Terpenes thyme

Terpenes and Camphor.—The importance of these two phenols is in their natural occurrence as ethers in ethereal oils of many plants, e.g., oil of thyme and oil of caraway, and especially in their relationship to the terpenes and camphor, as will be shown later (p. 826, 834). 

Turpentine, which is the sap of coniferous trees, contains in addition to terpenes a non-volatile compound of unknown structure, called abietic anhydride. When the sap is distilled with steam, there are obtained oil of turpentine and abietic acid, C19H28O2, which is non-volatile when the distillation is made without steam the residue is called rosin or colophony. Pinene is the fraction of oil of turpentine which boils at 156° it has the specific gravity 0.86 at 25°. Pinene is present in the oils of rosemary, lemon, sage, juniper, thyme, and anise, and in other essential oils. The structural formulas assigned to pinene is as follows —... 

Conifer wood, balm trees, citrus fruits, coriander, eucalyptus, lavender, lemon grass, lilies, carnation, caraway, peppermint species, roses, rosemary, sage, thyme, violet and many other plants or parts of those (roots, rhizomes, stems, leaves, blossoms, fruits, seed) are well known to smell pleasantly, to taste spicy, or to exhibit specific pharmacological activities. Terpenes predominantly shape these properties. In order to enrich terpenes, the plants are carved, e.g. for the production of incense or myrrh from balm trees usually, however, terpenes are extracted or steam distilled, e.g. for the recovery of the precious oil of the blossoms of specific fragrant roses. These extracts and steam distillates, known as ethereal or essential oils ("essence absolue") are used to create fine perfumes, to refine the flavor and the aroma of food and drinks and to produce medicines of plant origin (phytopharmaca). 

Thyme oil consists entirely of terpenes, the most dominant being a mixture of the phenols thymol and carvacrol. Other compounds present are the alcohols linalool, geraniol and a-terpineol (Stahl-Biskup 1991). Thymol is an expectorant, antimicrobial, anthelminthic and antispasmodic. It is a dermal and mucous membrane irritant and caution is required in its use. The tincture is a safer means of administration than the oil itself. 

Labbe has examined an authentic sample of thyme oil and found it to contain 30 per cent, of thymol, 17 per cent, of a terpene which he could not identify, 15 per cent, of menthene, 21 per cent, of cymene, 5 per cent, of lin ol, 8 per cent, of bomeol, and traces of carvacrol. 

Thymol (26) and carvacrol (27), isolated from herbs such as thyme and savory, are members of the menthane family in which the cyclohexane structure has been oxidized to an aromatic (phenolic) ring. Oils containing these phenolic terpenes have been shown to be particularly effective as antibacterial agents (Kalemba and Kimicka 2003). 

Villanueva et al. reported a comparison between the performance of different green solvents for extracting thymol from different thyme plants. The genus Thymus (Lamiaceae family) is an aromatic plant very rich in essential oil compounds, which are the most valued constituents of the herb. Thyme essential oil is formed by terpenes and its oxygenated derivative compounds (alcohols, aldehydes, ketones, etc.) and is appreciated for food flavoring, in cosmetic, perfumery and in the pharmaceutical industry. 

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