Polyunsaturated fatty acid

Polyunsaturated fatty acids (PUFAs) are fatty acids that contain more than one double bond in their backbone. This class includes many important compounds, such as essential fatty acids and those that give drying oils their characteristic property.

Polyunsaturated fatty acids can be classified in various groups by their chemical structure:

Types

Methylene-interrupted polyenes

These fatty acids have 2 or more cis double bonds that are separated from each other by a single methylene bridge (-CH
2
- unit). This form is also sometimes called a divinylmethane pattern.[1]

Methylene- interrupted double bonds
−C−C=C−C−C=C−

The essential fatty acids are all omega-3 and -6 methylene-interrupted fatty acids. See more at Essential fatty acidsNomenclature

Omega-3

Common name Lipid name Chemical name
Omega-3 fatty acids, polyunsaturated
Hexadecatrienoic acid (HTA) 16:3 (n-3) all-cis 7,10,13-hexadecatrienoic acid
Alpha-linolenic acid (ALA) 18:3 (n-3) all-cis-9,12,15-octadecatrienoic acid
Stearidonic acid (SDA) 18:4 (n-3) all-cis-6,9,12,15,-octadecatetraenoic acid
Eicosatrienoic acid (ETE) 20:3 (n-3) all-cis-11,14,17-eicosatrienoic acid
Eicosatetraenoic acid (ETA) 20:4 (n-3) all-cis-8,11,14,17-eicosatetraenoic acid
Eicosapentaenoic acid (EPA, Timnodonic acid) 20:5 (n-3) all-cis-5,8,11,14,17-eicosapentaenoic acid
Heneicosapentaenoic acid (HPA) 21:5 (n-3) all-cis-6,9,12,15,18-heneicosapentaenoic acid
Docosapentaenoic acid (DPA, Clupanodonic acid) 22:5 (n-3) all-cis-7,10,13,16,19-docosapentaenoic acid
Docosahexaenoic acid (DHA, Cervonic acid) 22:6 (n-3) all-cis-4,7,10,13,16,19-docosahexaenoic acid
Tetracosapentaenoic acid 24:5 (n-3) all-cis-9,12,15,18,21-tetracosapentaenoic acid
Tetracosahexaenoic acid (Nisinic acid) 24:6 (n-3) all-cis-6,9,12,15,18,21-tetracosahexaenoic acid

Omega-6

Common name Lipid name Chemical name
Omega-6 fatty acids, polyunsaturated
Linoleic acid 18:2 (n-6) all-cis-9,12-octadecadienoic acid
Gamma-linolenic acid (GLA) 18:3 (n-6) all-cis-6,9,12-octadecatrienoic acid
Eicosadienoic acid 20:2 (n-6) all-cis-11,14-eicosadienoic acid
Dihomo-gamma-linolenic acid (DGLA) 20:3 (n-6) all-cis-8,11,14-eicosatrienoic acid
Arachidonic acid (AA) 20:4 (n-6) all-cis-5,8,11,14-eicosatetraenoic acid
Docosadienoic acid 22:2 (n-6) all-cis-13,16-docosadienoic acid
Adrenic acid 22:4 (n-6) all-cis-7,10,13,16-docosatetraenoic acid
Docosapentaenoic acid (Osbond acid) 22:5 (n-6) all-cis-4,7,10,13,16-docosapentaenoic acid
Tetracosatetraenoic acid 24:4 (n-6) all-cis-9,12,15,18-tetracosatetraenoic acid
Tetracosapentaenoic acid 24:5 (n-6) all-cis-6,9,12,15,18-tetracosapentaenoic acid

Omega-9

Common name Lipid name Chemical name
Omega-9 fatty acids, mono- and polyunsaturated
Oleic acid 18:1 (n-9) cis-9-octadecenoic acid
Eicosenoic acid 20:1 (n-9) cis-11-eicosenoic acid
Mead acid 20:3 (n-9) all-cis-5,8,11-eicosatrienoic acid
Erucic acid 22:1 (n-9) cis-13-docosenoic acid
Nervonic acid 24:1 (n-9) cis-15-tetracosenoic acid
Monounsaturated

Conjugated fatty acids

Conjugated double bonds
-C=C-C=C-
Common name Lipid name Chemical name
Conjugated fatty acids  have two or more conjugated double bonds
Conjugated Linoleic Acids (two conjugated double bonds)
Rumenic acid 18:2 (n-7) 9Z,11E-octadeca-9,11-dienoic acid
  18:2 (n-6) 10E,12Z-octadeca-9,11-dienoic acid
Conjugated Linolenic Acids (three conjugated double bonds)
α-Calendic acid 18:3 (n-6) 8E,10E,12Z-octadecatrienoic acid
β-Calendic acid 18:3 (n-6) 8E,10E,12E-octadecatrienoic acid
Jacaric acid 18:3 (n-6) 8Z,10E,12Z-octadecatrienoic acid
α-Eleostearic acid 18:3 (n-5) 9Z,11E,13E-octadeca-9,11,13-trienoic acid
β-Eleostearic acid 18:3 (n-5) 9E,11E,13E-octadeca-9,11,13-trienoic acid
Catalpic acid 18:3 (n-5) 9Z,11Z,13E-octadeca-9,11,13-trienoic acid
Punicic acid 18:3 (n-5) 9Z,11E,13Z-octadeca-9,11,13-trienoic acid
Other
Rumelenic acid 18:3 (n-3) 9E,11Z,15E-octadeca-9,11,15-trienoic acid
α-Parinaric acid 18:4 (n-3) 9E,11Z,13Z,15E-octadeca-9,11,13,15-tetraenoic acid
β-Parinaric acid 18:4 (n-3) all trans-octadeca-9,11,13,15-tretraenoic acid
Bosseopentaenoic acid 20:5 (n-6) 5Z,8Z,10E,12E,14Z-eicosanoic acid

Other polyunsaturated fatty acids

Common name Lipid name Chemical name
Pinolenic acid 18:3 (n-6) (5Z,9Z,12Z)-octadeca-5,9,12-trienoic acid
Podocarpic acid 20:3 (n-6) (5Z,11Z,14Z)-eicosa-5,11,14-trienoic acid

Function and effects

The biological effects of the ω-3 and ω-6 fatty acids are largely mediated by their mutual interactions, see Essential fatty acid interactions for detail.

See also

References

Citations

  1. Baggott, James (1997). The divinylmethane pattern in fatty acids. Salt Lake City, UT: Knowledge Weavers.

General References

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