|Preferred IUPAC name|
| Systematic IUPAC name |
|Other names |
2-Isopropyl-5-methylphenol, isopropyl-m-cresol, 1-methyl-3-hydroxy-4-isopropylbenzene, 3-methyl-6-isopropylphenol, 5-methyl-2-(1-methylethyl)phenol, 5-methyl-2-isopropyl-1-phenol, 5-methyl-2-isopropylphenol, 6-isopropyl-3-methylphenol, 6-isopropyl-m-cresol, Apiguard, NSC 11215, NSC 47821, NSC 49142, thyme camphor, m-thymol, and p-cymen-3-ol
3D model (JSmol)
CompTox Dashboard (EPA)
|Molar mass||150.221 g·mol−1|
|Melting point||49 to 51 °C (120 to 124 °F; 322 to 324 K)|
|Boiling point||232 °C (450 °F; 505 K)|
|0.9 g/L (20 °C)|
|QP53AX22 ( WHO )|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Thymol (also known as 2-isopropyl-5-methylphenol, IPMP) is a natural monoterpenoid phenol derivative of cymene, C10H14O, isomeric with carvacrol, found in oil of thyme, and extracted from Thymus vulgaris (common thyme), Ajwainand various other kinds of plants as a white crystalline substance of a pleasant aromatic odor and strong antiseptic properties. Thymol also provides the distinctive, strong flavor of the culinary herb thyme, also produced from T. vulgaris.
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 a refractive index of 1.5208 10.59±0.10. Thymol absorbs maximum UV radiation at 274 nm.and an experimental dissociation exponent (pKa) of
Regions lacking natural sources of thymol obtain the compound via total synthesis.Thymol is produced from m-cresol and propene in the gas phase:
The bee balms Monarda fistulosa and Monarda didyma , North American wildflowers, are natural sources of thymol. The Blackfoot Native Americans recognized these plants' strong antiseptic action, and used poultices of the plants for skin infections and minor wounds. A tisane made from them was also used to treat mouth and throat infections caused by dental caries and gingivitis.It was used in ancient Egypt in the process of preservation when they were mummifying corpses.
Thymol was first isolated by the German chemist Caspar Neumann in 1719.In 1853, the French chemist A. Lallemand named thymol and determined its empirical formula. Thymol was first synthesized by the Swedish chemist Oskar Widman in 1882.
An in vitro study found thymol and carvacrol to be highly effective in reducing the minimum inhibitory concentration of several antibiotics against zoonotic pathogens and food spoilage bacteria such as Salmonella typhimurium SGI 1 and Streptococcus pyogenes ermB.In vitro studies have found thymol to be useful as an antifungal against food spoilage and bovine mastitis. Thymol demonstrates in vitro post-antibacterial effect against the test strains E. coli and P. aeruginosa (gram negative), and Staphylococcus aureus and B. cereus (gram positive). This antibacterial activity is caused by inhibiting growth and lactate production, and by decreasing cellular glucose uptake.
Thyme essential oil is useful in preservation of food. The antibacterial properties of thymol, a major part of thyme essential oil, as well as other constituents, are in part associated with their lipophilic character, leading to accumulation in bacterial membranes and subsequent membrane-associated events, such as energy depletion.
The antifungal nature of thymol against some fungi that are pathogenic to plants is due to its ability to alter the hyphal morphology and cause hyphal aggregates, resulting in reduced hyphal diameters and lyses of the hyphal wall.
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. [ citation needed ] 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 toothpastes, such as Johnson & Johnson's Euthymol. Thymol has been used to successfully control varroa mites and prevent fermentation and the growth of mold in bee colonies, methods developed by beekeeper R. O. B. Manley. Thymol is also used as a rapidly degrading, non-persisting pesticide. Thymol can also be used as a medical disinfectant and general purpose disinfectant.People of the Middle East continue to use za'atar, a delicacy made with large amounts of thyme, to reduce and eliminate internal parasites.
In 2009, the U.S. Environmental Protection Agency (EPA) reviewed the research literature on the toxicology and environmental impact of thymol and concluded that "thymol has minimal potential toxicity and poses minimal risk".
Studies have shown that hydrocarbon monoterpenes and thymol in particular degrade rapidly (DT50 16 days in water, 5 days in soil) in the environment and are, thus, low risks because of rapid dissipation and low bound residues, supporting the use of thymol as a pesticide agent that offers a safe alternative to other more persistent chemical pesticides that can be dispersed in runoff and produce subsequent contamination.
Oregano is a flowering plant in the mint family (Lamiaceae). It is native to temperate Western and Southwestern Eurasia and the Mediterranean region.
Thyme is any member of the genus Thymus of aromatic perennial evergreen herbs in the mint family Lamiaceae. Thymes are relatives of the oregano genus Origanum. They have culinary, medicinal, and ornamental uses, and the species most commonly cultivated and used for culinary purposes is Thymus vulgaris.
Plectranthus amboinicus, once identified as Coleus amboinicus, is a semi-succulent perennial plant in the family Lamiaceae with a pungent oregano-like flavor and odor. The origin of Plectranthus amboinicus is unknown, but it may be native to Africa, and possibly India. Plectranthus amboinicus is widely cultivated and naturalized elsewhere in the tropics where it is used as a traditional medicine, spice, and ornamental plant. Common names in English include Indian borage, country borage, Cuban oregano, French thyme, Indian mint, Mexican mint, soup mint, Spanish thyme. Plectranthus is the genus. The species name, amboinicus refers to Ambon Island, in Indonesia, where it was apparently encountered and described by João de Loureiro.
An antimicrobial is an agent that kills microorganisms or stops their growth. Antimicrobial medicines can be grouped according to the microorganisms they act primarily against. For example, antibiotics are used against bacteria, and antifungals are used against fungi. They can also be classified according to their function. Agents that kill microbes are microbicidal, while those that merely inhibit their growth are called biostatic. The use of antimicrobial medicines to treat infection is known as antimicrobial chemotherapy, while the use of antimicrobial medicines to prevent infection is known as antimicrobial prophylaxis.
Phytochemistry is the study of phytochemicals, which are chemicals derived from plants. Those studying phytochemistry strive to describe the structures of the large number of secondary metabolic compounds found in plants, the functions of these compounds in human and plant biology, and the biosynthesis of these compounds. Plants synthesize phytochemicals for many reasons, including to protect themselves against insect attacks and plant diseases. Phytochemicals in food plants are often active in human biology, and in many cases have health benefits. The compounds found in plants are of many kinds, but most are in four major biochemical classes, the alkaloids, glycosides, polyphenols, and terpenes.
Monarda is a genus of flowering plants in the mint family, Lamiaceae. The genus is endemic to North America. Common names include bee balm, horsemint, oswego tea, and bergamot, the latter inspired by the fragrance of the leaves, which is reminiscent of bergamot orange. The genus was named for the Spanish botanist Nicolás Monardes, who wrote a book in 1574 describing plants of the New World.
Origanum dictamnus, known in Greek as δίκταμο or in Cretan dialect έρωντας, is a tender perennial plant that grows 20–30 cm high. It is a healing, therapeutic and aromatic plant that grows wild only on the mountainsides and gorges of the Greek island of Crete, Greece. The dittany of Crete is widely used for food flavouring and medicinal purposes, in addition to it featuring as an ornamental plant in gardens. This small, lanate shrub is easily recognised by the distinctive soft, woolly covering of white-grey hair on its stems and round green leaves, giving it a velvety texture. Tiny rose-pink flowers surrounded by brighter purple-pink bracts add an exuberant splash of colour to the plant in summer and autumn. The dittany is classified as vulnerable on the IUCN Red List of Threatened Plant Species 1997.
A chemotype is a chemically distinct entity in a plant or microorganism, with differences in the composition of the secondary metabolites. Minor genetic and epigenetic changes with little or no effect on morphology or anatomy may produce large changes in the chemical phenotype. Chemotypes are often defined by the most abundant chemical produced by that individual and the concept has been useful in work done by chemical ecologists and natural product chemists. With respect to plant biology, the term "chemotype" was first coined by Dr. Rolf Santesson and his son Johan in 1968, defined as, "...chemically characterized parts of a population of morphologically indistinguishable individuals."
Carvacrol, or cymophenol, C6H3(CH3)(OH)C3H7, is a monoterpenoid phenol. It has a characteristic pungent, warm odor of oregano.
Eucalyptol is a natural organic compound that is a colorless liquid. It is a cyclic ether and a monoterpenoid.
Caryophyllene, more formally (−)-β-caryophyllene, is a natural bicyclic sesquiterpene that is a constituent of many essential oils, especially clove oil, the oil from the stems and flowers of Syzygium aromaticum (cloves), the essential oil of Cannabis sativa, rosemary, and hops. It is usually found as a mixture with isocaryophyllene and α-humulene, a ring-opened isomer. Caryophyllene is notable for having a cyclobutane ring, as well as a trans-double bond in a 9-membered ring, both rarities in nature.
Thymus herba-barona is a species of thyme native to Corsica, Sardinia, and Majorca. It is also sometimes known by the common name caraway thyme, as it has a strong scent similar to caraway, for which it can be used as a substitute in any recipe. It can be used in cuisine or as an evergreen ground cover plant for the garden.
Thymus vulgaris is a species of flowering plant in the mint family Lamiaceae, native to southern Europe from the western Mediterranean to southern Italy. Growing to 15–30 cm (6–12 in) tall by 40 cm (16 in) wide, it is a bushy, woody-based evergreen subshrub with small, highly aromatic, grey-green leaves and clusters of purple or pink flowers in early summer.
Eucalyptus oil is the generic name for distilled oil from the leaf of Eucalyptus, a genus of the plant family Myrtaceae native to Australia and cultivated worldwide. Eucalyptus oil has a history of wide application, as a pharmaceutical, antiseptic, repellent, flavouring, fragrance and industrial uses. The leaves of selected Eucalyptus species are steam distilled to extract eucalyptus oil.
Monarda fistulosa, the wild bergamot or bee balm, is a wildflower in the mint family (Lamiaceae) widespread and abundant as a native plant in much of North America. This plant, with showy summer-blooming pink to lavender flowers, is often used as a honey plant, medicinal plant, and garden ornamental. The species is quite variable, and several subspecies or varieties have been recognized within it.
Thymus pannonicus, known by its common name Hungarian thyme or Eurasian thyme, is a perennial herbaceous plant, distributed in central and eastern Europe and Russia. It grows over open dry meadows, grasslands, and rocks.
Origanum onites, the Cretan oregano, Greek oregano, pot marjoram or Ellinikí rίgani in Greek, is a plant species in the genus Origanum found in Sicily, Greece and Turkey. It has similar flavors as oregano. Its essential oil can be distinguished from other species such as Greek oregano. It has antimicrobial activities.
2,5-Dimethoxy-p-cymene, or thymohydroquinone dimethyl ether, is a phytochemical found in the essential oils of plants within the family Asteraceae. These essential oils, which contain the compound as a major component of the oil, have antifungal, antibacterial, and insecticidal properties.
Thymus zygis is a type of flowering plant in the family Lamiaceae.