# Isanic acid

> Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Isanic_acid
> Markdown URL: https://mediated.wiki/source/Isanic_acid.md
> Source: https://en.wikipedia.org/wiki/Isanic_acid
> Source revision: 1338898109
> License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/)

{{Chembox
<!-- Images -->
| Name           = Isanic acid
| ImageFile      = Isanic acid.png
| ImageSize      = 250px
| ImageAlt       = <!-- Names -->
| IUPACName      = octadec-17-en-9,11-diynoic acid
| OtherNames     = Erythrogenic acid
| Section1       = {{Chembox Identifiers
| CASNo          = 506-25-2
| CASNo_Ref      = {{Cascite|changed|CAS}}
| ChemSpiderID   = 4472111
| DTXSID         = DTXSID701304957
| EC_number      = 
| ChEBI          = 197116
| UNII           = JEO6512256
| PubChem        = 5312686
| InChI          = InChI=1S/C18H26O2/c1-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16-17-18(19)20/h2H,1,3-6,11-17H2,(H,19,20)
| InChIKey       = OASRDXXKKGHDJZ-UHFFFAOYSA-N
| SMILES         = OC(=O)CCCCCCCC#CC#CCCCCC=C
}}
| Section2       = {{Chembox Properties
| H=26|O=2|C=18
| MolarMass      = 
| Appearance     = crystalline platelets or prisms, light-sensitive; turns red
| Density        = 
| MeltingPtC     = 
| BoilingPtC     = 
| BoilingPt_ref  = 
| Solubility     = 
  }}
| Section3       = {{Chembox Hazards
| GHSPictograms  = 
| GHSSignalWord  = 
| GHS_ref        =
| HPhrases       = 
| PPhrases       = 
| MainHazards    = 
| FlashPt        = 
| AutoignitionPt = 
  }}
}}
'''Isanic acid''' or erythrogenic acid is a linear fatty acid composed of 18 carbon atoms, with two [triple bond](/source/triple_bond)s in the positions 9≡10 and 11≡12 and a [double bond](/source/double_bond) in the position 17=18. This is one of the rare polyacetylenic acids with [conjugated](/source/Conjugated_system) triple bonds. Its delta notation is 18:3Δ9a,11a,17. Its structural formula is CH<sub>2</sub>=CH-(CH<sub>2</sub>)<sub>4</sub>–C≡C–C≡C–(CH<sub>2</sub>)<sub>7</sub>–COOH.<ref>{{cite web |title=NCATS Inxight Drugs — ISANIC ACID |url=https://drugs.ncats.io/drug/JEO6512256 |publisher=drugs.ncats.io |access-date=10 April 2025 |language=en}}</ref>

[Exocarpic acid](/source/Exocarpic_acid) is isomeric to isanic acid. The related [isanolic acid](/source/isanolic_acid), unlike isanic acid, contains an additional [hydroxyl group](/source/hydroxyl_group). The oxygenated isanic acid is called [ketoisanic acid](/source/ketoisanic_acid).

==Discovery==
Isanic acid was initially isolated in 1937 by researchers A. Steger and J. van Loon<ref>{{cite journal |last1=Steger |first1=A. |last2=van Loon |first2=J. |title=Das fette Oel der Samen von Onguekoa Gore Engler |journal=Fette und Seifen |date=1937 |volume=44 |issue=6 |pages=243–246 |doi=10.1002/lipi.19370440608 |url=https://onlinelibrary.wiley.com/doi/10.1002/lipi.19370440608 |access-date=10 April 2025 |language=en |issn=1521-4133|url-access=subscription }}</ref> in the oil of the seeds of ''[Ongokea gore](/source/Ongokea_gore)'' or ''Ongokea klaineana'', a plant from equatorial Africa, called in the native language "boleka" or "isane", hence the common name of isanic acid.<ref>{{cite book |title=Vegetable oils |date=2007 |publisher=PROTA |isbn=978-90-5782-191-2 |page=128 |url=https://books.google.com/books?id=YW-ZbQnWQYsC&dq=Isanic+acid&pg=PA128 |access-date=25 April 2025 |language=en}}</ref><ref>{{cite book |first1=Oil and Colour Chemists Association of Australia|last1=St |title=Surface Coatings: Vol I-Raw Materials and Their Usage |date=9 March 2013 |publisher=[Springer Science & Business Media](/source/Springer_Science_%26_Business_Media) |isbn=978-94-011-6940-0 |page=24 |url=https://books.google.com/books?id=P0fqCAAAQBAJ&dq=Isanic+acid&pg=PA24 |access-date=25 April 2025 |language=en}}</ref> The oil seeds contain about 60% lipids.<ref name="Black"/> Various analyses have revealed the concentration of isanic acid in isane oil from 32% to 51%.

==Synthesis==
The synthesis of isanic acid is possible starting from 10-undecynoic acid.<ref name="Black">{{cite journal |last1=Black |first1=H. K. |last2=Weedon |first2=B. C. L. |title=368. Unsaturated fatty acids. Part I. The synthesis of erythrogenic (isanic) and other acetylenic acids |journal=[Journal of the Chemical Society (Resumed)](/source/Journal_of_the_Chemical_Society_(Resumed)) |date=1 January 1953 |pages=1785–1793 |doi=10.1039/JR9530001785 |url=https://pubs.rsc.org/en/content/articlelanding/1953/jr/jr9530001785 |access-date=10 April 2025 |language=en |issn=0368-1769|url-access=subscription }}</ref>

==Physical properties==
Isanic acid can be detected together with its isomers with the double bond in position 13=14: [boletic acid](/source/boletic_acid) and [exocarpic acid](/source/exocarpic_acid), and hydroxylated fatty acids, such as [isanolic acid](/source/isanolic_acid).{{cn|date=February 2026}}{{clarify|date=February 2026}}

The high degree of unsaturation suggests that oils with a high content of these conjugated acetylenic fatty acids are drying. Isanic acid polymerizes easily,<ref>{{cite book |title=Surface Coatings: Vol I-Raw Materials and Their Usage |date=9 March 2013 |publisher=[Springer Science & Business Media](/source/Springer_Science_%26_Business_Media) |isbn=978-94-011-6940-0 |page=24 |url=https://books.google.com/books?id=P0fqCAAAQBAJ&dq=Isanic+acid&pg=PA24 |access-date=10 April 2025 |language=en}}</ref> turning a bright red color when exposed to light. Because of this characteristic the alternative name of erythrogenic acid was proposed by Castille in 1940.<ref name="Black"/>

Insoluble in ether.<ref>{{cite book |title=Journal of the Chemical Society |date=1896 |publisher=Chemical Society |page=638 |url=https://books.google.com/books?id=8704AQAAMAAJ&dq=Isanic+acid&pg=PA638 |access-date=10 April 2025 |language=en}}</ref>

== References ==
<references/>

{{Fatty acids}}

Category:Alkenoic acids
Category:Fatty acids
Category:Conjugated diynes

---
Adapted from the Wikipedia article [Isanic acid](https://en.wikipedia.org/wiki/Isanic_acid) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Isanic_acid?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.