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.

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. It typically occurs in nature as a triglyceride (ester of glycerin) rather than as a free fatty acid. It is one of two essential fatty acids for humans, who must obtain it through their diet, 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.

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^Y
3D model (JSmol)	Interactive image
Beilstein Reference	1727101
ChEBI	CHEBI:17351^Y
ChEMBL	ChEMBL267476^Y
ChemSpider	4444105^Y
DrugBank	DB14104
ECHA InfoCard	100.000.428
EC Number	200-470-9
Gmelin Reference	57557
IUPHAR/BPS	1052
KEGG	C01595^Y
PubChem CID	5280450
UNII	9KJL21T0QJ^Y
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-^Y Key: OYHQOLUKZRVURQ-HZJYTTRNSA-N^Y 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 (pK_a)	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). Y verify (what is ^YN ?) Infobox references