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Linoleic acid



Linoleic acid
IUPAC name cis, cis-9,12-octadecadienoic acid.[1]
Identifiers
CAS number 60-33-3
SMILES CCCCCC=CCC=CCCCCCCCC(=O)O
Properties
Molecular formula C18H32O2
Molar mass 280.44548(1724) g/mol
Density 0.9 g/cm3
Melting point

-5 °C

Boiling point

°C

Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)

Infobox 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 since removing the omega-6 double bond produces oleic acid.

Additional recommended knowledge

Contents

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]

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. 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] Noni seed oil is abundant in linoleic acid, and a number of beauty products contain noni seed oil.[citation needed]

Foods

Oils and foods that contain linoleic acid include safflower oil (78%), poppy seed oil (70%), walnut oil, grass fed cow milk, olive oil, palm oil, sunflower oil, soybean, lard, coconut oil, egg yolks (16%), spirulina, peanut oil, okra, rice bran oil, wheat germ oil, grape seed oil, macadamia oil, pistachio oil, sesame oil.

See also

References

  1. ^ Beare-Rogers (2001). IUPAC Lexicon of Lipid Nutrition (pdf). Retrieved on 2006-02-22.
  2. ^ 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.
  3. ^ 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.
  4. ^ (1993) "Plant oils: Topical application and anti-inflammatory effects (croton oil test)". Dermatol. Monatsschr 179.
  5. ^ (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.
  6. ^ (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.
 
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Linoleic_acid". A list of authors is available in Wikipedia.
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