Myristic acid structure, properties, obtaining, uses

1961
Philip Kelley

The myristic acid is a long-chain acidic organic compound whose chemical formula is C14H28ORtwo. It is also known as tetradecanoic acid. It is a straight chain monocarboxylic saturated fatty acid, with a skeleton of 14 carbon atoms and with a carboxyl group -COOH at one end.

It is widely distributed in plant and animal fats and oils. Its abundant presence in palm oil, coconut oil, nutmeg oil and butter stands out.. 

Myristic acid. Author: Marilú Stea.

Myristic acid is part of biochemical processes that occur in the organism of living beings, especially those related to the cell membrane. It is also found, for example, in the membranes of human cells..

For this reason, its application has been studied against cancerous tumors, bacterial and fungal infections, as well as an agent to keep some foods free of bacteria..

Although ingested in large quantities can be harmful to the cardiovascular system, its ingestion in very small doses is beneficial for the balance of fats in humans.

It has some uses in the soap and cosmetic industry or also as a raw material for food flavors and aromas.

Article index

  • 1 Structure
  • 2 Nomenclature
  • 3 Properties
    • 3.1 Physical state
    • 3.2 Molecular weight
    • 3.3 Melting point
    • 3.4 Boiling point
    • 3.5 Specific weight
    • 3.6 Refractive index
    • 3.7 Dissociation constant
    • 3.8 Solubility
    • 3.9 Biochemical properties
  • 4 Obtaining
  • 5 Therapeutic uses
    • 5.1 Against cancer tumors
    • 5.2 Against bacterial and fungal infections
    • 5.3 Protective effects against deficient feeding in some nutrients
    • 5.4 Beneficial health effects in low amounts
  • 6 Potential use as a preservative additive in food
  • 7 Use as raw material to synthesize a corrosion inhibitor
  • 8 Various applications
  • 9 References

Structure

Myristic acid has a linear chain of 14 carbons which is saturated, that is, it does not have double bonds, and the carbon at one of the ends belongs to a carboxyl group -COOH, formed by a carbonyl group -C = O and a hydroxyl group -OH.

It is said to be a fatty acid because it has a long hydrocarbon chain, which gives it an oily appearance. The chain is extended linearly but in a zigzag shape due to the tetrahedral bond angles of the carbon..

Structure of myristic acid. Edgar181 [Public domain]. Source: Wikipedia Commons.

Nomenclature

- Myristic acid

- Tetradecanoic acid

Properties

Physical state

Oily crystalline solid

Molecular weight

228.37 g / mol

Melting point

53.9 ºC

Boiling point

250.5 ºC at 100 mm Hg

Specific weight

0.8622 g / cm3 at 54 ºC / 4 ºC

Refractive index

1.7423 at 70 ºC

Dissociation constant

pKa = 4.90 (means that it is weaker than for example acetic acid)

Solubility

In water: 22 mg / L at 30 ºC.

Soluble in ethanol, methanol, petroleum ether, acetone, chloroform. Very soluble in benzene.

Slightly soluble in ethyl ether.

Biochemical properties

In biochemical processes, myristic acid is added to cell proteins through an amide bond. Modification of the protein occurs through a glycine residue. This mechanism is called myristylation..

The enzyme responsible for myristylation is called N-myristyltransferase. This process is essential for the growth of cells and the signaling of certain proteins..

Obtaining

It can be obtained by fractional distillation of coconut oil and other vegetable oils such as palm kernel oil.

Therapeutic uses

Against cancerous tumors

Some researchers found that myristic acid has antitumor activity on Ehrlich cancer in mice. They estimated that the effect may be derived from the fact that it acts as a "detergent" on the tumor cell membrane and, therefore, alters or destroys it..

Other scientists found that myristic acid delayed melanoma outbreak and mortality in mice. It is thought that the effect is probably due to the fact that this acid promotes endocytosis (the process by which the cell incorporates particles, molecules or other external cells within itself) and also the intracellular reaction at the membrane level..

This means that myristic acid can induce the activation of cells involved in the body's defense, such as macrophages, increasing phagocytosis..

Macrophage Carolina Coelho [CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0)]. Source: Wikipedia Commons.

Against bacterial and fungal infections

Myristic acid exerts a protective effect against laboratory-induced infection of Salmonella typhimurium in mice as it increases the natural defense exerted by macrophages.

Salmonella typhimurium. Photo: Volker Brinkmann, Max Planck Institute for Infection Biology, Berlin, Germany [CC BY 2.5 (https://creativecommons.org/licenses/by/2.5)]. Source: Wikipedia Commons.

The effect of myristic acid has been studied against Candida albicans, an opportunistic fungus that can infect humans and has resistance to various antifungal drugs.

It was found that myristic acid strongly inhibits the biofilm of the fungus and the formation of its hyphae (network of filaments that make up the structure of the fungus).

The ability of myristic acid to react and neutralize certain proteins involved in various attack sequences of the fungus, such as the synthesis and metabolism of certain key compounds, multi-resistance to drugs and oxidative stress, has led researchers to propose it for the treatment of Candida albicans.

The mechanism of action of myristic acid leads to the fact that the fungus cannot generate resistance and makes it effective although the Candida albicans already have resistance to other antifungal drugs.

Protective effects against poor diet in some nutrients

In tests carried out on rat specimens, myristic acid has been found to protect against kidney damage (damage to the kidneys), such as tubular necrosis, caused by a diet deficient in agents that provide methyl groups, such as some of the vitamins in the B Group.

Beneficial health effects in low amounts

Myristic acid has a disadvantage or negative point: it is one of the saturated fatty acids that exerts the greatest atherogenic effect.

That means it allows fatty deposits to appear on the walls of the arteries, leading to their calcification and loss of elasticity..

Arterial wall with calcification of atherosclerotic plaque. Author: Kwz ~ commonswiki. Source: Wikipedia Commons.

However, some researchers have shown in experiences with monkeys that when myristic acid is ingested in small amounts, it has a beneficial lipid effect and favors the production of docosahexenoic acid, which is useful for fat balance..

For this reason, they concluded that the supply of small amounts of myristic acid with the diet helps to maintain various physiological reactions and regulations in a healthy way..

These investigations were confirmed by other studies in humans in which it was concluded that the intake of myristic acid in 1.8% of the total calories ingested is associated with a lower risk of cardiovascular disease.

Potential use as a preservative additive in food

Myristic acid proved to be a potential food preservative, since when added to dairy foods it inhibited the growth of Listeria monocytogenes, a pathogenic microorganism with immunoresistance to many drugs.

It was confirmed that it had an influence on the cell death of the pathogen and inhibited growth as it changed the morphology and structure of the membrane of said bacteria, accelerating cell death. Myristic acid bound to cellular DNA and induced changes in its conformation.

Culture of Lysteria monocytogenes. James.folsom [Public domain]. Source: Wikipedia Commons.

Use as a raw material to synthesize a corrosion inhibitor

An environmentally friendly corrosion inhibitor for industrial applications was synthesized starting from myristic acid and diethyleneamine..

It was effective in inhibiting the corrosion of low carbon steel in a 15% hydrochloric acid (HCl) solution. The inhibition efficiency reaches 93%.

The researchers found that there is a strong bond between the corrosion inhibitor molecules and the surface of the steel, and suggest that the protection mechanism involves the barrier effect of the long hydrocarbon chain of myristic acid..

Various applications

Myristic acid is used as a raw material to synthesize flavor-, aroma- and perfume-generating esters. In addition, its derivative myristic aldehyde is used as a condiment in various foods.

It is also used in the formulation of soaps, shaving creams, cosmetics and the like, where it acts, for example, as an emulsifier and foam controller..

It is used in the preparation of food grade additives, such as those used in cheese, milk, jellies, puddings, meat products, non-alcoholic beverages and soft candies, among others..

Also used in machine lubricants and coatings for anodized aluminum.

References

  1. U.S. National Library of Medicine. (2019). Myristic acid. Recovered from: pubchem.ncbi.nlm.nih.gov.
  2. Chen, X., et al. (2019). Antimicrobial potential of myristic acid against Listeria monocytogenes in milk. The Journal of Antibiotics. Springer Nature. February 2019. Recovered from europepmc.org.
  3. Solomon, M.M., et al. (2019). Myristic acid based imidazoline derivative as effective corrosion inhibitor for steel in 15% HCl medium. Journal of Colloid and Interface Science. 551 (2019) 47-60. Recovered from sciencedirect.com.
  4. Vaysse-Boué, C. et al. (2007). Moderate Dietary Intake of Myristic and Alpha-Linolenic Acids Increases Lecithin-Cholesterol Acyltransferase Activity in Humans. Lipids (2007) 42: 717-722. Recovered from aocs.onlinelibrary.wiley.com.
  5. Dabadie, H., et al. (2005). Moderate intake of myristic acid in sn-2 position has beneficial lipidic effects and enhances DHA of cholesteryl esters in an interventional study. Journal of Nutritional Biochemistry 16 (2005) 375-382. Recovered from sciencedirect.com.
  6. Prasath, K.G., et al. (2019). Proteomic analysis uncovers the modulation of ergosterol, sphingolipid and oxidative stress pathway by myristic acid impeding biofilm and virulence in Candida albicans. Journal of Proteomics. August 2019. Abstract retrieved from europepmc.org.
  7. Monserrat, A.J., et al. (2000). Protective effect of myristic acid on renal necrosis occurring in rats fed a methyl deficient diet. Research in Experimental Medicine. 199 (2000), pp. 195-206. Recovered from iris.unito.it.
  8. Galdiero, F., et al. (1994). Beneficial effects of myristic, stearic or oleic acid as part of liposomes on experimental infection and antitumor effect in a murine model. Life Science, vol. 55, No. 7, pp. 499-509, 1994. Recovered from aocs.onlinelibrary.wiley.com.
  9. Nishikawa, Y., et al. (1976). Chemical and Biochemical Studies on Carbohydrate Esters. II. Antitumor Activity of Saturated Fatty Acids and Their Ester Derivatives against Ehrlich Ascites Carcinoma. Chem. Pharm. Bull. 24 (3) 387-393 (1976). Recovered from scholar.google.co.ve.
  10. Linder, M.E. (2010). Volume 1. N-myristoylation. In Handbook of Cell Signaling (Second Edition). Recovered from sciencedirect.com.

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