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Linoleic acid

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**History and Physiology of Linoleic Acid:**
– F. Sacc isolated linoleic acid in 1844 from linseed oil
– K. Peters discovered two double bonds in 1886
– G. O. Burr found its essential role in human diet in 1930
– T.P. Hilditch determined its chemical structure in 1939
– R. A. Raphael and F. Sondheimer synthesized it in 1950
– Vital for proper health as an essential fatty acid
– Precursor to arachidonic acid in metabolism
– Conversion to arachidonic acid involves several enzymes
Linoleic acid products play roles in human physiology and pathology

**Uses and Dietary Sources of Linoleic Acid:**
– Found in quick-drying oils for oil paints and varnishes
– Acts as a surfactant with a critical micelle concentration
– Popular in beauty products for skin benefits
– Abundant in safflower and corn oil
– Present in soybean oils, sesame, and almonds
– Various oils contain different percentages of linoleic acid
– Examples include safflower oil, evening primrose oil, and grape seed oil
– Chicken fat, egg yolk, and linseed oil also contain linoleic acid

**Occurrence and Synthesis of Linoleic Acid:**
– Cockroaches, ants, and bees release oleic and linoleic acid
– Discourages other roaches from entering the area
– Synthesis discussed in scientific journals
– Research on prostaglandin synthetase organization and mechanism
– Biosynthesis and activity of leukotriene B5 explored
– Modification of tissue profiles by N-3 polyunsaturated fatty acid formulations

**Infant Nutrition and Skin Health with Linoleic Acid:**
– Breast milk-fed infants show higher GLA levels
– Formula-fed infants exhibit increased LA concentrations
– Role of Δ-6-desaturase in fatty acid metabolism
– Effects on acne microcomedones and skin-lightening properties
– Impact of topical oils on the skin barrier
– Evening primrose oil’s benefits for menopause

**Health Implications and Antioxidant Properties of Linoleic Acid:**
– Dietary intake linked to mortality and cardiometabolic effects
– Systematic review on linoleic acid intake and risk of type 2 diabetes
– Relationship between fatty acids and blood cholesterol levels
– Investigating antioxidant properties in oils like pumpkin seed and peach kernel oil
– Analyzing chemical composition of depot fats in chickens and turkeys

Linoleic acid (Wikipedia)

Linoleic acid (LA) is an organic compound with the formula HOOC(CH2)7CH=CHCH2CH=CH(CH2)4CH3. Both alkene groups (−CH=CH−) are cis. It is a fatty acid sometimes denoted 18:2 (n-6) or 18:2 cis-9,12. A linoleate is a salt or ester of this acid.

Linoleic acid
Preferred IUPAC name
(9Z,12Z)-Octadeca-9,12-dienoic acid
Other names
cis,cis-9,12-Octadecadienoic acid
C18:2 (Lipid numbers)
3D model (JSmol)
ECHA InfoCard 100.000.428 Edit this at Wikidata
EC Number
  • 200-470-9
  • InChI=1S/C18H32O2/c1-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16-17-18(19)20/h6-7,9-10H,2-5,8,11-17H2,1H3,(H,19,20)/b7-6-,10-9- checkY
  • InChI=1/C18H32O2/c1-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16-17-18(19)20/h6-7,9-10H,2-5,8,11-17H2,1H3,(H,19,20)/b7-6-,10-9-
Molar mass 280.452 g·mol−1
Appearance Colorless oil
Density 0.9 g/cm3
Melting point −12 °C (10 °F)
−6.9 °C (19.6 °F)
−5 °C (23 °F)
Boiling point 229 °C (444 °F) at 16 mmHg
230 °C (446 °F) at 21 mbar
230 °C (446 °F) at 16 mmHg
0.139 mg/L
Vapor pressure 16 Torr at 229 °C[citation needed]
Acidity (pKa) 4.77 at 25°C
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformFlammability 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
Flash point 112 °C (234 °F)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkY☒N ?)

Linoleic acid is a polyunsaturated, omega-6 fatty acid. It is a colorless liquid that is virtually insoluble in water but soluble in many organic solvents. It typically occurs in nature as a triglyceride (ester of glycerin) rather than as a free fatty acid. It is one of two essential fatty acids for humans, who must obtain it through their diet, and the most essential, because the body uses it as a base to make the others.

The word "linoleic" derives from Latin linum 'flax', and oleum 'oil', reflecting the fact that it was first isolated from linseed oil.

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