Linoleic acidLA

PUFA18:2Ω-6 Essential

  Overview

Stats

PUFA
Type
18
Carbons
2
Double bonds
1
Bis-allylic sites
280.45
Weight · g/mol
-6.9 °C
Melting point
C18H32O2
Formula

Also known as

IUPAC (9Z,12Z)-octadeca-9,12-dienoic acid
Synonyms

  At a Glance

Key Points

The most abundant polyunsaturated fat in most vegetable oils (18:2 n-6), with both double bonds cis.

Source

Essential — must be obtained from the diet. Primarily from plant oils and meat.

Type

Long-chain polyunsaturated fatty acid with 18 carbons and two cis double bonds, an omega-6 fatty acid.

Identification

  Synonyms

Common Name Linoleic acid
IUPAC Name (9Z,12Z)-octadeca-9,12-dienoic acid
Traditional Name —
Other Synonyms
  • cis-9, cis-12-octadecadienoic acid
  • cis,cis-Linoleic acid
  • cis,cis-9,12-Octadecadienoic acid
  • Linoleate
  • 9Z,12Z-Linoleic acid
  • Telfairic acid
  • C18:2n-6,9
  • Linolic acid
  • Leinolic acid

  External IDs

General References
Wikipedia Linoleic_acid
Lipids
Lipid Maps LMFA01030120
Lipid Bank DFA0159
Swiss Lipids 000000407
PlantFA ID 10090
Food & Nutrition
FooDB FDB006287
INFOODS F18D2CN6
Chemistry / Compounds
PubChem CID 5280450
CAS 60-33-3
ChEBI 17351
ChEMBL CHEMBL267476
ChemSpider 4444105
InChIKey —
ZINC ID ZINC000004474613
NIKKAJI ID J4.801A
PDBe EIC
UCI (UniChem) 404393
SureChEMBL SCHEMBL7067
CCDC LINOLA
NMRShiftDB 60018537
Metabolites & Pathways
HMDB HMDB0000673
METLIN 191
RefMet ID —
RefMet Name —
MetaboLights ID MTBLS10446
BioCyc/MetaCyc LINOLEIC_ACID
MetaNetX ID MNXM293
BiGG ID lnlc
KEGG C01595
KNApSAcK C00001224
Reactome ID —
Drugs & Pharmacology
DrugBank DB14104
DrugCentral 3323
BindingDB 22231
Guide to Pharm 1052
Probes & Drugs PD013641
Clinical & Medical
SNOMED-CT 8822004
MeSH D019787
NCIt Code C615
Regulatory
NIH UNII (USA) 9KJL21T0QJ
FDA SRS (USA) 9KJL21T0QJ
NHPID (Canada) —
DTXSID (USA) DTXSID2025505
TGA Ing ID (Australia) —
Commercial Suppliers
MolPort Molport-001-780-227
eMolecules 524840, 26755855
Mcule —
ChemicalBook CB5764024
MedChemExpress HY-N0729

Isomers of 18:2 (7)

Other fatty acids sharing the 18:2 notation — differing by double-bond position, geometry (cis/trans), or conjugation.

Name Geometry Trans Structure PubChem
Current Fatty Acid
Linoleic acid
(9Z,12Z)-octadeca-9,12-dienoic acid
 9Z,12Z —
5280450
Category —
Conjugation Type Isolated
SMILES CCCCC\C=C/C\C=C/CCCCCCCC(O)=O
Description —
Origin Details

No origin information recorded.
Geometric (3)
Linoelaidic acid
(9E,12E)-octadeca-9,12-dienoic acid
 9E,12E Trans
5282457
Category —
Conjugation Type Isolated
SMILES CCCCC\C=C\C/C=C/CCCCCCCC(=O)O
Description —
Origin Details

No origin information recorded.
9Z,12E-Octadecadienoic Acid
(9Z,12E)-octadeca-9,12-dienoic acid
 9Z,12E Trans
Category Isolated mono-trans Fatty Acid
Conjugation Type Isolated
SMILES CCCCC/C=C/C\C=C/CCCCCCCC(=O)O
Description A mono-trans geometric isomer where only the delta-12 double bond has been flipped into the E configuration.
Origin Details
Origin Source Type Details
Thermal/Refining Degradation Cooking Formed during high-temperature industrial deodorization, chemical refining processes, or extended deep-frying of seed oils.
9E,12Z-Octadecadienoic Acid
(9E,12Z)-octadeca-9,12-dienoic acid
 9E,12Z Trans
6442998
Category Isolated mono-trans Fatty Acid
Conjugation Type Isolated
SMILES CCCCC\C=C/C/C=C/CCCCCCCC(=O)O
Description A mono-trans geometric isomer where only the delta-9 double bond has been converted to the E conformation.
Origin Details
Origin Source Type Details
Thermal/Refining Degradation Cooking Generated via free radical-mediated isomerization during the severe thermal stress or commercial processing of plant lipid matrices.
Positional (3)
Rumenic acid
(9Z,11E)-octadeca-9,11-dienoic acid
 9Z,11E Trans
5280644
Category —
Conjugation Type Conjugated
SMILES CCCCCC\C=C\C=C/CCCCCCCC(O)=O
Description —
Origin Details

No origin information recorded.
(10E,12Z)-Octadecadienoic acid
(10E,12Z)-octadeca-10,12-dienoic acid
 10E,12Z Trans
5282800
Category —
Conjugation Type Conjugated
SMILES CCCCC/C=C\C=C\CCCCCCCCC(=O)O
Description —
Origin Details

No origin information recorded.
9E,11E-CLA
(9E,11E)-octadeca-9,11-dienoic acid
 9E,11E Trans
5460677
Category Conjugated trans-trans Fatty Acid
Conjugation Type Conjugated
SMILES CCCCCC/C=C/C=C/CCCCCCCC(=O)O
Description The fully conjugated di-trans isomer, possessing the highest melting point of the 18:2 series due to its straight linear structural stacking capabilities.
Origin Details
Origin Source Type Details
Severe Thermal Conversion Cooking Formed through the rigorous thermal degradation or extreme catalytic processing of standard conjugated linoleic acids.

Chemical Properties

Name(s):
Common Name Linoleic acid
Abbreviation LA
Simple Notation 18:2
Notation 18:2(n-6)
IUPAC Name (9Z,12Z)-octadeca-9,12-dienoic acid
Structure:
Molecular C18H32O2
Structure CH3(CH2)4CH=CHCH2CH=CH(CH2)7COOH
SMILES CCCCC\C=C/C\C=C/CCCCCCCC(O)=O
InChIKey OYHQOLUKZRVURQ-HZJYTTRNSA-N
Cis / Trans cis
E-Z 9Z,12Z
Physical:
Weight 280.45 g/mol
Melting Point -6.9 °C
Reactivity
Double Bonds 2
Bis-Allylic Carbons 1 (High Reactivity)
Beta-Oxidation
Beta Oxidation Cycles 8
ATP Yield (Net) 117 ATP