Limonene lavender

Linalol is a tertiary alcohol of the formula Cj HjgO, which, with its acetic ester (and traces of other esters) forms the basis of the perfume,of bergamot and lavender oils. By dehydration linalol is converted into terpenes of which the principal are limonene and dipentene, and by esterification into its acetic ester. The examination of the essential oil at different periods of the development of the bergamot fruit has led Charabot and Laloue to the following conclusions. As the fruit matures the essential oil undergoes the following modifications —... 

For hundreds of years the essential oil of lavender has been well appreciated for perfumery purposes [72]. Lavender oil is obtained by steam distillation from the fresh-flowering tops of Lavandula angustifolia Miller (Lavandula officinalis Chaix) [73]. It is a colourless or pale yellow, clear liquid, with a fresh, sweet, floral, herbaceous odour on a woody balsamic base [73, 74]. According to the European Pharmacopoeia, characteristic components of lavender oils are limonene, cineol, 3-octanone, camphor, linalool, linalyl acetate, terpinen-4-ol, lavandulyl acetate, lavandulol and a-terpineol. Adulterations commonly include blends of lavender oils with lavandin oil or spike oil, and the addition of synthetic linalool and linalyl acetate. In contrast, genuine lavender oils contain as main constituents (i )-linalyl acetate and (i )-linalool of high enantiomeric purity (Fig. 17.14). 

Limonene [138-86-3] - [ANALYTICALMETHODS - TRENDS] (Vol 2) -aroma chemical [PERFUMES] (Vol 18) -in Bergamot oil [OILS, ESSENTIAL] (Vol 17) -in caraway oil [OILS, ESSENTIAL] (Vol 17) -in asms oil [OILS, ESSENTIAL] (Vol 17) -in citronella oils [OILS, ESSENTIAL] (Vol 17) -in eucalyptus oil [OILS, ESSENTIAL] (Vol 17) -in expectorants [EXPECTORANTS, ANTITUSSIVES AND RELATED AGENTS] (Vol 9) -m jumperberry oil [OILS, ESSENTIAL] (Vol 17) -in lavender [OILS, ESSENTIAL] (Vol 17) -in lavender [OILS, ESSENTIAL] (Vol 17) -in lime oil [OILS, ESSENTIAL] (Vol 17) -in neroli oil [OILS, ESSENTIAL] (Vol 17) -m oilbanum [OILS, ESSENTIAL] (Vol 17) -in orange oil [OILS, ESSENTIAL] (Vol 17) -in sweet basil oil [OILS, ESSENTIAL] (Vol 17)... 

Examples of essential oil compounds showing these different odours include d-limonene, which has a dull citrus odour while /-limonene has a turpentine odour similarly, d-linalool has a floral, woody (lavender-like) odour, while /-linalool has a floral (petitgrain-like) odour. 

SUMMARY In essential oils, most constituents are terpenes and terpenoid molecules. The method of extraction can influence the terpene content. In citrus oils extracted by expression (squeezing or pressing the plant material), the terpenes present are similar to those found in the living plant tissue for example, orange, lemon, mandarin and grapefruit essential oils may be made up of up to 90% of the monoterpene limonene. When extraction is by steam distillation the action of the hot water and steam on thermolabile (heat-sensitive) molecules present in the plant is responsible for the formation of the bulk of the terpene content. Solvent extraction often produces absolutes that are very low in terpenes or do not contain them at all, when compared to a distillation of the same material, for example as found in lavender and rose products. 

The essential oil contains 30-60% esters (mainly linalylacetate), limonene and cineole. The essential oil is a common constituent in rubefacient preparations. Most lavender oil is used in the perfumery industry and aromatherapy. 

Fig. 2 Total ion chromatogram of monoteipenes present in the gaseous emission of (a) Douglas-fir, (b) Rosemary and (c) Lavender. Peaks 1, a-Thujene 2, (-)-a-Pinene 3, (+) a-Pinene 4, Myrcene 5, Tryciclene 6, (+)-Camphene 7, (-)-Sabinene 8, (-)-Camphene 9, (+)-fi-3-Carene 10, a-Terpinene 11, (+)-p-Pinene 12, (-)-p-Pinene 13, m-Cymene 14, o-Cymene 15, (+)-Limonene 16, (+)-p-Phellangrene 17, (+)-p-PheUangrene 18, 7-Terpinene 19, a-Trpinolene 20,1,8-Cineole 21, (-)-4-Carene 22, (+)-4-Carene 23, (-)-Camphor.

Analysis of individual forms is also important to determine the authenticity of foods or essential oils. The presence of certain forms, such as the geometrical (E)-isomers, is often evaluated as an off-flavour. For example, (-F)-(E)-Hmonene (8-5) is a natural component of citrus essential oils and has a citrus smell like oranges. The isomer (-)-(S)-limonene (8-5), which is the main component of essential oils of silver fir Abies alba, Pinaceae), other conifers and various types of mints Mentha spp.), has a smell reminiscent of turpentine. The alcohol (-)-(E)-Hnalool, also known as licareol (8-18) has a strong woody smeU like lavender, but (-F)-(S)-isomer, also known as coriandrol (8-18) has a sweet smell with lavender tones. Another alcohol (-)-(E)-oct-l-en-3-ol (8-16), has an intense smell of fresh mushrooms, but (-F)-(S)-isomer (8-16) has a smell resembling vegetables with faint mushroom notes. The ketone (-)-(E)-carvone (8-50) has a mint-like smell (and is the main component of spearmint essential oil), while its isomer (-F)-(S)-... 

Lavender oil has been reported to contain more than 100 components, including linalool, linalyl acetate, lavandulyl acetate, terpinen-l-ol-4, 1,8-cineole, camphor, 3-phellandrene, terpinolene, a-thujene, n-hexanal, n-heptanal, methyl amyl ketone, ethyl amyl ketone, perillaldehyde, perillyl alcohol, r/-bomeol, a-terpineol, a-pinene, limonene, lactones (4-butanolide, dihydrocoumarin, 4-methyl-4-vinyl-4-butanolide, 5-pentyl-5-pentanolide, 4,4-dimethyl-2-buten-4-olide, etc.), sesquiterpenes (caryophyllene, cadinene, etc.), fatty acids (propionic acid, isobutyric acid, caproic acid, p-coumaric acid, etc.), and others (list and horhammer). " ... 

A monoterpene found in the volatile oil of bitter orange peel Citrus aurantium L. subsp. amara) and lemon peel [Citrus limon (L.) Burm.]. (7 )-(- -)-isomer is the dominant enantiomer in most plant that produce it, however, both enantiomers (and the racemic form dipentene) are found in different ratios and amounts in many plant products, such as volatile oils of rosemary, lavender, lemon grass, eucalyptus, and others [65], The use of this compound as a fragrance is widespread. The two optical forms of limonene, differ in the intensity of odor, which is stronger in case of (-)-limonene [the odor quality is more turpentine than orange as is for (/ )-(- -)-isomer] [66,67], (7 )-(- -)-Limonene, although not allergenic itself, forms a number of oxidation products which are frequent skin sensitizers. 

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