Thymol (also known as 2-isopropyl-5-methylphenol, IPMP) is a natural monoterpenephenol derivative of cymene, C10H14O, isomeric with carvacrol, found in oil of thyme, and extracted from Thymus vulgaris (common thyme) and various other kinds of plants as a white crystalline substance of a pleasant aromaticodor and strong antisepticproperties. Thymol also provides the distinctive, strong flavor of the culinary herbthyme, also produced from T. vulgaris.
Thymol is part of a naturally occurring class of compounds known as biocides, with strong antimicrobial attributes when used alone or with other biocides such as carvacrol. In addition, naturally occurring biocidal agents such as Thymol can reduce bacterial resistance to common drugs such as penicillin. Numerous studies have demonstrated the antimicrobial effects of Thymol, ranging from inducing antibiotic susceptibility in drug-resistant pathogens to powerful antioxidant properties. Research demonstrates that naturally occurring biocides such as Thymol and carvacrol reduce bacterial resistance to antibiotics through a synergistic effect, and Thymol has been shown to be an effective fungicide,particularly against fluconazole-resistant strains. This is especially relevant given that opportunistic Candida fungal infections can cause severe systemic infections in immuno compromised patients, and current treatments are highly toxic, often result in drug-resistant Candida strains, and have low efficacy. Compounds in the essential oils of one type of oregano have demonstrated antimutagenic effects, and in particular carvacrol (isomeric with Thymol) and Thymol were demonstrated to have a strong antimutagenic effect. In addition, there is evidence that Thymol has antitumor properties. Though the exact mechanism is unknown, some evidence suggests Thymol affects at least some of its biocidal properties by membrane disruption.
Thymol has been shown to act as a positive allosteric modulator of GABAAin vitro.Thymol is chemically related to the aesthetic propof
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.
Thymol has antimicrobial activity because of its phenolic structure, and has shown antibacterial activity against bacterial strains including Aeromoans hydrophila and Staphylococcus aureus. This antibacterial activity is caused by inhibiting growth and lactate production, and by decreasing cellular glucose uptake.Thymol has been used in alcohol solutions and in dusting powders for the treatment of tinea or ringworm infections, and was used in the United States to treat hookworm infections. It is also used as a preservative in halothane, an anaesthetic, and as an antiseptic in mouthwash. When used to reduce plaque and gingivitis, Thymol has been found to be more effective when used in combination with chlorhexidine than when used purely by itself. Thymol is also the active antiseptic ingredient in some toothpaste, such as Euthymol.
The antifungal nature of Thymol is caused by Thymol's ability to alter the hyphal morphology and cause hyphal aggregates, resulting in reduced hyphal diameters and lyses of hyphal wall. Additionally, Thymol is lipophilic, enabling it to interact with the cell membrane of fungus cells, altering cell membrane permeability permitting the loss of macromolecules.
Recent medical research on rats concludes that "Thyme extract had relaxing effects on organs possessing β2-receptors (uterus and trachea).
In a 1994 report released by five major cigarette companies, Thymol was listed as one of 599 additives to cigarettes.
Thymol has been used to successfully control Varroa mites and prevent fermentation and the growth of mould in bee colonies, methods developed by beekeeper R.O.B. Manley.
Thymol is also used as a rapidly degrading, non-persisting pesticide.
Derivatives of Thymol and carvacrol with increased antimicrobial activities have been developed. The preparation of methacrylic and p-styrenesulfonic acid esters of Thymol could lead to less toxic macromolecular biocides, which can be attached to a polymeric backbone.
A minor use of Thymol is in book and paper conservation: Paper with mould damage can be sealed in bags with Thymol crystals to kill fungal spores. However, this practice is not currently recommended due to apparent accelerated degradation suffered by these objects.