Lauric acid

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Lauric acid
Skeletal formula of lauric acid
Lauric-acid-3D-balls.png
Identifiers
CAS number 143-07-7 YesY
PubChem 3893
ChemSpider 3756 N
EC number 205-582-1
ChEBI CHEBI:30805 N
ChEMBL CHEMBL108766 N
Jmol-3D images Image 1
Properties
Molecular formula C12H24O2
Molar mass 200.32 g mol−1
Appearance White powder
Odor Slight odor of bay oil
Density 1.007 g/cm3 (24 °C)[1]
0.8744 g/cm3 (41.5 °C)[2]
0.8679 g/cm3 (50 °C)[3]
Melting point 43.8 °C (110.8 °F; 316.9 K)[3]
Boiling point 297.9 °C (568.2 °F; 571.0 K)
282.5 °C (540.5 °F; 555.6 K)
at 512 mmHg[1]
225.1 °C (437.2 °F; 498.2 K)
at 100 mmHg[3][6]
Solubility in water 37 mg/L (0 °C)
55 mg/L (20 °C)
63 mg/L (30 °C)
72 mg/L (45 °C)
83 mg/L (100 °C)[4]
Solubility Soluble in alcohols, (C2H5)2O, phenyls, haloalkanes, acetates[4]
Solubility in methanol 12.7 g/100 g (0 °C)
120 g/100 g (20 °C)
2250 g/100 g (40 °C)[4]
Solubility in acetone 8.95 g/100 g (0 °C)
60.5 g/100 g (20 °C)
1590 g/100 g (40 °C)[4]
Solubility in ethyl acetate 9.4 g/100 g (0 °C)
52 g/100 g (20 °C)
1250 g/100 g (40 °C)[4]
Solubility in toluene 15.3 g/100 g (0 °C)
97 g/100 g (20 °C)
1410 g/100 g (40 °C)[4]
log P 4.6[5]
Vapor pressure 2.13·10-6 kPa (25 °C)[5]
0.42 kPa (150 °C)[6]
6.67 kPa (210 °C)[7]
Acidity (pKa) 5.3 (20 °C)[5]
Thermal conductivity 0.442 W/m·K (solid)[2]
0.1921 W/m·K (72.5 °C)
0.1748 W/m·K (106 °C)[1]
Refractive index (nD) 1.423 (70 °C)[1]
1.4183 (82 °C)[3]
Viscosity 6.88 cP (50 °C)
5.37 cP (60 °C)[2]
Structure
Crystal structure Monoclinic (α-form)[8]
Triclinic, aP228 (γ-form)[9]
Space group P21/a, No. 14 (α-form)[8]
P1, No. 2 (γ-form)[9]
Point group 2/m (α-form)[8]
1 (γ-form)[9]
Lattice constant a = 9.524 Å, b = 4.965 Å, c = 35.39 Å (α-form)[8]
Lattice constant α = 90°, β = 129.22°, γ = 90°
Thermochemistry
Specific
heat capacity
C
404.28 J/mol·K[6]
Std enthalpy of
formation
ΔfHo298
−775.6 kJ/mol[5]
Std enthalpy of
combustion
ΔcHo298
7377 kJ/mol
7425.8 kJ/mol (292 K)[6]
Hazards
GHS pictograms The flame pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)The corrosion pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)
GHS signal word Danger
GHS hazard statements H412[7]
GHS precautionary statements P273[7]
EU classification Irritant Xi
R-phrases R36/38
S-phrases S24/25, S26, S36/39
NFPA 704
Flammability code 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g., canola oil Health code 1: Exposure would cause irritation but only minor residual injury. E.g., turpentine Reactivity code 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g., calcium Special hazards (white): no codeNFPA 704 four-colored diamond
Flash point > 113 °C (235 °F; 386 K)[7]
Related compounds
Related compounds Glyceryl laurate
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 N (verify) (what is: YesY/N?)
Infobox references

Lauric acid or systematically dodecanoic acid, the saturated fatty acid with a 12-carbon atom chain, thus falling into the medium chain fatty acids, is a white, powdery solid with a faint odor of bay oil or soap.

Occurrence[edit]

Laurel oil contains lauric acid.

Lauric acid, as a component of triglycerides, comprises about half of the fatty acid content in coconut oil, laurel oil, and in palm kernel oil (not to be confused with palm oil),[10][11] Otherwise it is relatively uncommon. It is also found in human breast milk (6.2% of total fat), cow's milk (2.9%), and goat's milk (3.1%).[10]

In various plants[edit]

Properties[edit]

Like many other fatty acids, lauric acid is inexpensive, has a long shelf-life, and is non-toxic and safe to handle. It is mainly used for the production of soaps and cosmetics. For these purposes, lauric acid is neutralized with sodium hydroxide to give sodium laurate, which is a soap. Most commonly, sodium laurate is obtained by saponification of various oils, such as coconut oil. These precursors give mixtures of sodium laurate and other soaps.[11]

Niche uses[edit]

In the laboratory, lauric acid is often used to investigate the molar mass of an unknown substance via the freezing-point depression. Lauric acid is convenient because its melting point when pure is relatively high (43.8 °C). Its cryoscopic constant is 3.9 °C·kg/mol. By melting lauric acid with the unknown substance, allowing it to cool, and recording the temperature at which the mixture freezes, the molar mass of the unknown compound may be determined.[12]

Potential medicinal properties[edit]

In vitro experiments have suggested that some fatty acids including lauric acid could be a useful component in a treatment for acne, but no clinical trials have yet been conducted to evaluate this potential benefit in humans.[13][14]

Lauric acid increases total serum cholesterol the most of any fatty acid. But most of the increase is attributable to an increase in high-density lipoprotein (HDL) (the "good" blood cholesterol). As a result, lauric acid has been characterized as having "a more favorable effect on total HDL cholesterol than any other fatty acid, either saturated or unsaturated".[15] In general, a lower total/HDL serum cholesterol ratio correlates with a decrease in atherosclerotic risk.[16] Nonetheless, an extensive meta-analysis on foods affecting the total/LDL serum cholesterol ratio found in 2003 that the net effects of lauric acid on coronary artery disease outcomes remained uncertain.[17]

References[edit]

  1. ^ a b c d G., Chuah T.; D., Rozanna; A., Salmiah; Y., Thomas Choong S.; M., Sa'ari (2006). "Fatty Acids used as Phase Change Materials (PCMs) for Thermal Energy Storage in Building Material Applications". University Putra Malaysia. Retrieved 2014-06-22. 
  2. ^ a b c Mezaki, Reiji; Mochizuki, Masafumi; Ogawa, Kohei (2000). Engineering Data on Mixing (1st ed.). Elsevier Science B.V. p. 278. ISBN 0-444-82802-8. 
  3. ^ a b c d Lide, David R., ed. (2009). CRC Handbook of Chemistry and Physics (90th ed.). Boca Raton, Florida: CRC Press. ISBN 978-1-4200-9084-0. 
  4. ^ a b c d e f Seidell, Atherton; Linke, William F. (1952). Solubilities of Inorganic and Organic Compounds (3rd ed.). New York: D. Van Nostrand Company. pp. 742–743. 
  5. ^ a b c d CID 3893 from PubChem
  6. ^ a b c d Dodecanoic acid in Linstrom, P.J.; Mallard, W.G. (eds.) NIST Chemistry WebBook, NIST Standard Reference Database Number 69. National Institute of Standards and Technology, Gaithersburg MD. http://webbook.nist.gov (retrieved 2014-06-14)
  7. ^ a b c d Sigma-Aldrich Co., Lauric acid. Retrieved on 2014-06-14.
  8. ^ a b c d Vand, V.; Morley, W. M.; Lomer, T. R. (1951). "The crystal sructure of lauric acid". Acta Crystallographica 4 (4): 324. doi:10.1107/S0365110X51001069.  edit
  9. ^ a b c Sydow, Erik von (1956). "On the Structure of the Crystal Form A of Lauric Acid". http://actachemscand.org 10. Acta Chemica Scandinavica. Retrieved 2014-06-14. 
  10. ^ a b Beare-Rogers, J.; Dieffenbacher, A.; Holm, J.V. (2001). "Lexicon of lipid nutrition (IUPAC Technical Report)". Pure and Applied Chemistry 73 (4): 685–744. doi:10.1351/pac200173040685. 
  11. ^ a b David J. Anneken, Sabine Both, Ralf Christoph, Georg Fieg, Udo Steinberner, Alfred Westfechtel "Fatty Acids" in Ullmann's Encyclopedia of Industrial Chemistry 2006, Wiley-VCH, Weinheim. doi:10.1002/14356007.a10_245.pub2
  12. ^ "Using Freezing Point Depression to find Molecular Weight". University of California, Irvine. 2010-04-12. [dead link]
  13. ^ Nakatsuji, T; Kao, MC; Fang, JY; Zouboulis, CC; Zhang, L; Gallo, RL; Huang, CM (2009). "Antimicrobial Property of Lauric Acid Against Propionibacterium acnes: Its Therapeutic Potential for Inflammatory Acne Vulgaris". The Journal of investigative dermatology 129 (10): 2480–8. doi:10.1038/jid.2009.93. PMC 2772209. PMID 19387482. 
  14. ^ Yang, D; Pornpattananangkul, D; Nakatsuji, T; Chan, M; Carson, D; Huang, CM; Zhang, L (2009). "The Antimicrobial Activity of Liposomal Lauric Acids Against Propionibacterium acnes". Biomaterials 30 (30): 6035–40. doi:10.1016/j.biomaterials.2009.07.033. PMC 2735618. PMID 19665786. 
  15. ^ Mensink RP, Zock PL, Kester ADM, Katan MB (May 2003). "Effects of dietary fatty acids and carbohydrates on the ratio of serum total to HDL cholesterol and on serum lipids and apolipoproteins: a meta-analysis of 60 controlled trials". American Journal of Clinical Nutrition 77 (5): 1146–1155. ISSN 0002-9165. PMID 12716665. 
  16. ^ Thijssen, M.A. and R.P. Mensink. (2005). Fatty Acids and Atherosclerotic Risk. In Arnold von Eckardstein (Ed.) Atherosclerosis: Diet and Drugs. Springer. pp. 171–172. ISBN 978-3-540-22569-0.
  17. ^ Effects of dietary fatty acids and carbohydrates on the ratio of serum total to HDL cholesterol and on serum lipids and apolipoproteins: a meta-analysis of 60 controlled trials

Further reading[edit]

External links[edit]