Undecylenic acid structure, properties, synthesis, uses

4162
Abraham McLaughlin

The undecylenic acid is an organic compound whose chemical formula is CelevenHtwentyORtwo. It is also known as 10-undecenoic acid and is an unsaturated fatty acid with a double bond between the tenth and eleventh carbon.

It is obtained from castor oil, that is, from castor oil. It is found naturally in some plants, especially the berries of the black elderberry bush. If undecylenic acid is heated in the presence of air it produces a dicarboxylic acid (that is, a compound with two carboxyl groups -COOH) and oxidized polymeric material..

Undecylenic acid. Author: Marilú Stea.

If heated in the absence of air, it polymerizes, that is, it generates compounds with two or more units stuck together repeatedly. It has been generally used as an antifungal agent and for the treatment of skin problems, such as eczema, ringworm, and other skin conditions. It acts as a fungistatic. It is used in topical treatment.

Because it has two opposite functional groups, it acts as a binding molecule in various applications, such as in the production of polymers, to increase the biosensitivity of certain materials and to promote the transport of anticancer drugs..

Article index

  • 1 Structure
  • 2 Nomenclature
  • 3 Physical properties
    • 3.1 Physical state
    • 3.2 Molecular weight
    • 3.3 Melting point
    • 3.4 Boiling point
    • 3.5 Density
    • 3.6 Solubility
  • 4 Chemical properties
    • 4.1 Heating in the presence of oxygen
    • 4.2 Heating in the absence of oxygen
    • 4.3 Toxicity
  • 5 Synthesis
  • 6 Uses
    • 6.1 In the treatment of skin diseases
    • 6.2 In synthesis of other organic molecules
    • 6.3 In obtaining polymers
    • 6.4 In nanomedicine against cancer
    • 6.5 In novel materials
  • 7 References

Structure

It has a saturated chain with a double bond (C = C) and a carboxylic group (-COOH) at opposite ends of the molecule.

The following is the structure of the undecylenic acid molecule, where each vertex corresponds to a -CH unittwo-, the left end has a double bond and at the right end there is a -COOH.

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

Nomenclature

- Undecylenic acid

- 10-undecenoic acid

- 10,11-undecylenic acid

- Undec-10-enoic acid

Physical properties

Physical state

Solid (crystals) or liquid depending on the ambient temperature.

Molecular weight

184.27 g / mol

Melting point

24.5 ºC

Boiling point

275 ° C, decomposes at 295 ° C

Density

0.907 g / cm3

Solubility

Insoluble in water. Soluble in alcohol, ether and chloroform

Chemical properties

Heating in the presence of oxygen

If undecylenic acid is heated to 80 ° C under a continuous stream of CO-free airtwo, There are several reactions, among which are:

1) Double bond breaking with formation of dicarboxylic acid.

2) Formation of epoxides by adding oxygen at the place of the double bond.

3) Formation of peroxides.

4) Reactions of the above with the original undecylenic acid molecule.

As a consequence of these reactions, the following products are obtained: sebacic acid (which is a dicarboxylic acid), 10,11-dihydroxyundecanoic acid (produced by the breakdown of an epoxide) and polymeric material (formed by aldol condensation of ketone oxidation products).

The epoxides and peroxides formed react rapidly to give other oxidation products.

Heating in the absence of oxygen

When 10-undecenoic acid is exposed to temperatures of 250-325 ° C, under a nitrogen atmosphere it forms dimers, trimers and larger polymers. The amount of polymers increases with increasing reaction time.

Toxicity

Although the information consulted is not conclusive in terms of toxicity in humans, undecylenic acid has been shown to present acute and chronic toxicity in animals for laboratory tests that ingested it.

The lethal dose for 50% of the specimens (L.D.fifty) is 8.15 g / Kg. Chronicity studies indicated that when the food contains 2.5% undecylenic acid, the growth of the animals is inhibited.

Synthesis

It can be obtained from castor oil (also called castor oil), since 90% of the fatty acids in castor oil is ricinoleic acid. Heating the latter under vacuum conditions, until its pyrolysis, undecylenic acid is obtained.

Obtaining undecylenic acid by pyrolysis of ricinoleic acid from castor oil. Author: Marilú Stea

Applications

In the treatment of skin diseases

Undecylenic acid is beneficial in the treatment of dermatophytosis such as tinea pedis, tinea cruris and tinea corporis.

Tinea corporis is a superficial infection of dermatophyte fungi. The form that is acquired by person-person contact is generally caused by T. rubrum. Acquired by contact with pets such as cats and dogs is caused by Microsporum canis.

When the fungal infection is in the feet, it is called tinea pedis, colloquially called athlete's foot. Zinc undecylenate is used as a topical antifungal agent for this condition. Relieves the stinging, burning and irritation of that disease.

Healthy feet. Author: Xavalox. Source: Pixabay.

In addition, undecylenic acid emulsions have been effective in inhibiting filamentation and growth of Candida albicans, an infection-causing fungus.

According to sources consulted, undecylenic acid has not been successful for the treatment of psoriasis.

In synthesis of other organic molecules

Undecylenic acid has two functional groups: the carboxylic group -COOH and the C = C double bond, which is why it is said to have a bifunctional property.

Due to its bifunctional property it is used for the conjugation or union of other biomolecules such as proteins, as it acts as a binding molecule.

One of its known uses is in the preparation of boldenone, which is an ester of undecylenic acid. Boldenone has veterinary applications and, although it is not medically approved for use in people, there are those who use it as an anabolic steroid.

In obtaining polymers

Undecylenic acid has been used successfully for the preparation of polyurethanes.

Polyurethanes prepared with undecylenic acid exhibit good thermal and mechanical properties and excellent hydrolytic resistance due to their high hydrophobicity (they do not show weight loss or decrease in molecular weight when remaining in aqueous solution at 60 ºC for 6 months).

These characteristics make them suitable for long-term applications and in moisture-sensitive environments..

Table varnished with polyurethane resin. Bagoto [CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0)]. Source: Wikipedia Commons.

In nanomedicine against cancer

Undecylenic acid has been used in the preparation of porous silicon nanoparticles to which it has been attached by heat treatment..

These particles are useful for deep penetration into tumors and the delivery of anticancer drugs therein. Undecylenic acid contributes to greater stability of silicon nanoparticles in aqueous medium.

Porous silicon nanoparticles. Manninog [CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0)]. Source: Wikipedia Commons.

The nanoparticle thus constructed has the ability to generate apoptosis (death) of several cancer cells one after another, as a domino effect..

In novel materials

Undecylenic acid has been used to optimize the biosensitivity properties of nanocrystalline diamond.

Boron-doped nanocrystalline diamond has various properties, such as biocompatibility, thermal conductivity, hardness, and is chemically inert, making it suitable for a wide variety of applications such as electronic devices, biosensitive materials, and cell cultures..

To improve biosensitivity, the surface of diamond nanocrystals must be modified with biocompatible functional groups, such as carboxylic acids, amines or alcohols, and thus achieve the coupling or fixation of biomolecules.

Photochemical coupling with undecylenic acid is a convenient method of introducing carboxylic groups onto diamond..

When this procedure is carried out especially without protecting the main group, a higher density of COOH groups is obtained on the surface of the diamond..

This gives it a greater possibility of coupling biomolecules, optimizing their biosensitivity properties..

References

  1. Lligadas, Gerard et al. (2012). Oleic Acid and Undecylenic Acid as Platform Chemicals for Thermoplastic Polyurethanes. Biobased Monomers, Polymers, and Materials. Chapter 17, 2012, 269-280. Recovered from pubs.acs.org.
  2. DalNogare, S. and Bricker, C.E. (1950). Behavior of 10,11-undecylenic acid on air-oxidation at 80 ºC. Journal of Organic Chemistry 1950, 15, 6, 1299-1308. Recovered from pubs.acs.org.
  3. Newell, G.W. et al. (1949). Studies of the acute and chronic toxicity of undecylenic acid. Journal of Investigative Dermatology. Vol.13, Issue 3, September 1949. Recovered from sciencedirect.
  4. Ross, J. et al. (1945) The Polymerization of Undecylenic Acid. Journal of the American Chemical Society. 1945, August, Vol. 67. Recovered from pubs.acs.org.
  5. Denk, Larry MD. (2007). Tinea Corporis. In Pediatric Clinical Advisor (Second Edition). Recovered from sciencedirect.com
  6. Zhong, Yu Lin, et al. (2007). Optimizing Biosensing Properties on Undecylenic Acid-Functionalized Diamond. Langmuir 2007, 23, 5824-5830. Recovered from pubs.acs.org.
  7. Yong, Tuying et al. (2016). Domino-Like Intercellular Delivery of Undecylenic Acid-Conjugated Porous Silicon Nanoparticles for Deep Tumor Penetration. ACS Applied Materials & Interfaces 2016, 8, 41 27611-27621. Recovered from pubs.acs.org.

Yet No Comments