Various essential oils

The former is the more probable constitution. Citral as found in commerce, is probably almost invariably a mixture of the two isomers, which are very similar in their general characters. It occurs to a considerable extent in various essential oils, being the principal constituent of lemon-grass oil, and of the oil of Backhmisia citriodora, and occurring to the extent of about 4 to (i irer cent, in lemon oil, which owes its characteristic flavour to this aldehyde. 

Methyl-heptenone, CgH, 0, occurs in various essential oils, especially lemon-grass oil, in which it is associated with, and difi cult to separate from, the aldehyde citral. 

The hitherto unanswered question whether the chemically identical thujonas isolated from various essential oils are also physically identical, or whether they are physically isomeric, has now been decided by Wallach in the last-named sense. He has succeeded in establishing the presence of two and possibly of three thujones, although with regard to the third the more probable view is, that it represents a mixture of the other two. His examination has, moreover, proved that thuja oil contains essentially... 

Indol, CgH N, is the mother substance of the indigo group of compounds. It exists in various essential oils including neroli oil and oil of jasmin flowers. It is a crystalline compound, melting at 52° and boiling at 253° to 254°. Its odour is powerful and disagreeable, being distinctly faecal in character. Its constitution is as follows —... 

Oh, H.K., Sakai, T., Jones, M. B., and Longhurst, W. M. (1967). Effect of various essential oils isolated from Douglas fir needles upon sheep and deer rumen microbial activity. 

S,2S,AS) —)-trans-V vpcntonc oxide (dihydro rotundifolone) has been isolated for the first time from Mentha longifolia by Reitsema and Varnis. The presence of the (15,25,4i )(—l-ar-isomer was reported in aAf. spicata mutant. Only enantiomerically pure levorotatory piperitone oxides, (15,25, AS)-trans piperitone oxide and (15,25, AR)-cis piperitone oxide, were detected by chiral GC analysis of Micromeria fruticosa and Mentha longifolia The occurrence of the cis- and trans- piperitone oxides was dependent on the population of the species. In most cases, the enantiomeric composition of trans- and cis- piperitone oxides detected in various essential oils is unknown. 

Terpenes are polymers of the 5-carbon compound isoprene (Figure 1.12) and, as such, generally display properties similar to those of hydrocarbons. Terpenoids are substituted terpenes (i.e. contain additional chemical groups, such as an alcohol, phenols, aldehydes, ketones, etc.). Only a few such substances could be regarded as true drugs. Terpenes, such as limonene, menthol and camphor, form components of various essential oils with pseudo-pharmaceutical uses. A number of these molecules, however, exhibit anti-tumour activity, of which taxol is by far the most important. 

Carane-type monoterpenes possess a cyclopropane ring in a bicyclo[4.1.0] skeleton. d-3-Carene 10 is a common constituent in various essential oils. 

Tricydene 11 or l,7,7-trimethyltricydo[2.2.1.0 ]heptane, is a good example which frequently occurs in various essential oils. 

Coumarin 162 (Structure 4.49) is a naturally occurring lactone in crystal form found in hay and tonka beans. It is one of the most used fragrance materials and is responsible for spicy green notes. Dihydrocoumarine 163 is also present in various essential oils with a characteristic sweet herbal odour. Umbellif-erone 164, scopoletin 165, bergaptene 166 and coumarin are found in Rutaceae, Apiaceae, Lamiaceae and Asteraceae oils. Nepetalactones 167 are confined to the oils of Nepeta species [1,3, 21-23, 63]. 

The encapsulation of various essential oils has intrigued the food, cosmetic, and pharmaceutical industries for some time. Several encapsulation systems based on the complex coacervation of gelatin have been used to encapsulate a range of essential oils. However, variable results have been obtained, especially with citrus oils. 

A 53-year-old patient with relapsing eczema had contact allergy to various essential oils used in aromatherapy (7). Sensitization was due to previous exposure to lavender, jasmine, and rosewood. Laurel, eucalyptus, and pomerance also produced positive tests, without previous exposure. 

Derivation (1) From various essential oils (2) by close fractionation of wood turpentine (3) by-product in making synthetic camphor. 

He describes various essential oils that can be used as sources of specific natural flavor chemicals. Among them are leaf alcohol, benzaldehyde and tolualdehyde. This represents a technology which can be employed at the present time, since only classical isolation and separation techniques are required. 

Xylenols which are clear crystalline compounds soluble in alcohol, acetone, and many organic solvents, are present in various essential oils and also in tea, tobacco, roasted coffee, and in various smoked foods. In some cases xylenols contribute to the flavor of these products [1]. 

Olibanum, various essential oils, vanillin-sulfuric acid, daylight Spacial HPTLCfer SOP... 

HPTLC of various essential oils in medicinal incense (Olibanum)... 

Figure 1. Time of half-oxidation (THO) of trans-2-hexenal in various essential oils 1 - control, 2 -black pepper, 3 - berries of juniper, 4 - cardamom, 5 - seeds of caraway, 6 - fennel, 7 - lemon grass, 8 - ginger, 9 - mace Change of main component content in studied essential oils during autooxidation.

Percentage Mortality of LB.A.M after Fumigation with Various Essential Oils... 

Some other common monoterpenoid hydrocarbons are shown in Figure 3.4. Citronellene is also known as dihydromyrcene. It does not occur in nature but is prepared by pyrolytic cracking of pinane. Hydration of the trisubstituted bond of citronellene produces dihydro-myrcenol which is used to provide fresh notes in perfumery. Further details of both of these processes are given in Chapter 9. a-Ocimene occurs in various essential oils such as those of basil, catnip and magnolia, while the P-isomer occurs in the leaf oils of lemon, orange and grapefruit and also in narcissus flowers. Allo-ocimene occurs in the leaves of sequoia trees and is the thermodynamically most stable of the three ocimenes since the double bonds are all in conjugation and as heavily substituted as possible. Double bonds can be isomerised under... 

Geranial, also called citral, is an example of an aldehyde which contains two double bonds. It is an important constituent of various essential oils, among which are those derived from lemons, geraniums, roses, and orange-rind. It is a liquid, which possesses an agreeable odor and boils at 110°-112° under a pressure of 12 mm. An interpretation of the methods used in its synthesis and of its reactions leads to the conclusion that its structure is represented by the formula,—... 

Lalko, J., and A.M. Api. 2006. Investigation of the dermal sensitization potential of various essential oils in the local lymph node assay. Food Chem. Toxicol. 44(5) 739-746. 

FIGURE 5 Structure of various essential oils possesses antimicrobial and antiviral activities. Source Refs. [80,81]. 

C, which darkens on standing in ait. It is the aldehyde derivative of furan and occurs in various essential oils and in fusel oil. It is used as a solvent for extracting mineral oils and natural resins and itself forms resins with some aromatic compounds. 

Minor constit. of various essential oils including petitgrain oil. Bps 135°. 

Mueller, K.. Blum, N. M., and Mueller, A. S. (2013). Examination of the anti-in ammatory, antioxidant and xenobiotic-inducing potential of broccoli extract and various essential oils during mild DSS-induced colitis in rats. ISBN Gastroenterol. 2013, 710-856. 

A number of papers have demonstrated the in vitro effects of various essential oils against meth-icillin-resistant Staphylococcus aureus (MRSA), for example, Lippia origanoides (Dos Santos et al, 2004), Backhousia citriodora (Hayes and Markovic, 2002), M. piperita, M. arvensis and Mentha spicata (Imai et al., 2001), and M. alternifolia (Carson et al., 1995). There have been no trials involving the use of essential oils to combat active MRSA infections, although there have been two studies involving the use of tea tree oil as a topical decolonization agent for MRSA carriers. 

Essential oils are volatile constituents of aromatic plants. These liquid oils are generally complex mixtures of terpenoid and/or nonterpenoid compounds. Mono-, sesqui-, and sometimes diterpenoids, phenylpropanoids, fatty acids and their fragments, benzenoids, and so on may occur in various essential oils (Baser and Demirci, 2007). 

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