Camphene eucalyptus

Major components listed under a general heading for eucalyptus would be citronellal, cineole, camphene, fenchene, limonene, phellandrene and pinene. The individual species show the different proportions (amounts shown are approximate percentages) ... 

Bornane monoterpenes are exemplified by camphene (2,2-dimethyl-3-methylene-bicyclo[2,2,1]heptane), a structure in which two fused cyclopentane rings share three Cs. We can simply represent the camphene skeleton as a cyclohexane with a methylene (—CH2—) cross-link (G6(-CH2—)). The keto derivative camphor (camphor smell), the ether eucalyptol (eucalyptus smell) and the simple bornene a-pinene (pine smell) are familiar examples. 

Terpenes are components of various products e.g. tobacco smoke, wax pastes (furniture and floor polishes etc.), liquid waxes (floor polishes etc.), cleansers (detergents etc.), polishes, dyes and varnishes, synthetic resins, so-called natural building products, deodorants, perfumes, softeners, air fresheners, foods, beverages, pharmaceutical products (e.g. camomile oil, eucalyptus oil). In these products terpene compounds such as geraniol, myrcene (beta-myrcene), ocimene, menthol, alpha-pinene, beta-pinene, d-limonene, 3-carene, cineole, camphene or caryophyllene can be detected. 

Myrcene (70) is very widespread in nature. Some sources, such as hops, contain high levels and it is found in most of the common herbs and spices. All isomers of a-ocimene (84), b-ocimene (85), and alio ocimene (86) are found in essential oils, the isomers of b-ocimene (85) being the most frequently encountered. Limonene (73) is present in many essential oils, but the major occurrence is in the citrus oils that contain levels up to 90%. These oils contain the dextrorotatory (/ ) -enantiomer, and its antipode is much less common. Both a phellandrene (87) and b phellandrene (88) occur widely in essential oils. For example, ( ) a phellandrene is found in Eucalyptus dives and (5)-(-)-b-phellandrene in the lodge-pole pine, Pinus contorta. p Cymene (83) has been identi ed in many essential oils and plant extracts and thyme and oregano oils are particularly rich in it. a-Pinene (65), b-pinene (7, and 3-carene (77) are all major constituents of turpentine from a wide range of pines, spruces, and rs. The pinenes are often found in other oils, 3 carene less so. Like the pinenes, camphene (89) is widespread in nature. 

Eucalyptus oil contains usually 70-85% of eucalyptol (1,8-cineole) other constituents present are mostly monoterpene hydrocarbons (a-pinene, S-limonene, -cym-ene, P-pinene, a-phellandrene, camphene, y-terpinene, etc., with the first three in major amounts), with lesser amounts of sesquiterpenes (e.g., aromadendrene, allo-aromaden-drene, globulol, epiglobulol, ledol, and viridi-fiorol), aldehydes (e.g., myrtenal), ketones (e.g., carvone and pinocarvone), and others (jiANGSu). The eucalyptol content is 61.2% and 83.9% in Brazilian and Chinese eucalyptus, respectively. 

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