Lauric acid

Lauric acid
Identifiers
CAS number 143-07-7 Y
PubChem 3893
ChEMBL CHEMBL108766 N
Properties
Molecular formula C12H24O2
Molar mass 200.31776
Appearance white powder
Odor slight odor of bay oil
Density 0.880 g/cm3
Melting point

43.2 °C[1]

Boiling point

298.9 °C

Solubility in water 0.006 g/100 mL (20 °C)
Refractive index (nD) 1.423
Viscosity 7.30 mPa·s at 323 K
Hazards
NFPA 704
1
1
1
Flash point ≥ 110 °C
Related compounds
Related compounds Glyceryl laurate
 N (verify) (what is: Y/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Lauric acid (systematically: dodecanoic acid), the saturated fatty acid with a 12-carbon atom chain, is a white, powdery solid with a faint odor of bay oil or soap.

Contents

Occurrence

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),[2][3] 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%).[2]

Properties

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.[3]

Niche uses

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 (43.9 °C). Its cryoscopic constant is 3.9 K/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.[4]

Potential medicinal properties

Lauric acid has been claimed to have antimicrobial properties.[5][6][7][8]

Lauric acid has been found to increase total cholesterol the most of all fatty acids. But most of the increase is attributable to an increase in high-density lipoprotein (HDL) "good" cholesterol. As a result, lauric acid has "a more favorable effect on total:HDL cholesterol than any other fatty acid, either saturated or unsaturated";[9] a lower total/HDL cholesterol ratio suggests a decrease in atherosclerotic risk.[10]

References

  1. ^ Lide, D. R., ed (2005). CRC Handbook of Chemistry and Physics (86th ed.). Boca Raton (FL): CRC Press. ISBN 0-8493-0486-5. 
  2. ^ 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. http://iupac.org/publications/pac/73/4/0685/. 
  3. ^ 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
  4. ^ "Using Freezing Point Depression to find Molecular Weight". University of California, Irvine. 2010-04-12. https://eee.uci.edu/programs/gchem/02MANfrzptdep.pdf. 
  5. ^ Hoffman KL, Han IY, Dawson PL (2001). "Antimicrobial effects of corn zein films impregnated with nisin, lauric acid, and EDTA". J. Food Prot. 64 (6): 885–9. PMID 11403145. 
  6. ^ Ouattar B, Simard RE, Piett G, Bégin A, Holley RA (2000). "Inhibition of surface spoilage bacteria in processed meats by application of antimicrobial films prepared with chitosan". Int. J. Food Microbiol. 62 (1–2): 139–48. doi:10.1016/S0168-1605(00)00407-4. PMID 11139014. 
  7. ^ PL Dawson, GD Carl, JC Acton, and IY Han (1 May 2002). "Effect of lauric acid and nisin-impregnated soy-based films on the growth of Listeria monocytogenes on turkey bologna" (Free full text). Poultry Science 81 (5): 721–726. PMID 12033424. http://ps.fass.org/cgi/content/abstract/81/5/721. 
  8. ^ Alexey Ruzin and Richard P. Novick (May 2000). "Equivalence of Lauric Acid and Glycerol Monolaurate as Inhibitors of Signal Transduction in Staphylococcus aureus" (Free full text). J Bacteriol 182 (9): 2668–2671. doi:10.1128/JB.182.9.2668-2671.2000. PMC 111339. PMID 10762277. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=111339. 
  9. ^ 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. http://www.ajcn.org/content/77/5/1146.full?ijkey=846a72387ebc0d82545acd5442a0c3a9e9fc3566. 
  10. ^ 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 9783540225690.

Appendix: occurrence of lauric acid in various foods

Further reading