Thymol

Chembox new
ImageFile = Thymol2.svg
ImageSize = 150
ImageName = Thymol
IUPACName = 5-methyl-2-(isopropyl)phenol
Section1 = Chembox Identifiers
CASNo = 89-83-8
SMILES = CC1=CC(O)=C(C(C)C)C=C1
Section2 = Chembox Properties
Formula = C₁₀H₁₄O
MolarMass = 150.22 g/mol
Density = 0.96 g/cm³
MeltingPt = 49-51 °C
BoilingPt = 232 °C

Thymol is a monoterpene phenol derivative of cymene, C₁₀H₁₄OH, isomeric with carvacrol, found in oil of thyme, and extracted as a white crystalline substance of a pleasant aromatic odor and strong antiseptic properties. It is also called "hydroxy cymene". [Webster's 1913 dictionary)]

History

The Ancient Egyptians used thymol and carvacrol in the form of a preparation from the thyme plant, because of their ability to conserve mummies. Thymol and carvacrol are now known to kill bacteria and fungi, having made thyme well suited for such purposes.

The crystalline substance thymol was discovered by Caspar Neumann in 1719 and synthesized in pure form in the year 1842 by von M. Lallemand characterized through elementary chemical analysis. Using this, he was able to discover the correct ratio of carbon, hydrogen, and oxygen that make up thymol molecules. Friedrich Ferdinand Runge also studied the chemistry of this substance. Alain Thozet und M. Perrin first published the crystral structure analysis with the exact determination of the structural atoms.

Uses

Thymol has been found to be useful in controlling varroa mites in bee colonies. [http://news.bbc.co.uk/2/hi/science/nature/4780034.stm Almond farmers seek healthy bees] ] A minor use is in bookbinding: before rebinding, books with mould damage can be sealed in bags with thymol crystals to kill fungal spores. It is also used as a preservative in halothane, an anaesthetic, and as an antiseptic in mouthwash.

The Bee Balms "(Monarda fistulosa and Monarda didyma)" are natural sources of thymol, a primary active ingredient in modern commercial mouthwash formulas. The Blackfeet Indians recognized this plant's strong antiseptic action, and used poultices of the plant for skin infections and minor wounds. A tea made from the plant was also used to treat mouth and throat infections caused by dental caries and gingivitis. [Edible and Medicinal Plants of the West, Gregory L. Tilford, ISBN 0-87842-359-1]

Recent medical research on rats concludes that "Thyme extract had relaxing effects on organs possessing β₂-receptors (uterus and trachea)." [Cite journal| issue = 7| pages = 629–635| last = Wienkötter| first = N.| coauthors = F. Begrow, U. Kinzinger, D. Schierstedt, E.J. Verspohl| title = The Effect of Thyme Extract on β₂-Receptors and Mucociliary Clearance| journal = Planta Medica| date = 2007| doi = 10.1055/s-2007-981535| volume = 73]

In a 1994 report released by five top cigarette companies, thymol was listed as one of 599 additives to cigarettes. [http://quitsmoking.about.com/cs/nicotineinhaler/a/cigingredients.htm List of 599 Cigarette additives] ] It is said to be added to improve the flavor of cigarettes, but as mentioned above, it relaxes the trachea.

There is also evidence supporting the belief that thymol when applied two to three times daily, can eliminate certain kinds of fungal infections that affect finger nails and toe nails in humans.Fact|date=March 2008 Regular application to the affected nail over periods approximating three months, has been shown to eliminate the affliction by effectively preventing further progress;Fact|date=March 2008 by simply cutting the nail as one normally would, all infected material is eventually eliminated.

Biological activity

Thymol has GABAnergic activity, [Cite journal| issue = 140| pages = 1363–1372| last = Priestley| first = Caroline M.| coauthors = E. Williamson, K. Wafford, and D. Sattelle| title = Thymol, a constituent of thyme essential oil, is a positive allosteric modulator of human GABAA receptors and a homo-oligomeric GABA receptor from Drosophila melanogaster| journal = British Journal of Pharmacology| date = 2003| doi = 10.1038/sj.bjp.0705542.| doi_brokendate = 2008-06-21] a mechanism of action similar to other depressants such as secobarbital, methaqualone and diazepam. It bears close similarity to the widely used anaesthetic propofol (2,6-diisopropylphenol). Because it is less potent, thymol could potentially be abused like the more common depressants. Propofol is extremely dangerous because of its very steep dose-response curve and high potency. It is commonly abused among anesthesiologists and nurses, many times causing death. [Iwersen-Bergmann S, Rösner P, Kühnau HC, Junge M, Schmoldt A. Death after excessive propofol abuse. International Journal of Legal Medicine. 2001;114(4-5):248-51.] [Kranioti EF, Mavroforou A, Mylonakis P, Michalodimitrakis M. Lethal self administration of propofol (Diprivan). A case report and review of the literature. Forensic Science International. 2007 Mar 22;167(1):56-8. Epub 2006 Jan 23.] Because of thymol's lowered potency and safer dose-response curve, it could feasibly be abused as a legal depressant. Because propofol is not scheduled, thymol is neither a controlled substance nor a controlled substance analogue in the US and the UK. Because of its widespread availability in food products, it is unlikely to ever come under control.

ee also

*GABA
*Depressants

References

External links

* [http://www.3dchem.com/molecules.asp?ID=158# What is Thymol?]
* [http://www.nailfunguscures.com/downloads/Published%20Paper%20-%20Invitro%20Study%20of%20Homeopathic%20Remedy%20forToe%20Nail%20Fungus.pdf Activity of Monoterpenes Against Toe Nail Fungi]