Thymol oregano

Aromatic monoterpenes which contain a benzene ring like p-cymene 9, car-vacrol 12, thymol 13 and phenylethyl alcohol 14 (Structure 4.4) are common constituents of many essential oils, e.g. oregano (Origanum sp.), thyme (Thymus sp.), savory (Satureja sp.) and rose (Rosa sp.) oils. Another important constituent class of essential oils is phenypropanoids [36]. They are not considered as terpenoids owing to their different biogenetic origins, which will be mentioned later. 

Thymol (2-isopropyl-5-methylphenol) Found in essential oils of thyme and oregano. Strong medicated, herbaceous odour. 

Oregano Origanum virens L. is an perennial herb with 40-70 cm high and very aromatic. This plant grows in open and dry countries, at altitudes lower than 500-700 m. The major components of essential oil from Origanum virens L. are terpineol, a-pinene, camphor, thymol, carvacrol and cineole. Compounds such as alcohols and dipentene are also present. 

Main components Up to 3% essential oil with carvacrol, rarely thymol, as main constituent, as well as p-cymene, linalool, bomeol, terpinene-4-ol. On the composition of various oregano oils see [186],... 

Mexican oregano is used in the USA, and derives from various Lippia species, especially Lippia graveolens (Verbenaceae) its taste is reported to be less fresh and pleasant [190[. Main constituents are thymol, carvacrol, p-cymene [191 [. 

Separation of the phenolic flavor components, carvacrol and thymol, from oregano leaves. 

Spanish oregano oil contains up to 50% thymol and 7 to 8% a-pinene, cineole, linalyl acetate, linalool, dipentene, p-cymene, and p-caryophyllene. Other varieties contain carvacrol as the major component. 

Most contain carvacrol and thymol in varying amounts. Dried oregano will contain 0.2 to 0.4% of a yellowish volatile oil with thymol and carvacrol in varying amounts. The phenolic content may be 50 to 65%. Carvacrol is found in the oil of oregano, thyme, marjoram, and summer savory. It is practically insoluble in water. It is used as a disinfectant and in organic synthesis. Therapeutically, it is used as an anti-infective and anthelmintic. 

A problem that occurs now and then is that a producer of herbs partially extracts them, separates the components, sells them separately, and then sells the partially extracted leaves as originals. This is a fraud, unless the label indicates a partial extraction. An activist group suspects that such an operation is going on involving the removal of carvacrol and thymol from oregano leaves and demands an immediate analysis. You are to extract some leaves they suspect and compare the amount recovered to a known quality product. 

Carvacrol, 5-isopropyl-2-methylphenol, 4 mg/mL of mobile phase, 2 mL/S Thymol, 2-isopropyl-5-methylphenol, 4 mg/mL of mobile phase, 2 mL/S Sample Oregano leaves, 10 g/S /-Butyl methyl ether, (HjCjjC-O-CHj, 100 mL/S... 

Refer to Figure E16-1, p. 552. Ten grams of oregano leaves is reflux extracted with /-butyl methyl ether for 20 minutes, and the solvent evaporated at room temperature overnight. The CCC column is filled with stationary phase, and then mobile phase is passed into it. Standards of both thymol and carvacrol are run, and 20 1-minute fractions are collected. The content of each fraction is determined at 276 nm, and their partition ratios are determined. The sample residue is taken up in 5 mL of mobile phase and 0.50 mL is added. The peak area is compared to that shown in Figure El 6-2, p. 552, which was obtained under the same conditions. 

Extracts derived from most members of the Labiatae family (Table 3) have the potential to reduce the oxidation of food products and extend shelf life. This antioxidant action is dependent on the ability of the constituent phenolics to scavenge free radicals and chelate metals [27]. This dual effect has implications for CHD since it has been proposed in some studies, mainly from Europe, that a high status of iron increases the risk of CHD [28]. A number of the active compounds found in rosemary have also been found in sage and other herbs. In oregano, four flavonoids were identified among the active fraction [29], while in thyme, dimers of thymol and flavonoids have been isolated and characterized. 

Occurrence In numerous essential oils cymen-2-ol especially in origanum (oregano) oil (Coridothymus capitatus, Lamiaceae) up to 80%, in savory and thyme oil up to 70% cymen-3-ol especially in essential oil of seeds of Orthodon angustifolium (Lamiaceae) up to 72% cymen-8-ol from the frass of the old house borer beetle Hylotrupes bajulus (Cerambycidae). Use Carvacrol as disinfectant and solvent thymol as stabilizer (0.01%) of halothanes and trichloroethene. Mixtures of thymol with methyl IV-methylanthranilate in appropriate ratios have a typical mandarin odor. lit Tetrahedron Lett. 1975, 3585. Helv. Chim. Acta 46, 1480(1963). 

While present in only a relatively few aromatic herbs, phenolic volatile oils are among the most potent and potentially irritant compounds found in essential oils. Phenols are represented in both major classes of aromatic compounds—the monoterpenes and phenylpropanoids. The major monoterpene phenols, thymol and carvacrol, are found in thyme. Thymus spp., and oregano. Origanum vulgare (Lamiaceae). 

Lambert, R.J.W., P.N. Skandamis, P.J. Coote, and G. J.E. Nychas, 2001. A study of the minimum inhibitory concentration and mode of action of oregano essential oil, thymol and carvacrol. 

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