Linoleic acid

Linoleic acid
Names
	Preferred IUPAC name (9Z,12Z)-Octadeca-9,12-dienoic acid
	Other names cis,cis-9,12-Octadecadienoic acid; C18:2 (Lipid numbers)
Identifiers
CAS Number	60-33-3 ;
3D model (JSmol)	Interactive image;
Beilstein Reference	1727101
ChEBI	CHEBI:17351 ;
ChEMBL	ChEMBL267476 ;
ChemSpider	4444105 ;
DrugBank	DB14104;
ECHA InfoCard	100.000.428
EC Number	200-470-9;
Gmelin Reference	57557
IUPHAR/BPS	1052;
KEGG	C01595 ;
PubChem CID	5280450;
UNII	9KJL21T0QJ ;
CompTox Dashboard (EPA)	DTXSID2025505 ;
	InChI InChI=1S/C18H32O2/c1-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16-17-18(19)20/h6-7,9-10H,2-5,8,11-17H2,1H3,(H,19,20)/b7-6-,10-9- Key: OYHQOLUKZRVURQ-HZJYTTRNSA-N ; InChI=1/C18H32O2/c1-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16-17-18(19)20/h6-7,9-10H,2-5,8,11-17H2,1H3,(H,19,20)/b7-6-,10-9- Key: OYHQOLUKZRVURQ-HZJYTTRNBX;
	SMILES CCCCC/C=C\C/C=C\CCCCCCCC(=O)O;
Properties
Chemical formula	C18H32O2
Molar mass	280.452 g·mol−1
Appearance	Colorless oil
Density	0.9 g/cm3
Melting point	−12 °C (10 °F); −6.9 °C (19.6 °F); −5 °C (23 °F)
Boiling point	229 °C (444 °F) at 16 mmHg; 230 °C (446 °F) at 21 mbar; 230 °C (446 °F) at 16 mmHg
Solubility in water	0.139 mg/L
Vapor pressure	16 Torr at 229 °C
Acidity (pKa)	4.77 at 25°C
Hazards
NFPA 704 (fire diamond)	2 1 0
Flash point	112 °C (234 °F)
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Linoleic acid (LA) is an organic compound with the formula HOOC(CH₂)₇CH=CHCH₂CH=CH(CH₂)₄CH₃. Both alkene groups (−CH=CH−) are cis. It is a fatty acid sometimes denoted 18:2 (n−6) or 18:2 cis-9,12. A linoleate is a salt or ester of this acid.^[5]

Linoleic acid is a polyunsaturated, omega−6 fatty acid. It is a colorless liquid that is virtually insoluble in water but soluble in many organic solvents.^[2] It typically occurs in nature as a triglyceride (ester of glycerin) rather than as a free fatty acid.^[6] It is one of two essential fatty acids for humans, who must obtain it through their diet,^[7] and the most essential, because the body uses it as a base to make the others.

The word "linoleic" derives from Latin linum 'flax' and oleum 'oil', reflecting the fact that it was first isolated from linseed oil.

^ ^a ^b ^c The Merck Index, 11th Edition, 5382
^ ^a ^b ^c William M. Haynes (2016). CRC Handbook of Chemistry and Physics (97th ed.). Boca Raton: CRC Press. pp. 3–338. ISBN 978-1-4987-5429-3.
^ ^a ^b ^c ^d Record of CAS RN 60-33-3 in the GESTIS Substance Database of the Institute for Occupational Safety and Health
^ National Center for Biotechnology Information (2024). PubChem Compound Summary for CID 5280450, Linoleic Acid. Retrieved January 20, 2024 from https://pubchem.ncbi.nlm.nih.gov/compound/Linoleic-Acid.
^ "Fatty Acids". Cyber Lipid. Archived from the original on 28 October 2018. Retrieved 31 July 2017.
^ Mattes, Richard D. (2009). "Is there a fatty acid taste?". Annual Review of Nutrition. 29: 305–327. doi:10.1146/annurev-nutr-080508-141108. PMC 2843518. PMID 19400700.
^ Simopoulos, Artemis P. (2008). "The importance of the omega-6/omega-3 fatty acid ratio in cardiovascular disease and other chronic diseases". Experimental Biology and Medicine. 233 (6): 674–688. doi:10.3181/0711-mr-311. PMID 18408140. S2CID 9044197.

[Merck-1] The Merck Index, 11th Edition, 5382

[crc97-2] William M. Haynes (2016). CRC Handbook of Chemistry and Physics (97th ed.). Boca Raton: CRC Press. pp. 3–338. ISBN 978-1-4987-5429-3.

[GESTIS-3] Record of CAS RN 60-33-3 in the GESTIS Substance Database of the Institute for Occupational Safety and Health

[pubchem-4] National Center for Biotechnology Information (2024). PubChem Compound Summary for CID 5280450, Linoleic Acid. Retrieved January 20, 2024 from https://pubchem.ncbi.nlm.nih.gov/compound/Linoleic-Acid.

[5] "Fatty Acids". Cyber Lipid. Archived from the original on 28 October 2018. Retrieved 31 July 2017.

[Is_there_a_fatty_acid_taste-6] Mattes, Richard D. (2009). "Is there a fatty acid taste?". Annual Review of Nutrition. 29: 305–327. doi:10.1146/annurev-nutr-080508-141108. PMC 2843518. PMID 19400700.

[7] Simopoulos, Artemis P. (2008). "The importance of the omega-6/omega-3 fatty acid ratio in cardiovascular disease and other chronic diseases". Experimental Biology and Medicine. 233 (6): 674–688. doi:10.3181/0711-mr-311. PMID 18408140. S2CID 9044197.

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