Linoleic acid
From Wikipedia, the free encyclopedia
| Linoleic acid | |
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| The chemical strucuture of linoleic acid showing physiological numbering (red) and chemical numbering (blue) conventions. |
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| Chemical name | cis, cis-9,12-octadecadienoic acid.[1] |
| Chemical formula | C18H32O2 |
| Structural formula | CH3-(CH2)4-(CH=CH-CH2)2 -(CH2)6-COOH |
| Molecular mass | 280.44548(1724) g/mol |
| CAS number | 60-33-3 |
| Density | 0.9 g/cm3 |
| Melting point | -5 °C |
| Boiling point | ? °C |
| SMILES | CCCCCC=CCC=CCCCCCCCC(=O)O |
| Disclaimer and references | |
Linoleic acid (LA) is an unsaturated omega-6 fatty acid. It is a colorless liquid. In physiological literature, it is called 18:2(n-6). Chemically, linoleic acid is a carboxylic acid with an 18-carbon chain and two cis double bonds; the first double bond is located at the sixth carbon from the omega end.
The word linoleic comes from the Greek word linon (flax). Oleic means of, relating to, or derived from oil or of or relating to oleic acid.
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[edit] In Physiology
Linoleic acid is a polyunsaturated fatty acid used in the biosynthesis of prostaglandins. It is found in the lipids of cell membranes. It is abundant in many vegetable oils, especially safflower and sunflower oils.
To be fully utilised by the body, LA must be converted into gamma-linolenic acid, a reaction catalysed by the enzyme delta-6-desaturase (D6D).
Linoleic acid is a member of the group of essential fatty acids called omega-6 fatty acids, so called because they are an essential dietary requirement for all mammals. The other group of essential fatty acids is the omega-3 fatty acids, for example Alpha-linolenic acid. Omega-6 deficiency symptoms include dry hair, hair loss, [2] and poor wound healing.[3] It is easy to meet the daily requirement for these fatty acids (even for people consuming low fat diets) and most people get plenty of omega-6 fatty acids in their diet by consuming approximately a tablespoon of polyunsaturated plant oils per day.[citation needed]
[edit] Industrial uses
Linoleic acid is used in making soaps, emulsifiers, and quick-drying oils. Reduction of linoleic acid yields linoleyl alcohol. Linoleic acid has become increasingly popular in the beauty products industry because of its beneficial properties on the skin. For example, the noni seed oil is abundant in linoleic acid, and a line of beauty products from this company contains noni seed oil. Research points to linoleic acid's affective properties when applied topically on the skin, ie. anti-inflammatory, acne reduction, moisture retention properties.[4] [5] [6]
[edit] See also
- Alpha-linolenic acid
- Essential fatty acids
- Essential fatty acid interactions
- Eicosanoids
- Essential nutrients
- Conjugated linoleic acid
[edit] References
- ^ Beare-Rogers (2001). IUPAC Lexicon of Lipid Nutrition (pdf). Retrieved on February 22, 2006.
- ^ Cunnane S, Anderson M (1997). "Pure linoleate deficiency in the rat: influence on growth, accumulation of n-6 polyunsaturates, and (1-14C) linoleate oxidation". J Lipid Res 38 (4): 805-12. PMID 9144095. Retrieved on 2007-01-15.
- ^ Ruthig DJ & Meckling-Gill KA. (1999). "Both (n-3) and (n-6) fatty acids stimulate wound healing in the rat intestinal epithelial cell line, IEC-6". Journal of Nutrition 129 (10): 1791-8. PMID 9144095. Retrieved on 2007-01-15.
- ^ (1993) "Plant oils: Topical application and anti-inflammatory effects (croton oil test)". Dermatol. Monatsschr 179.
- ^ (March 1998) "Digital image analysis of the effect of topically applied linoleic acid on acne microcomedones". Clinical & Experimental Dermatology 23 (2): 56-58. PMID: 9692305.
- ^ (2002) "Impact of topical oils on the skin barrier: possible implications for neonatal health in developing countries". Acta Paediatrica 91 (5): 546-554. Retrieved on 2007-01-12.
