Essential oils constituents

About 120 chemical constituents have been identified in chamomile as secondary metabolites, including 28 terpenoids, 36 flavonoids and 52 additional compounds [4]. A substantial part of drag effects are determined by the essential oil content. Oil is collected from flower heads, either by steam distillation or solvent extraction, for yields of 0.24-1.90% of fresh or dry plant tissue. Among the essential oil constituents the most active are /-/-a-bisabolol and chamazulene. /-/-a-bisabolol has demonstrated anti-inflammatory, antispasmodic, antimicrobial, antiulcer, sedative and CNS activity. Chamazulene is also anti-inflammatory. Topical applications of chamomile preparation have shown benefit in the treatment of eczema, dermatitis and ulceration [5]. 

Essential oil constituents can be classified as terpenoids and non-terpenoid hydrocarbons. 

Hypericum perforatum (Clusiaceae), commonly known as SJW, is used in many countries for the treatment of mild-to-moderate forms of depression. Several clinical studies provide evidence that SJW is as effective as conventional synthetic antidepressants (46-51). From a phytochemical point of view, H. perforatum belongs to one of the best-investigated medicinal plants. A series of bioactive compounds have been detected in the crude material, namely phenylpropanes, flavonol derivatives, biflavones, proanthocyani-dins, xanthones, phloroglucinols, some amino acids, naphthodianthrones, and essential oil constituents (Fig. 3) (52-54). 

Further, ginseng constituents are polysaccharides, essential oil constituents, polyacetylenes, peptides, and other lipids (7). Ginseng is included in the pharmacopeias of several countries such as China, Germany, and the United Kingdom (113). Modern therapeutic claims refer to vitality, immune function, cancer, cardiovascular diseases, and sexual function (114,115). More than 500 studies have been published on the pharmacological activity of ginseng (7,80). 

Montes (176) analysed the essential oil constituents using the principle of chromatographic adsorption with the aid of columns of silicic acid and bentonite. The compounds were then crystalized and their melting points were deter-det ermined. 

The purposes of our research were to evaluate the feasibility of supercritical carbon dioxide extraction of lemon oil near ambient temperature, generate equilibrium data for carbon dioxide with multicomponent essential oil constituents, and evaluate the ability of the Peng-Robinson equation of state ( ) to model this multicomponent supercritical system. 

Table I. Thermally Degraded Compounds Derived from Essential Oil Constituents...

The curry leaf plant is highly valued for its characteristic aroma and medicinal value (Philip, 1981). A number of leaf essential oil constituents and carbazole alkaloids have been extracted from the plant (Mallavarapu et al., 1999). There are a large number of oxygenated mono- and sesquiterpenes present, e.g. c/s-ocimene (34.1%), a-pinene (19.1%), y-terpinene (6.7%) and P-caryophyllene (9.5%), which appear to be responsible for the intense odour associated with the stalk and flower parts of curry leaves (Onayade and Adebajo, 2000). In fresh bay leaves, 1, 8-cineole is the major component, together with a-terpinyl acetate, sabinene, a-pinene, P-pinene, P-elemene, a-terpineol, linalool and eugenol (Kilic et al., 2004). 

Table 3.9. GC-MS-based comparison of essential oil constituents of Indian, Guatemalan and Sri Lankan cardamom.

Korikanthimath, V.S., Mulge, R. and Zachariah, T.J. (1999) Variations in essential oil constituents in high yielding selections of cardamom, journal of Plantation Crops 27, 230-232. 

Kojima, H., Yanai, T., Toyota, A., Hanani, E. and Saiki, Y. (1 998) Essential oil constituents from Curcuma aromat-ica, C. tonga and C. xanthorrhiza rhizomes. In Ageta, H., Aimi, N., Ebizaka, Y., Fujita, T. and Honda, G. (eds) Towards Natural Medicine Research in the 21st Century. Elsevier, Amsterdam, pp. 531-539. 

Phytochemistry of cinnamon and cassia deals mainly with the volatile components. Besides essential oil constituents, several diterpenes have been isolated from the genus. These include cinncassiols A, B, (% and... 

Ahmed, A., Choudhary, M.I., Farooq, A., Demirci, B., Demirci, F. and Baser, K.H.C. (2000) Essential oil constituents of the spice Cinnamomum tamala (Ham.) Nees and Eberm. Flavour and Fragrance Journal 1 5, 388-390. 

Ur-Rahman, M.I., Choudhary, A., Farooq, A., Ahmed, M.Z., Iqbal, B. and Demirici, F. (1 999) Antifungal activities and essential oil constituents of some spices from Pakistan. Third International Electronic Conference on Synthetic Organic Chemistry (ECSOC-3), September 1-30, 1999, 1 0 pp. 

Bagchi, G. D. Haider, F. Dwivedi, P. D. Singh, A. Naqvi, A. A. Essential oil constituents of Artemisia annua during different growth periods at monsoon... 

The conversion of eugenole into iso-eugenole and of safrole into iso-safrole is accomplished by boiling with alcoholic potassium hydroxide. The oxidation products of these ethers are other important essential oil constituents. Eugenole yields the corresponing aldehyde which is known as vanillin, the chief constituent of vanilla beans from which vanilla extract is made. Safrole by oxidation yields a compound known as piperonal also as heliotropine. It has the odor of heliotrope flowers and is used as artificial heliotrope essence. These latter compounds and also constituents of other essential oils will be considered in detail later in their proper chemical relationship (p. 66i, etc.). 

Anis Aldehyde.—The simplest essential oil constituent of this group is one found in anis seed oil and known as anis aldehyde. 

Vanillin.—Two very important essential oil constituents are ether derivatives. One of these is vanillin, the chief constituent of vaniUa beans from which vanilla extract is made, and the other is heliotropin, also known as piperonal, which has the odor of heliotrope flowers. Vanillin is the mono-methyl ether of protocatechuic aldehyde, the methoxy... 

Relation to Eugenole, etc.—By far the most important syntheses of these important essential oil constituents are by the oxidation of the corresponding ethers of di-hydroxyl derivatives of benzene homologues... 

Table 2 hRf values of some oxygenated terpenes and other essential oil constituents on silica gel in various eluent systems... 

Gokhale, N.N., et. al., "The Mode of Recovery of the Essential Oil Constituents from the Minute Cells of the Plant Materials During Steam Distillation," Proceedings of the 7th International Essential Oil Congress, Kyoto 1977, p. 242-247... 

Eucalyptus citriodora Hook f (Lemon gum) The oil of the fresh leaves of E. citriodora (2.2-8.3%), a tree introduced into Kenya from Australia (68), has been well researched in Kenya. Results indicate that there are two chemical varieties that were introduced. The chief essential oil constituents of one variety are citronellal (65-88%), citronellol (2-25%) and isopulegol (2-19%). In constrast, the second variety has as its major essential oil consitutents citronellol (32-52%), citronellal (38-59%) and 1,8-cineole (2-19%) (68,69). The essential oil is regarded as a perfumery oil. This plant is the second most commercially important Eucalyptus species in the essential oil trade and is only second to E. smithii Baker (69). The aromatic oil is used in soaps, creams and lotions due to its desirable odor properties, and as with many other essential oils is also used extensively in many technical preparations to mask other industrial malodors. A highly active mosquito repellent compound, p-menthane 3,8-diol has been isolated from the waste water of distillation of E. citriodora. There are now many commercial mosquito repellents based on this waste water (70-73). 

Lippia carviodora Meikle Carvone (about 60%) was the major compound in the essential oil of partially dried leaves of L. carviodora Meikle with the yield of 3%. Other essential oil constituents included limonene (2.4-32.7%), carvinyl acetate (0-19.3%), andp-cymene (1.1-5.7%) (79,80). 

Some essential oil constituents are partly water soluble and are not always separated in the oil separation. When this occurs, the separated water must be brought to the boil again (cohabitation). Rose oil and orange flower oil are treated this way to recover the dissolved oil. 

This sequence was used in a remarkably simple synthesis of the essential oil constituent a-santalol (6) from the aldehyde (5). This substance had been synthesized previously by the reaction of (5) with (carboethoxyethylidene)triphenyl-... 

GC-mass spectrometry (GC-MS) is most frequently and effectively used to identify the essential oil constituents by using database libraries of both retention indices and mass spectral fragmentation patterns. LC-mass spectrometry is less frequently used for the identification of the essential oil constituents due to increased experimental complexity. One of the recent technological developments is the combined use of GC-MS and FTIR spectrometries which can provide additional real time information for molecular identification without the need for macroscopic separation of mixtures [55,61-67]. 

Only the pentadecatrienyl derivatives (84 - 87), which are the most abundant in each group of the essential oil constituents, inhibited invertase moderately (more than 30%) at a concentration of approximately 600 (iM (Table 7). 

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