Undecylenic acid

Preparation

Undecylenic acid is prepared by pyrolysis of ricinoleic acid, which is derived from castor oil. Specifically, the methyl ester of ricinoleic acid is cracked to yield both undecylenic acid and heptanal. The process is conducted at 500–600 °C in the presence of steam. The methyl ester is then hydrolyzed.

:[[Image:Pyrolyse von Ricinolsäuremethylester.svg|class=skin-invert-image|center|400px|Pyrolyse von Ricinolsäuremethylester]]

General commercial uses

Undecylenic acid is converted to 11-aminoundecanoic acid on an industrial scale. This aminocarboxylic acid is the precursor to Nylon-11.

Undecylenic acid is reduced to undecylene aldehyde, which is valued in perfumery. The acid is first converted to the acid chloride, which allows selective reduction.

Medical uses

Undecylenic acid and its esters such as glyceryl undecylenate are an active ingredient in medications for skin infections, and to relieve itching, burning, and irritation associated with skin problems. For example, it is used against fungal skin infections, such as athlete's foot, ringworm, tinea cruris,

When used for tinea cruris, it can result in extreme burning. In some case studies of tinea versicolor, pain and burning result from fungicide application. In a review of placebo-controlled trials, undecenoic acid was deemed efficacious, alongside prescription azoles (e.g., clotrimazole) and allylamines (e.g., terbinafine).

Undecylenic acid is also a precursor to active ingredients in antidandruff shampoos and antimicrobial powders.

In terms of the mechanism underlying its antifungal effects against Candida albicans, undecylenic acid inhibits morphogenesis. In a study on denture liners, undecylenic acid in the liners was found to inhibit conversion of yeast to the hyphal form (which are associated with active infection), via inhibition of fatty acid biosynthesis. The mechanism of action and effectiveness in fatty acid-type antifungals is dependent on the number of carbon atoms in the chain, with efficacy increasing with the number of atoms in the chain. The optimum seems to be 11 carbon atoms as with longer fatty acids the effect is limited by a lower solubility in water which results in a reduced bioavailability.

U.S. FDA approval

Undecylenic acid is approved by the U.S. FDA for topical route and is listed in the Code of Federal Regulations.

Research uses

Undecylenic acid has been used as a linking molecule, because it is a bifunctional compound. Specifically it is an α,ω- (terminally functionalized) bifunctional agent. For instance, the title compound has been used to prepare silicon-based biosensors, linking silicon transducer surfaces to the terminal double bond of undecylenic acid (forming an Si-C bond), leaving the carboxylic acid groups available for conjugation of biomolecules (e.g., proteins).

Literature

• NN: Undecylenic acid. Monograph. In: Altern. Med. Rev. 7(1), 2002, S. 68–70, PMID 11896747.
• N. McLain, R. Ascanio, C. Baker et al.: Undecylenic acid inhibits morphogenesis of Candida albicans. In: Antimicrob Agents Chemother 44(10), 2000, S. 2873–2875, PMID 10991877, .

References

References

1. 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
2. A. Chauvel, G. Lefebvre. (1989). "Petrochemical Processes: Technical and Economic Characteristics".
3. Christian Kohlpaintner, Markus Schulte, Jürgen Falbe, Peter Lappe, Jürgen Weber. "Aldehydes, Aliphatic".
4. (1 May 2016). "Antifungal effects of undecylenic acid on the biofilm formation of Candida albicans". International Journal of Clinical Pharmacology and Therapeutics.
5. (18 July 2007). "Topical treatments for fungal infections of the skin and nails of the foot.". The Cochrane Database of Systematic Reviews.
6. (July 2015). "United States International Trade Commission Memorandum". USITC.
7. [https://web.archive.org/web/20050109075027/http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?CFRPart=333&showFR=1 Publisher FDA] CFR Title 21, Volume 5, Chapter 1, Subchapter D, Part 333, Subpart C, Sec. (§333.210)
8. (2008). "Amidation of Monolayers on Silicon in Physiological Buffers: A Quantitative IR Study". J. Phys. Chem. C.