Clove essential oils nature

A number of other valuable aroma chemicals can be isolated from essential oils, eg, eugenol from clove leaf oil, which can also, on treatment with strong caustic, be isomerked to isoeugenol, which on further chemical treatment can be converted to vanillin (qv). Sometimes the naturally occurring component does not requke prior isolation or concentration, as in the case of cinnamaldehyde in cassia oil which, on dkect treatment of the oil by a retro-aldol reaction, yields natural ben2aldehyde (qv). This product is purified by physical means. 

Clove bud oil is frequendy used iu perfumery for its natural sweet-spicy note but the greatest appHcation is iu the davor area iu a large variety of food products, including spice blends, seasoniugs, piddes, canned meats, baked goods, ready-made mixes, etc. As iu the case of cinnamon bark oil, its well-known antiseptic properties make it ideal for appHcation iu mouth washes, gargles, dentifrices, and pharmaceutical and dental preparations. Candy, particulady chewing gum, is also davored with clove bud oil iu combination with other essential oils. 

This sesquiterpene, or mixture of sesquiterpenes, is found to a considerable extent in nature, especially in clove oil, pimento oil, pepper oil, cinnamon oil, betel oil, copaiba oil, and numerous other essential oils. As isolated from these oils the sesquiterpene has the following characters —... 

In a phenol, a hydroxyl group is attached directly to an aromatic ring. The parent compound, phenol itself, Cr,HsOH (4), is a white, crystalline, molecular solid. It was once obtained from the distillation of coal tar, but now it is mainly synthesized from benzene. Many substituted phenols occur naturally, some being responsible for the fragrances of plants. They are often components of essential oils, the oils that can be distilled from flowers and leaves. Thymol (5), for instance, is the active ingredient of oil of thyme, and eugenol (6) provides most of the scent and flavor of oil of cloves. 

The use of terpenoids, usually as mixtures prepared from plants, dates from antiquity. The several essential oils produced by distillation of plant parts contained the plant essences. These oils have been employed in die preparation of perfumes, flavorings, and medidnals. Examples are oils of clove (local anesthetic in toothache), lemon (flavoring), lavender (perfume), and juniper (diuretic). Usually essential oil production depends on a simple technology which often involves steam distillation of plant material The perfume industry of Soudiem France uses somewhat more sophisticated procedures in the isolation of natural flower oils since these oils are heat sensitive. The separation of oils from citrus fruit residues m California and Florida is done by machine. 

The BP lays down standards for drugs dispensed through a British pharmacy. These standards cover a number of essential oils that appear in the BP, e.g. clove, eucalyptus, peppermint, citronella. However, these are not always appropriate for aromatherapy use because specifications are too broadly based and do not reflect materials currently available and used. For example, the BP states that eucalyptus oil is required to have a 1,8-cineole content of 70%, whereas most natural eucalyptus oils contain less than this. To comply with the BP would encourage a redistillation to rectify the oil, which is entirely contrary to the ethos of aromatherapy. 

Recently a method has been described in the patent literature for the fractionation of essential oils using a fluorinated solvent.Oils studied included clove bud and bergamot, and fractionations could be performed in a semi-continuous mode. Fluorous solvents, as very non-polar media, offer an interesting alternative to the aqueous or alcoholic solvent approaches typically used in natural product extractions. However, it is unlikely that the technique will become widely used in this field. 

Physical processes (see chapter 2) for isolation of natural flavouring substances include distillation, solvent extraction (including supercritical carbon dioxide), and chromatography. Major sources are essential oils. These may be derived from various parts of aromatic plants such as fruits (e.g. citms, fennel), fmit parts (e.g. mace), flowers (e.g. safflower), flower parts (e.g. saffron), flower buds (e.g. clove), bulbs (e.g. onion), barks (e.g. cinnamon), leaves (e.g. basil), leaves and twigs (e.g. mandarin petitgrain), rhizomes (e.g. ginger), roots (e.g. angelica), and seeds (e.g. mustard). 

Various oils present in natural extracts have been classified as fixed oils or high boiling oils and essential or volatile oils. Very popular fixed oils are neem oils (nonedible), coconut, ground nut, soya, Sunflower, mustard etc. oils (edible). Some of the popular essential oils are rose oil, eucalyptus, lemon grass, jasmine, etc. oils of fragrance grade and cumin, coriander, cardamom, clove etc. of flavor grades. 

Clove (Myrtaceae) and Other Essential Oil-Bearing Plants as Sources of Natural... 

CLOVE (MYRTACEAE) AND OTHER ESSENTIAL OIL-BEARING PLANTS AS SOURCES OF NATURAL INSECTICIDES... 

Some essential oils are produced for their chemical constituents, whereas most are produced for their aromatic parts, and it is important that suppliers understand what is expected of them by their customer, whether it is chemical constituents naturally occurring or it is the aroma and avor. Examples of this are turpentine oil, Litsea cubeba oil, sassafras oil, clove leaf oil, and coriander oil. 

Essential oils are volatile compounds responsible for the aromas commonly associated with many plants (see essay "Terpenes and Phenylpropanoids")- The chief constituent of the essential oil from cloves is aromatic and volatile with steam. In this experiment, you will isolate the main component derived from this spice by steam distillation. Steam distillation provides a means of isolating natural products, such as essential oils, without the risk of decomposing them thermally. Identification and characterization of this essential oil will be accomplished by infrared spectroscopy. 

Eugenol is the main component of the essential oil of the clove tree Syzygium aro-maticum) and is one of the cheapest and most common flavor ingredients easily obtained from natural sources. Its low market price makes it an attractive feedstock for vanillin production, but up to now the yields are still unsatisfactory. 

Despite their overall high abundance, the sesquiterpene hydrocarbons ( )-caryophyllene and )S-elemene were not detected by GCO and AEDA. This indicates that these compounds may play either no role or only a minor role in the overall aroma of O. sanctum. Results of AEDA (Table 1) indicate that eugenol cloves) is the predominant odorant in the essential oil, followed by jS-damascenone (floral, applesauce), 2-isopropyl-3-methoxypyr-azine (earthy, potato), and 1,8-cineol (minty, eucalyptus). The fact that eugenol and 1,8-cineol are key aroma components is not surprising and is supported by previous studies [1-9]. However, jS-damascenone and 2-isopropyl-3-methoxypyrazine had not been previously reported as components of O. sanctum. The AEDA procedure was conducted on the fresh herb to determine whether these latter components are indeed natural constituents of the herb or whether they are generated during the production of the... 

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