Thymol

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Thymol
Thymol
Thymol3D.png
IUPAC name
Identifiers
CAS number 89-83-8 Yes check.svgY
ATCvet code QP53AX22
SMILES
Properties
Molecular formula C10H14O
Molar mass 150.22 g/mol
Density 0.96 g/cm3
Melting point

49-51 °C

Boiling point

232 °C

 Yes check.svgY (what is this?)  (verify)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Thymol (also known as 2-isopropyl-5-methylphenol), (IPMP) is a monoterpene phenol derivative of cymene, C10H14O, isomeric with carvacrol, found in oil of thyme, and extracted as a white crystalline substance of a pleasant aromatic odor and strong antiseptic properties. Thymol is only slightly soluble in water at neutral pH, but it is extremely soluble in alcohols and other organic solvents. It is also soluble in strongly alkaline aqueous solutions due to deprotonation of the phenol. It is also called "Isopropyl-m-cresol" and "hydroxy cymene".[1]

Contents

[edit] History

The Ancient Egyptians used thymol and carvacrol in the form of a preparation from the thyme plant (a member of the mint family), because of their ability to preserve 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 and M. Perrin first published the crystal structure analysis with the exact determination of the structural atoms.

[edit] Uses

Thymol has been used to successfully control varroa mites and prevent fermentation and the growth of mould in bee colonies.[2]. A minor use is in bookbinding: before rebinding, books with mold damage can be sealed in bags with thymol crystals to kill fungal spores. Thymol has been used in alcohol solutions and in dusting powders for the treatment of tinea (ringworm) infections. Thymol was used to treat hookworm infections in the US.[3] It is also used as a preservative in halothane, an anaesthetic, and as an antiseptic in mouthwash. It is the active antiseptic ingredient in the toothpaste Euthymol.

The Bee Balms (Monarda fistulosa and Monarda didyma) are natural sources of thymol, a primary active ingredient in modern commercial mouthwash formulas. The Blackfeet Native Americans 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.[4]

Recent medical research on rats concludes that "Thyme extract had relaxing effects on organs possessing β2-receptors (uterus and trachea)."[5]

In a 1994 report released by five top cigarette companies, thymol was listed as one of 599 additives to cigarettes.[6] 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.[citation needed] Regular application to the affected nail over periods approximating three months has been shown to eliminate the affliction by effectively preventing further progress;[citation needed] by simply cutting the nail as one normally would, all infected material is eventually eliminated.

[edit] Biological activity

Thymol has GABAergic activity,[7] via a mechanism of action similar to the anaesthetic propofol (2,6-diisopropylphenol). Thymol is neither a controlled substance nor a controlled substance analogue in the US and the UK.

[edit] List of plants that contain the chemical

[edit] Toxicology

Thymol is dangerous to the environment and toxic to aquatic organisms; and, may cause long term adverse effects in the aquatic environment. It is also being investigated as a mutagen. The theory of its mutagenic effect is further supported by the performance of the related phenol.

[edit] Compendial status

[edit] See also

[edit] Notes and references

  1. ^ Webster's 1913 dictionary)
  2. ^ Almond farmers seek healthy bees
  3. ^ The Rural School and Hookworm Disease. Jno A Ferrell, 1914 http://books.google.com/books?id=omYAAAAAYAAJ&dq=THE+RURAL+SCHOOL+AND+hookworm+disease&printsec=frontcover&source=bl&ots=MzB2Qc83MN&sig=XuzEewv27ty90cJ3IxS8fhyh0A4&hl=en&ei=KHKUSsOVKY_QsQOmnNnZBg&sa=X&oi=book_result&ct=result&resnum=1#v=onepage&q=&f=true
  4. ^ Edible and Medicinal Plants of the West, Gregory L. Tilford, ISBN 0-87842-359-1
  5. ^ Wienkötter, N.; F. Begrow, U. Kinzinger, D. Schierstedt, E.J. Verspohl (2007). "The Effect of Thyme Extract on β2-Receptors and Mucociliary Clearance". Planta Medica 73 (7): 629–635. doi:10.1055/s-2007-981535. 
  6. ^ List of 599 Cigarette additives
  7. ^ Priestley, Caroline M.; E. Williamson, K. Wafford, and D. Sattelle (2003). "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". British Journal of Pharmacology 140 (140): 1363–1372. doi:10.1038/sj.bjp.0705542. 
  8. ^ a b Goodner, K.L. et al. (2006). "Aromatic profiles of Thymus hyemalis and Spanish T. vulgaris essential oils by GC–MS/GC–O". Industrial Crops and Products 24 (3): 264–268. doi:10.1016/j.indcrop.2006.06.006. 
  9. ^ Lee, Seung-Joo et al. (2005). "Identification of volatile components in basil (Ocimum basilicum L.) and thyme leaves (Thymus vulgaris L.) and their antioxidant properties". Food Chemistry 91 (1): 131–137. doi:10.1016/j.foodchem.2004.05.056. 
  10. ^ Moldão-Martins, M. et al. (2000). "Supercritical CO2 extraction of Thymus zygis L. subsp. sylvestris aroma". The Journal of Supercritical Fluids 18 (1): 25–34. doi:10.1016/S0896-8446(00)00047-4. 
  11. ^ The British Pharmacopoeia Secretariat (2009). "Index, BP 2009". http://www.pharmacopoeia.co.uk/pdf/2009_index.pdf. Retrieved 5 July 2009. 

[edit] External links