Polyunsaturated fat

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 acids—Nomenclature

Omega-3

Omega-3 fatty acids, polyunsaturated
Common name	Lipid name	Chemical name
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

Omega-6 fatty acids, polyunsaturated
Common name	Lipid name	Chemical name
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

Omega-9 fatty acids, mono- and polyunsaturated
Common name	Lipid name	Chemical name
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-

Conjugated fatty acids have two or more conjugated double bonds
Common name	Lipid name	Chemical name
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.

References

Citations

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

General References

Cyberlipid. "Polyenoic Fatty Acids". Retrieved 2007-01-17.

Gunstone, Frank D. "Lipid Glossary 2" (PDF). Archived from the original (PDF) on 2006-08-13. Retrieved 2007-01-17.

Adlof, R. O.; Gunstone, F. D. (2003-09-17). "Common (non-systematic) Names for Fatty Acids". Archived from the original on 2006-12-06. Retrieved 2007-01-24. {{cite web}}: Unknown parameter |lastauthoramp= ignored (|name-list-style= suggested) (help)

Heinz; Roughan, PG (1983). "Similarities and Differences in Lipid Metabolism of Chloroplasts Isolated from 18:3 and 16:3 Plants". Plant Physiol. 72 (2): 273–279. doi:10.1104/pp.72.2.273. PMC 1066223. PMID 16662992.

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

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