Lauric acid

Lauric acid

Names
IUPAC name Dodecanoic acid
Other names n-Dodecanoic acid, Dodecylic acid, Dodecoic acid, Laurostearic acid, Vulvic acid, 1-Undecanecarboxylic acid, Duodecylic acid, C12:0 (Lipid numbers)
Identifiers
CAS Number	143-07-7
3D model (Jmol)	Interactive image
ChEBI	CHEBI:30805
ChEMBL	ChEMBL108766
ChemSpider	3756
ECHA InfoCard	100.005.075
EC Number	205-582-1
IUPHAR/BPS	5534
PubChem	3893
InChI InChI=1S/C12H24O2/c1-2-3-4-5-6-7-8-9-10-11-12(13)14/h2-11H2,1H3,(H,13,14) Key: POULHZVOKOAJMA-UHFFFAOYSA-N InChI=1/C12H24O2/c1-2-3-4-5-6-7-8-9-10-11-12(13)14/h2-11H2,1H3,(H,13,14) Key: POULHZVOKOAJMA-UHFFFAOYAP
SMILES O=C(O)CCCCCCCCCCC
Properties
Chemical formula	C12H24O2
Molar mass	200.32 g·mol^−1
Appearance	White powder
Odor	Slight odor of bay oil
Density	1.007 g/cm^3 (24 °C)[1] 0.8744 g/cm^3 (41.5 °C)[2] 0.8679 g/cm^3 (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][4]
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)[5]
Solubility	Soluble in alcohols, (C2H5)2O, phenyls, haloalkanes, acetates[5]
Solubility in methanol	12.7 g/100 g (0 °C) 120 g/100 g (20 °C) 2250 g/100 g (40 °C)[5]
Solubility in acetone	8.95 g/100 g (0 °C) 60.5 g/100 g (20 °C) 1590 g/100 g (40 °C)[5]
Solubility in ethyl acetate	9.4 g/100 g (0 °C) 52 g/100 g (20 °C) 1250 g/100 g (40 °C)[5]
Solubility in toluene	15.3 g/100 g (0 °C) 97 g/100 g (20 °C) 1410 g/100 g (40 °C)[5]
log P	4.6[6]
Vapor pressure	2.13·10^−6 kPa (25 °C)[6] 0.42 kPa (150 °C)[4] 6.67 kPa (210 °C)[7]
Acidity (pKa)	5.3 (20 °C)[6]
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] α = 90°, β = 129.22°, γ = 90°
Thermochemistry
Specific heat capacity (C)	404.28 J/mol·K[4]
Std enthalpy of formation (ΔfH^o298)	−775.6 kJ/mol[6]
Std enthalpy of combustion (ΔcH^o298)	7377 kJ/mol 7425.8 kJ/mol (292 K)[4]
Hazards
GHS pictograms
GHS signal word	Danger
GHS hazard statements	H412[7]
GHS precautionary statements	P273[7]
EU classification (DSD)	Xi
R-phrases	R36/38
S-phrases	S24/25, S26, S36/39
NFPA 704	1 1 1
Flash point	> 113 °C (235 °F; 386 K)[7]
Related compounds
Related compounds	Glyceryl laurate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Lauric acid or systematically, dodecanoic acid, is a 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

Laurel oil contains lauric acid.

Lauric acid, as a component of triglycerides, comprises about half of the fatty acid content in coconut milk, coconut oil, laurel oil, and 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

• The palm tree Orbignya phalerata Mart, a species popularly known in Brazil as babassu - 50% in babassu oil.
• Attalea cohune, the cohune palm (also rain tree, American oil palm, corozo palm or manaca palm) - 46.5% in cohune oil.
• Astrocaryum murumuru (Arecaceae) a palm native to the Amazon - 47.5% in "murumuru butter".
• Coconut oil 49%
• Pycnanthus kombo (African nutmeg)
• Virola surinamensis (wild nutmeg) 7.8–11.5%
• Peach palm seed 10.4%
• Betel nut 9%
• Date palm seed 0.56–5.4%
• Macadamia nut 0.072–1.1%
• Plum 0.35–0.38%
• Watermelon seed 0.33%
• Citrullus lanatus (egusi melon)
• Pumpkin flower 205 ppm, pumpkin seed 472 ppm

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.^[11]

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 (43.8 °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

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 more than many other fatty acids. 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 [examined], 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

1. 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" (PDF). University Putra Malaysia. Archived from the original (PDF) on 2014-11-03. Retrieved 2014-06-22.
2. 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. 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. 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)
5. Seidell, Atherton; Linke, William F. (1952). Solubilities of inorganic and organic compounds (3rd ed.). New York: D. Van Nostrand Company. pp. 742–743.
6. CID 3893 from PubChem
7. Sigma-Aldrich Co., Lauric acid. Retrieved on 2014-06-14.
8. Vand, V.; Morley, W. M.; Lomer, T. R. (1951). "The crystal structure of lauric acid". Acta Crystallographica. 4 (4): 324–329. doi:10.1107/S0365110X51001069.
9. Sydow, Erik von (1956). "On the structure of the crystal form A of lauric acid" (PDF). actachemscand.org. Acta Chemica Scandinavica. Retrieved 2014-06-14.
10. 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. 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" (PDF). University of California, Irvine. 2010-04-12.
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 AD, 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

• Berner, Louise A. (1993). Defining the Role of Milkfat in Balanced Diets. In John E. Kinsella (Ed.) Advances in Food and Nutrition Research – Volume 37. Academic Press. pp. 159–166. ISBN 978-0-12-016437-0.
• Kabara, Jon J. (1978). The Pharmacological Effect of Lipids. Champaign IL: American Oil Chemist's Society. ISBN 9991817697.
• Kabara, Jon J. (2008). Fats Are Good for You and Other Secrets – How Saturated Fat and Cholesterol Actually Benefit the Body. North Atlantic Books. ISBN 1-55643-690-4.

External links

• Lauric acid MS Spectrum