all n-3 polyunsaturated fatty acids created equal? | pages = 33 
| journal = Lipids in Health and Disease 
| volume = 8 
| issue = 33 
| doi = 10.1186/1476-511X-8-33 |doi-access=free|pmid=19664246 |pmc=3224740 }}</ref> 
Because the efficacy of ''n''−3 long-chain polyunsaturated fatty acid (LC-PUFA) synthesis decreases down the cascade of α-linolenic acid conversion, DHA synthesis from α-linolenic acid is even more restricted than that of EPA.<ref>{{cite journal
| author=Shiels M. Innis
| year = 2007
| title = Fatty acids and early human development
| journal = [[Early Human Development]]
| volume = 83
| pages = 761–766
| doi = 10.1016/j.earlhumdev.2007.09.004
| pmid=17920214
| issue=12
}}</ref> Conversion of ALA to DHA is higher in women than in men. This is likely due to the increased need for DHA in women in order to support a developing fetus and in producing breastmilk containing DHA.<ref name=":0">{{cite journal | last1 = Burdge | first1 = GC | last2 = Calder | first2 = PC | title = Conversion of alpha-linolenic acid to longer-chain polyunsaturated fatty acids in human adults | journal = Reproduction, Nutrition, Development | volume = 45 | issue = 5 | pages = 581–597 | year = 2005 | pmid = 16188209 | doi = 10.1051/rnd:2005047 | url = http://rnd.edpsciences.org/articles/rnd/pdf/2005/05/r5505.pdf | doi-access = free | access-date = 4 November 2018 | archive-date = 15 August 2017 | archive-url = https://web.archive.org/web/20170815122704/https://rnd.edpsciences.org/articles/rnd/pdf/2005/05/r5505.pdf | url-status = live }}</ref>

===Stability and hydrogenation===
Compared to many other oils, α-linolenic acid is more susceptible to oxidation. It [[rancidification|becomes rancid]] more quickly in air. [[Rancidification|Oxidative instability]] of α-linolenic acid is one reason why producers choose to partially [[Hydrogenation|hydrogenate]] oils containing α-linolenic acid, such as [[soybean oil]].<ref name= Kinney >{{cite web
 |author=Kinney, Tony 
 |title=Metabolism in plants to produce healthier food oils (slide #4) 
 |url=http://www.metabolicengineering.gov/me2005/Kinney.pdf 
 |access-date=2007-01-11 
 |url-status=dead 
 |archive-url=https://web.archive.org/web/20060929134832/http://www.metabolicengineering.gov/me2005/Kinney.pdf 
 |archive-date=29 September 2006 
}}</ref> [[Soybean]]s are the largest source of edible oils in the U.S., and, as of a 2007 study, 40% of soy oil production was partially hydrogenated.<ref>{{cite journal|url=http://www.truthabouttrade.org/article.asp?id=6669 |title=Ban on trans fat could benefit Iowa |journal=Truth About Trade and Technology |access-date=2007-01-03 |author1=Fitzgerald, Anne  |author2=Brasher, Philip |url-status=dead |archive-url=https://web.archive.org/web/20070927012419/http://www.truthabouttrade.org/article.asp?id=6669 |archive-date=27 September 2007 }}</ref> 

Hydrogenation of ALA-containing fats can introduce [[trans fat]]s. Consumers are increasingly avoiding products that contain trans fats, and governments have begun to ban trans fats in food products, including the US government as of May 2018.<ref>{{Cite journal |last=Program |first=Human Foods |date=2024-09-06 |title=Trans Fat |url=https://www.fda.gov/food/food-additives-petitions/trans-fat |journal=FDA |language=en}}</ref> These regulations and market pressures have spurred the development of soybeans low in α-linolenic acid. These new soybean varieties yield a more stable oil that often do not require hydrogenation for many applications.<ref>{{cite web
 |url         = http://www.monsanto.com/monsanto/layout/media/06/01-12-06.asp
 |author      = Monsanto
 |title       = ADM to process Monsanto's Vistive low linolenic soybeans at Indiana facility
 |access-date  = 2007-01-06
 |archive-url  = https://web.archive.org/web/20061211071206/http://www.monsanto.com/monsanto/layout/media/06/01-12-06.asp
 |archive-date = 11 December 2006
 |url-status   = dead}}</ref>

===Health===
ALA is an [[essential fatty acid]], meaning consumption of ALA in the diet is required for human life,<ref>{{Cite web |title=Office of Dietary Supplements - Omega-3 Fatty Acids |url=https://ods.od.nih.gov/factsheets/Omega3FattyAcids-HealthProfessional/ |access-date=2025-04-04 |website=ods.od.nih.gov |language=en}}</ref> along with all other [[Mammal|mammals]].<ref name=":0" /> ALA consumption is associated with a lower risk of [[cardiovascular disease]] and a reduced risk of fatal coronary heart disease.<ref>{{cite journal|vauthors=Sala-Vila A, Fleming J, Kris-Etherton P, Ros E|year=2022|title=Impact of α-Linolenic Acid, the Vegetable ω-3 Fatty Acid, on Cardiovascular Disease and Cognition|journal=Advances in Nutrition|url=https://academic.oup.com/advances/article/13/5/1584/6529227|volume=13|issue=5|pages=1584–1602|doi=10.1093/advances/nmac016|pmid=35170723 |pmc=9526859}}</ref><ref>{{cite journal |vauthors=Pan A, Chen M, Chowdhury R |title=α-Linolenic acid and risk of cardiovascular disease: a systematic review and meta-analysis |journal=Am. J. Clin. Nutr. |volume=96 |issue=6 |pages=1262–73 |date=December 2012  |pmid=23076616 |pmc=3497923 |doi=10.3945/ajcn.112.044040 |type=Systematic review|display-authors=etal}}</ref> Dietary ALA intake can improve lipid profiles by decreasing [[triglyceride]]s, [[total cholesterol]], [[high-density lipoprotein]], and [[low-density lipoprotein]].<ref>{{cite journal|vauthors=Hao Y, Bin Q, Min J, Wei L, Xiao-fei G, Na L, Zhi-xiang X, Fang-ling D, Tongcheng X, Duo L|year=2020|title=Effects of α-linolenic acid intake on blood lipid profiles：a systematic review and meta-analysis of randomized controlled trials|url=https://www.tandfonline.com/doi/abs/10.1080/10408398.2020.1790496|journal=Critical Reviews in Food Science and Nutrition|volume=61|issue=17|pages=2894–2910|doi=10.1080/10408398.2020.1790496|pmid=32643951|s2cid=220439436|access-date=14 December 2021|archive-date=14 December 2021|archive-url=https://web.archive.org/web/20211214200928/https://www.tandfonline.com/doi/abs/10.1080/10408398.2020.1790496|url-status=live}}</ref> A 2021 review found that ALA intake is associated with a reduced risk of mortality from all causes, cardiovascular disease, and coronary heart disease but a slightly higher risk of cancer mortality.<ref>{{cite journal|vauthors=Naghshi S, Aune D, Beyene J, Mobarak S, Asadi M, Sadeghi O|year=2021|title=Research Dietary intake and biomarkers of alpha linolenic acid and risk of all cause, cardiovascular, and cancer mortality: systematic review and dose-response meta-analysis of cohort studies|url=https://www.bmj.com/content/375/bmj.n2213|journal=The BMJ|volume=375|issue=|pages=n2213|pmid=34645650|doi=10.1136/bmj.n2213|pmc=8513503|access-date=14 December 2021|archive-date=14 December 2021|archive-url=https://web.archive.org/web/20211214185932/https://www.bmj.com/content/375/bmj.n2213|url-status=live}}</ref>

==History==
In 1887, linolenic acid was discovered and named by the Austrian chemist Karl Hazura of the Imperial Technical Institute at Vienna (although he did not separate its isomers).<ref>{{cite journal |last1=Hazura |first1=K. |title=Über trocknende Ölsäuren IV. Abhandlung |journal=Monatshefte für Chemie |date=1887 |volume=8 |pages=260–270 |doi=10.1007/BF01510049 |s2cid=197767239 |url=https://babel.hathitrust.org/cgi/pt?id=uiug.30112025862258&view=1up&seq=272 |trans-title=On drying oily acids 4th paper |language=de |access-date=1 November 2020 |archive-date=18 January 2021 |archive-url=https://web.archive.org/web/20210118132255/https://babel.hathitrust.org/cgi/pt?id=uiug.30112025862258&view=1up&seq=272 |url-status=live }}  Linolenic acid is named on p. 265:  ''"Für die Säure C<sub>18</sub>H<sub>32</sub>O<sub>2</sub> schlage ich den Namen Linolsäure, für die Säure C<sub>18</sub>H<sub>30</sub>O<sub>2</sub> den Namen Linolensäure vor."'' (For the acid C<sub>18</sub>H<sub>32</sub>O<sub>2</sub> I suggest the name "linolic acid"; for the acid C<sub>18</sub>H<sub>30</sub>O<sub>2</sub> [I suggest] the name "linolenic acid".)  Linolenic acid is discussed on pp. 265-268.</ref>  α-Linolenic acid was first isolated in pure form in 1909 by Ernst Erdmann and F. Bedford of the [[Martin Luther University of Halle-Wittenberg|University of Halle an der Saale]], Germany,<ref>See:
* {{cite journal |last1=Erdmann |first1=E. |last2=Bedford |first2=F. |title=Über die im Leinöl enthaltene Linolensäure |journal=Berichte der Deutschen Chemischen Gesellschaft |date=1909 |volume=42 |pages=1324–1333 |doi=10.1002/cber.190904201217 |url=https://babel.hathitrust.org/cgi/pt?id=iau.31858002459612&view=1up&seq=1334 |trans-title=On linolenic acid [that's] contained in flax oil |language=de |access-date=31 October 2020 |archive-date=26 January 2021 |archive-url=https://web.archive.org/web/20210126064447/https://babel.hathitrust.org/cgi/pt?id=iau.31858002459612&view=1up&seq=1334 |url-status=live }} On p. 1329 they distinguish one of the isomers of linolenic acid:  ''"Wir bezeichnen diese in Leinöl vorhandene Linolensäure, welche das feste Hexabromid liefert, zum Unterschied von einer später zu erwähnenden Isomeren als α-Linolensäure."''  (We designate this linolenic acid, which the solid hexabromide [of linolenic acid] provides, as α-linolenic acid in order to distinguish [it] from an isomer [that will be] mentioned later.)
* {{cite journal |last1=Erdmann |first1=E. |last2=Bedford |first2=F. |last3=Raspe |first3=F. |title=Konstitution der Linolensäure |journal=Berichte der Deutschen Chemischen Gesellschaft |date=1909 |volume=42 |pages=1334–1346 |doi=10.1002/cber.190904201218 |url=https://babel.hathitrust.org/cgi/pt?id=iau.31858002459612&view=1up&seq=1344 |trans-title=Structure of linolenic acid |language=de |access-date=31 October 2020 |archive-date=1 February 2021 |archive-url=https://web.archive.org/web/20210201195930/https://babel.hathitrust.org/cgi/pt?id=iau.31858002459612&view=1up&seq=1344 |url-status=live }} The structure of α-linolenic acid appears on p. 1343.</ref> and by Adolf Rollett of the [[Freie Universität Berlin|Universität Berlin]], Germany,<ref>{{cite journal | author = Rollett, A. | journal = Zeitschrift für physiologische Chemie | volume = 62 | pages = 422–431 | year = 1909 | doi = 10.1515/bchm2.1909.62.5-6.422 | title = Zur Kenntnis der Linolensäure und des Leinöls | trans-title = [Contribution to our] knowledge of linolenic acid and flax oil | issue = 5–6 | url = https://zenodo.org/record/1448776 | access-date = 1 July 2019 | archive-date = 18 March 2020 | archive-url = https://web.archive.org/web/20200318192331/https://zenodo.org/record/1448776 | url-status = live }}</ref> working independently, as cited in J. W. McCutcheon's synthesis in 1942,<ref>{{OrgSynth | prep=cv3p0531 | author = J. W. McCutcheon | title = Linolenic acid | collvol = 3 | collvolpages = 351 | year = 1955}}</ref> and referred to in Green and Hilditch's 1930s survey.<ref>{{cite journal | last1 = Green | first1 = TG | last2 = Hilditch | first2 = TP | title = The identification of linoleic and linolenic acids | journal = [[Biochem. J.]] | volume = 29 | issue = 7 | pages = 1552–63 | year = 1935 | pmc = 1266662 | pmid = 16745822 | doi = 10.1042/bj0291552 }}</ref> It was first artificially synthesized in 1995 from C6 homologating agents. A Wittig reaction of the phosphonium salt of [(''Z-Z'')-nona-3,6-dien-1-yl]triphenylphosphonium bromide with methyl 9-oxononanoate, followed by [[saponification]], completed the synthesis.<ref>{{cite journal |author1=Sandri, J. |author2=Viala, J. | year = 1995 | title = Direct preparation of (''Z'',''Z'')-1,4-dienic units with a new C6 homologating agent: synthesis of α-linolenic acid | pages = 271–275 | journal = [[Synthesis (journal)|Synthesis]] | volume = 1995 | doi = 10.1055/s-1995-3906 | issue = 3|s2cid=196696819 }}</ref>

==See also==
*[[Canola oil]]
*[[Flax seed oil]]
*[[γ-Linolenic acid]]
*[[Drying oil]]
*[[Essential fatty acid]]
*[[List of omega-3 fatty acids|List of ''n''−3 fatty acids]]
*[[Essential nutrient]]
*[[Wheat germ oil]]

==References==
{{reflist}}

{{Fatty acids}}

{{DEFAULTSORT:Linolenic acid, alpha-}}
[[Category:5α-Reductase inhibitors]]
[[Category:Fatty acids]]
[[Category:Essential fatty acids]]
[[Category:Essential nutrients]]
[[Category:Alkenoic acids]]
[[Category:Semiochemicals]]
[[Category:Insect pheromones]]