# List of unsaturated fatty acids

| ω−n | Common Name | Lipid Numbers | Δ$^n$ | Structural Formula | Trans or Cis | Naturally Occurring in |
| ω−3 | α-Linolenic acid | C18:3 | Δ$^{9,12,15}$ | CH$_3$CH$_2$CH=CHCH$_2$CH=CHCH$_2$CH=CH(CH$_2$)$_7$COOH | cis | flaxseeds, chia seeds, walnuts |
| ω−3 | Stearidonic acid | C18:4 | Δ$^{6,9,12,15}$ | CH$_3$CH$_2$CH=CHCH$_2$CH=CHCH$_2$CH=CHCH$_2$CH=CH( CH$_2$)$_4$COOH | cis | seed oils of hemp, blackcurrant, corn gromwell |
| ω−3 | Eicosapentaenoic acid | C20:5 | Δ$^{5,8,11,14,17}$ | CH$_3$CH$_2$CH=CHCH$_2$CH=CHCH$_2$CH=CHCH$_2$CH=CHCH$_2$ CH=CH(CH$_2$)$_3$COOH | cis | cod liver, herring, mackerel, salmon, menhaden and sardine |
| ω−3 | Cervonic acid | C22:6 | Δ$^{4,7,10,13,16,19}$ | CH$_3$CH$_2$CH=CHCH$_2$CH=CHCH$_2$CH=CHCH$_2$CH=CHCH$_2$ CH=CHCH$_2$CH=CH(CH$_2$)$_2$COOH | cis | maternal milk, fish oil |
| ω−6 | Linoleic acid | C18:2 | Δ$^{9,12}$ | CH$_3$(CH$_2$)$_4$CH=CHCH$_2$CH=CH(CH$_2$)$_7$COOH | cis | peanut oil, chicken fat, olive oil |
| ω−6 | Linolelaidic acid | C18:2 | Δ$^{9,12}$ | CH$_3$(CH$_2$)$_4$CH=CHCH$_2$CH=CH(CH$_2$)$_7$COOH | trans | partially hydrogenated vegetable oils |
| ω−6 | γ-Linolenic acid | C18:3 | Δ$^{6,9,12}$ | CH$_3$(CH$_2$)$_4$CH=CHCH$_2$CH=CHCH$_2$CH=CH(CH$_2$)$_4$COOH | cis | borage oil, black currant oil, evening primrose oil and safflower oil |
| ω−6 | Dihomo-γ-linolenic acid | C20:3 | Δ$^{8,11,14}$ | CH$_3$(CH$_2$)$_4$CH=CHCH$_2$CH=CHCH$_2$CH=CH(CH$_2$)$_6$COOH | cis | only in trace amounts in animal products |
| ω−6 | Arachidonic acid | C20:4 | Δ$^{5,8,11,14}$ | CH$_3$(CH$_2$)$_4$CH=CHCH$_2$CH=CHCH$_2$CH=CHCH$_2$ CH=CH(CH$_2$)$_3$COOH | cis | |
| ω−6 | Docosatetraenoic acid | C22:4 | Δ$^{7,10,13,16}$ | CH$_3$(CH$_2$)$_4$CH=CHCH$_2$CH=CHCH$_2$CH=CHCH$_2$ CH=CH(CH$_2$)$_5$COOH | cis | |
| ω−7 | Palmitoleic acid | C16:1 | Δ$^9$ | CH$_3$(CH$_2$)$_5$CH=CH(CH$_2$)$_7$COOH | cis | macadamia nuts |
| ω−7 | Vaccenic acid | C18:1 | Δ$^{11}$ | CH$_3$(CH$_2$)$_5$CH=CH(CH$_2$)$_9$COOH | trans | dairy products such as milk, butter, and yogurt |
| ω−7 | Paullinic acid | C20:1 | Δ$^{13}$ | CH$_3$(CH$_2$)$_5$CH=CH(CH$_2$)$_{11}$COOH | cis | guarana |
| ω−9 | Oleic acid | C18:1 | Δ$^9$ | CH$_3$(CH$_2$)$_7$CH=CH(CH$_2$)$_7$COOH | cis | olive oil, pecan oil, canola oil |
| ω−9 | Elaidic acid | C18:1 | Δ$^9$ | CH$_3$(CH$_2$)$_7$CH=CH(CH$_2$)$_7$COOH | trans | hydrogenated vegetable oil |
| ω−9 | Gondoic acid | C20:1 | Δ$^{11}$ | CH$_3$(CH$_2$)$_7$CH=CH(CH$_2$)$_9$COOH | cis | jojoba oil (edible but non-caloric and non-digestible) |
| ω−9 | Erucic acid | C22:1 | Δ$^{13}$ | CH$_3$(CH$_2$)$_7$CH=CH(CH$_2$)$_{11}$COOH | cis | wallflower seed, mustard oil |
| ω−9 | Nervonic acid | C24:1 | Δ$^{15}$ | CH$_3$(CH$_2$)$_7$CH=CH(CH$_2$)$_{13}$COOH | cis | King salmon, flaxseed, sockeye salmon, sesame seed, macadamia nuts |
| ω−9 | Mead acid | C20:3 | Δ$^{5,8,11}$ | CH$_3$(CH$_2$)$_7$CH=CHCH$_2$CH=CHCH$_2$CH=CH(CH$_2$)$_3$COOH | cis | cartilage |

## Fatty acid molecular species
### Mono-unsaturated fatty acid

The following fatty acids have one unsaturated bond.

#### Crotonic acid

Crotonic acid has 4 carbons, is included in croton oil, and is a trans-2-mono-unsaturated fatty acid. C$_3$H$_5$ CO$_2$H, IUPAC organization name (E)-but-2-enoic acid, trans-but-2-enoic acid, numerical representation 4:1, n-1, molecular weight 86.09, melting point 72–74 °C, boiling point 180–181 °C, specific gravity 1.027. CAS registry number 107-93-7.

#### Myristoleic

Myristoleic acid has 14 carbons, is found in whale blubber, and is a cis-9-monounsaturated fatty acid. C$_{13}$H$_{25}$CO$_2$H, IUPAC organization name (Z)-tetradec-9-enoic acid, numerical representation 14:1, n-5, molecular weight 226.36, melting point of −4.5 – −4 °C. CAS Registry Number 544-64-9.

#### Palmitoleic acid

Palmitoleic acid has 16 carbons, is found in cod liver oil, sardine oil, and herring oil, and is a cis-9-monounsaturated fatty acid. C$_{15}$H$_{29}$CO$_2$H, IUPAC organization name (Z)-hexadec-9-enoic acid, n-7, numerical representation of 16:1, molecular weight 254.41, melting point 5 °C, specific gravity 0.894. CAS Registry Number 373-49-9.

#### Sapienic acid

Sapienic acid has 16 carbons, is found in the skin, and is a cis-6-mono-unsaturated fatty acid. C$_{15}$H$_{29}$CO$_2$H, IUPAC organization name (Z)-6-Hexadecenoic acid, n-10, numerical expression 16:1, molecular weight 254.41. CAS Registry Number 17004-51-2.

#### Oleic acid

Oleic acid has 18 carbons, is found in most animal fats and olive oil, and is a cis-9-monounsaturated fatty acid. C$_{17}$H$_{33}$CO$_2$H, IUPAC organization name (Z)-octadec-9-enoic acid, numerical representation 18:1 (9), n-9, molecular weight 282.46, melting point 13.4 °C, specific gravity 0.891. CAS Registry Number 112-80-1.

#### Elaidic acid

Elaidic acid has 18 carbons and is a trans-9-mono-unsaturated fatty acid. It is also a trans isomer of oleic acid. C$_{17}$H$_{33}$CO$_2$H, IUPAC organization name (E)-octadec-9-enoic acid, numerical representation 18:1 (9), n-9, molecular weight 282.46, melting point 43–45 °C. CAS Registry Number 112-79-8.

#### Vaccenic acid

Vaccenic acid has 18 carbons, is found in beef tallow, mutton, and butter, and is a trans-11-mono-unsaturated fatty acid. C$_{17}$H$_{33}$CO$_2$H, IUPAC organization name (E)-octadec-11-enoic acid, numerical representation 18:1 (11) n-7, molecular weight 282.46. CAS Registry Number 506-17-2.

#### Gadoleic acid

Gadoleic acid has 20 carbons, is found in cod liver oil and other marine animal oils, and is a cis-9-mono-unsaturated fatty acid. C$_{19}$H$_{37}$CO$_2$H, IUPAC organization name (Z)-icos-9-enoic acid, numerical representation 20:1 (9), n-11, molecular weight 310.51. CAS Registry Number 29204-02-2.

#### Eicosenoic acid

Eicosenoic acid has 20 carbons, is found in a wide variety of plant oils, and is a cis-11-mono-unsaturated fatty acid. C$_{19}$H$_{37}$CO$_2$H, IUPAC organization name (Z)-icos-11-enoic acid, numerical representation 20:1 (11), n-9, molecular weight 310.51. CAS Registry Number 5561-99-9.

#### Erucic acid

Erucic acid has 22 carbons, is found in rapeseed oil and mustard oil, and is a cis-13-monounsaturated is a fatty acid. C$_{21}$H$_{41}$CO$_2$H, IUPAC organization name (Z)-docos-13-enoic acid, numerical representation 22:1, n-9, molecular weight 338.57, melting point 33–35 °C. CAS Registry Number 112-86-7.

#### Nervonic acid

Nervonic acid has 24 carbons, is found in brain glycolipids (Nervon) and sphingomyelin, and is a cis-15-mono-unsaturated fatty acid. C$_{23}$H$_{45}$CO$_2$H, IUPAC organization name (Z)-tetracos-15-enoic acid, numerical representation 24:1, n-9, molecular weight 366.62, melting point 42–43 °C. CAS Registry Number 506-37-6.

### Di-unsaturated fatty acid

The following fatty acids have two unsaturated bonds.

#### Linoleic acid

Linoleic acid has 18 carbons, is contained in many vegetable oils, particularly semi-drying oils, and is a cis-9-cis-12-di-unsaturated fatty acid. C$_{17}$H$_{31}$CO$_2$H, IUPAC organization name (9Z, 12Z)-octadeca-9,12-dienoic acid, numerical representation 18:2 (9,12), n-6, molecular weight 280.45, melting point −5 °C, specific gravity 0.902. CAS Registry Number 60-33-3. There are isomers of linoleic acid with double bonds separated by one single bond. They are named conjugated linoleic acids.

#### Eicosadienoic acid

Eicosadienoic acid (eicosadienoic's) has 20 carbons and is a cis-11-cis-14-di-unsaturated fatty acid. C$_{19}$H$_{35}$CO$_2$H, IUPAC organization name (11Z, 14Z)-icosa-11,14-dienoic acid, numerical representation 20:2 (11,14), n-6, molecular weight 308.50.

#### Docosadienoic acid

Docosadienoic acid (docosadienoic's) has 22 carbons and is a cis-13-cis-16-di-unsaturated fatty acid. C$_{21}$H$_{39}$CO$_2$H, IUPAC organization name (13Z, 16Z)-docosa-13,16-dienoic acid, numerical representation 22:2 (13,16), n-6, molecular weight 336.55. CAS Registry Number 7370-49-2.

### Tri-unsaturated fatty acids

The following fatty acids have three unsaturated bonds.

#### Linolenic acid

α-Linolenic acid (alpha-linolenic's) has 18 carbons, is found in linseed oil and drying oil, and is a 9,12,15-tri-unsaturated fatty acid. C$_{17}$H$_{29}$CO$_2$H, IUPAC organization name (9Z, 12Z, 15Z)-octadeca-9,12,15-trienoic acid, numerical representation 18:3 (9,12,15), n-3, molecular weight 278.43, melting point −11 °C, specific gravity 0.914. CAS Registry Number 463-40-1.
γ-Linolenic acid (gamma-linolenic's) has 18 carbons, is the structural isomer of α-linolenic acid. IUPAC organization name (6Z, 9Z, 12Z)-octadeca-6,9,12-trienoic acid, numerical representation 18:3 (6,9,12), n-6. CAS Registry Number 506-26-3.

#### Pinolenic acid

Pinolenic acid (pinolenic's) has 18 carbons, is found in pine nuts, and is a 5,9,12-triunsaturated fatty acid. C$_{17}$H$_{29}$CO$_2$H, IUPAC organization name (5Z, 9Z, 12Z)-octadeca-5,9,12-trienoic acid, numerical representation 18:3 (5,9,12), n-6, molecular weight 278.43. CAS Registry Number 16833-54-8.

#### Eleostearic acid

α-Eleostearic acid (alpha-eleostearic's) has 18 carbons, is found in Kiri drying oil, and is a 9,11,13-triunsaturated fatty acid. C$_{17}$H$_{29}$CO$_2$H, IUPAC organization name (9Z, 11E, 13E)-octadeca-9,11,13-trienoic acid, numerical representation 18:3 (9,11,13), n-5, molecular weight 278.43.
β-Eleostearic acid (beta-eleostearic's, beta-eleostearic acid) is a geometric isomer of α-eleostearic acid. IUPAC organization name (9E, 11E, 13E)-octadeca-9,11,13-trienoic acid, numerical representation 18:3 (9,11,13), n-5.
α- and β-Eleostearic acids are cis–trans isomers. Other cis–trans isomers of eleostearic acid are:
Catalpic acid (9E, 11E, 13Z) Punicic acid (9Z, 11E, 13Z).

#### Mead acid

Mead acid (Mead's) has 20 carbons, is a 5,8,11-tri-unsaturated fatty acid. C$_{19}$H$_{33}$CO$_2$H, IUPAC organization name (5Z, 8Z, 11Z)-icosa-5,8,11-trienoic acid, numerical representation 20:3 (5,8,11), n-9, molecular weight 306.48. CAS Registry Number 20590-32-3.

#### Dihomo-γ-linolenic acid

Dihomo-γ-linolenic acid (dihomo-gamma-linolenic's, dihomo-gamma-linolenic acid, DGLA) has 20 carbons, and is an 8,11,14-tri-unsaturated fatty acid. C$_{19}$H$_{33}$CO$_2$H, IUPAC organization name (8Z, 11Z, 14Z)-icosa-8,11,14-trienoic acid, numerical representation 20:3 (8,11,14), n-6, molecular weight 306.48. CAS Registry Number 1783-84-2.

#### Eicosatrienoic acid

Eicosatrienoic acid (eicosatrienoic's, eicosatrienoic acid) has 20 carbons and is an 11,14,17- tri unsaturated fatty acid. C$_{19}$H$_{33}$CO$_2$H, IUPAC organization name (11Z, 14Z, 17Z)-icosa-11,14,17-trienoic acid, numerical representation 20:3 (11,14,17), n-3, molecular weight 306.48.

### Tetra-unsaturated fatty acids

The following fatty acids have four unsaturated bonds.

#### Stearidonic acid

Stearidonic acid (stearidonic's) has 18 carbons, is found in sardine oil and herring oil, and is a 6,9,12,15-tetraunsaturated fatty acid. C$_{17}$H$_{27}$CO$_2$H, IUPAC organization name (6Z, 9Z, 12Z, 15Z)-octadeca-6,9,12,15-tetraenoic acid, numerical representation 18:4 (6,9,12,15), n-3, molecular weight 276.41. CAS Registry Number 20290-75-9.

#### Arachidonic acid

Arachidonic acid (arachidonic's) has 20 carbons, is present in animal visceral fat (brain, liver, kidney, lung, spleen), and is a 5,8,11,14-tetra-unsaturated fatty acid. C$_{19}$H$_{31}$CO$_2$H, IUPAC organization name (5Z, 8Z, 11Z, 14Z)-icosa-5,8,11,14-tetraenoic acid, numerical representation 20:4 (5,8,11,14), n-6, molecular weight 304.47, boiling point 169–171 °C. CAS Registry Number 506-32-1.
In signal transduction, arachidonic acid is produced through decomposition of the phospholipid cell membrane. This gives rise to the arachidonic acid cascade, a metabolic pathway that yields lipid mediator compounds such as prostaglandins, thromboxanes and leukotrienes. This pathway has attracted study for its key role in inflammatory diseases such as asthma.

#### Eicosatetraenoic acid

Eicosatetraenoic acid (eicosatetraenoic's) has 20 carbons and is an 8,11,14,17-tetraunsaturated fatty acid. C$_{19}$H$_{31}$CO$_2$H, IUPAC organization name (8Z, 11Z, 14Z, 17Z)-icosa-8,11,14,17-tetraenoic acid, numerical representation 20:4 (8,11,14,17), n-3, molecular weight 304.47.

#### Adrenic acid

Adrenic acid (adrenic'sd) has 22 carbons and is a 7,10,13,16-tetra-unsaturated fatty acid. C$_{21}$H$_{35}$CO$_2$H, IUPAC organization name (7Z, 10Z, 13Z, 16Z)-docosa-7,10,13,16-tetraenoic acid, numerical representation 22:4 (7,10,13,16), n-6, molecular weight 332.52. CAS Registry Number 28874-58-0.

### Penta-unsaturated fatty acids

The following fatty acids have five unsaturated bonds.

#### Bosseopentaenoic acid

Bosseopentaenoic acid (Boseopentaen's), has 20 carbons and is a 5,8,10,12,14-pentaunsaturated fatty acid. C$_{17}$H$_{25}$CO$_2$H, IUPAC organization name (5Z, 8Z, 10E, 12E, 14Z)-eicosa-5,8,10,12,14-pentaenoic acid, numerical representation 20:5 (5,8,10,12,14), n-6, molecular weight 302.46 g·mol−1.

#### Eicosapentaenoic acid

Eicosapentaenoic acid (EPA) has 20 carbons, is found in fish oil, is a pentaunsaturated fatty acid. It is one of the essential fatty acids. The recommendation of ingesting fish oil supplements during pregnancy is said to help increase the cognitive ability at 6 months, but mercury concentration in fish products offsets the effect. In patients with hyperlipidemia and obstructive artery disease it can help lower triglycerides and also has an anti-platelet effect similar to other anti-platelet agents. It has also been shown to help in secondary prevention of ischemic heart disease as shown with the JELIS test.
C$_{19}$H$_{29}$CO$_2$H, IUPAC organization name (5Z, 8Z, 11Z, 14Z, 17Z)-icosa-5,8,11,14,17-pentaenoic acid, numerical representation of 20:5 (5,8,11,14,17), n-3, molecular weight 302.45, melting point −54 – −53 °C, specific gravity 0.943. CAS Registry Number 10417-94-4.

#### Ozubondo acid

Ozubondo acid (Ozubondo's, Osbond acid), has 22 carbons, is a 4,7,10,13,16- pentaunsaturated fatty acid. C$_{21}$H$_{33}$CO$_2$H, IUPAC organization name (4Z, 7Z, 10Z, 13Z, 16Z)-docosa-4,7,10,13,16-pentaenoic acid, numerical representation 22:5 (4,7,10,13,16), n-6, molecular weight 330.50. CAS Registry Number 25182-74-5

#### Sardine acid

Sardine acid (clupanodonic acid) has 22 carbons, is found in sardine oil and herring oil, is a 7,10,13,16,19- pentaunsaturated fatty acid. C$_{21}$H$_{33}$CO$_2$H, IUPAC organization name (7Z, 10Z, 13Z, 16Z, 19Z)-docosa-7,10,13,16,19-pentaenoic acid, numerical representation 22:5 (7,10,13,16,19), n-3, molecular weight 330.50.

#### Tetracosapentaenoic acid

Tetracosapentaenoic acid has 24 carbons, is a 9,12,15,18,21-penta unsaturated fatty acid. C$_{23}$H$_{37}$CO$_2$H, IUPAC organization name (9Z, 12Z, 15Z, 18Z, 21Z)-tetracosa-9,12,15,18,21-pentaenoic acid, numerical representation 24:5 (9,12,15,18,21), n-3, molecular weight 358.56.

### Hexa-unsaturated fatty acids

The following fatty acids have six unsaturated bonds.

#### Cervonic acid

Cervonic acid (or docosahexaenoic acid) has 22 carbons, is found in fish oil, is a 4,7,10,13,16,19-hexa unsaturated fatty acid. In the human body its generation depends on consumption of omega 3 essential fatty acids (e.g., ALA or EPA), but the conversion process is inefficient. C$_{21}$H$_{31}$CO$_2$H, IUPAC organization name (4Z, 7Z, 10Z, 13Z, 16Z, 19Z)-docosa-4,7,10,13,16,19-hexaenoic acid, numerical representation 22:6 (4,7,10,13,16,19), n-3, molecular weight 328.49, melting point −44 °C, specific gravity 0.950. CAS Registry Number 6217-54-5.

#### Herring acid

Herring acid (Herring's, Nisinic acid) is a 6,9,12,15,18,21-hexa unsaturated fatty acid with 24 carbon atoms. C$_{23}$H$_{35}$CO$_2$H, IUPAC organization name (6Z, 9Z, 12Z, 15Z, 18Z, 21Z)-tetracosa-6,9,12,15,18,21-hexaenoic acid, numerical representation 24:6 (6,9,12,15,18,21), n-3, molecular weight 356.54.