Oil of cloves

Cloves consist of the unopened flower-buds picked when the fleshy receptacle, which is at first green, has acquired a crimson colour. At this period of its growth the clove is richest in oil 

Ninety per cent of the world s supply of cloves is obtained from the two islands Zanzibar and Pemba, where it was introduced from Reunion, via the Moluccas, about 1818, and where it forms the chief industry. As one approaches the islands when the cloves are in hloom, one is struck by their pervading sweet odour, which is infinitely more pleasant than that of the dried flowers or the oil. The industry has undergone many vicissitudes in 1872 a hurricane practically destroyed most of the plantations in Zanzibar, but Pemba escaped, and the industry has since become very prosperous. 

It h as been suggested that a clove oil factory might be established in Zanzibar, where the necessary timber for fuel is abundant, but there are many practical difficulties For. Office Ann. Series, No. 2653, via J. Soc. Chem. Ind. 1901, 20. 776) and all attempts made hitherto have been unsuccessful. 

The area of clove cultivation in Zanzibar and Pemba for the year 1919 was estimated at 52,000 acres, with nearly 5,000,000 trees. The large plantations are held by Arabs, a few by Indians. The yield from each tree varies, especially good crops recurring every three to five years. The average yield per annum from a plantation of 3,000 sixty-year-old trees, owned and managed by Europeans, is 8 lb. per tree, which could be increased by judicious pruning. 

An idea of the extent of the clove crop may be gained from the figures for the 1924 harvest, which amounted to between 7,000 and 8,000 tons. For the six months from January to June 1914, 2,764 tons were exported of this, India took 58 per cent, the United Kingdom 16 per cent, and the United States 10 per cent. 

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How then would you make eugenol (TM 320), a constituent of oil of cloves ... 

Methyl Amyl Ketone. Methyl amyl ketone [110-43-0] (MAK) (2-heptanone) is a colorless Hquid with a faint fmity (banana) odor. It is found in oil of cloves and cinnamon-bark oil, and is manufactured by the condensation of acetone and butyraldehyde (158). Other preparations are known (159-162). 

Semmler and Mayer have isolated a sesquiterpene alcohol, from the high boiling fractions of oil of cloves.. It was probably not obtained in an absolutely pure condition, but had the following characters, which must be regarded as approximate only —... 

This ketone has been isolated from oil of rose, and in traces, from oil of cloves. It has the following constitution —... 

A very small amount of aceteugenol is present in essential oil of cloves. Its constitution is as follows —... 

Nelke,/. clove pink (the flower). Nelken-gewachse, n.pl. (Boi.) Caryophylla-ceae. -kassie, /. clove cassia, -ol, n. clove oil, oil of cloves, -pfeffer, m. allspice, pimento, -pfefferwasser, n. (Pharm.) pimento water, -rinde, /. clove cassia, -s ure, /. eugenol caryophyllic acid, -stein, m. iolite. -wurzel, /. avens root. -zim(m)t, m. clove cinnamon, clove cassia. 

Furfuryl alcohol Oil of cloves Coronaric acid Chrysanthamum coronarium... 

Sf.lf-Tfst 8.14A When 250. mg of eugenol, the compound responsible for the odor of oil of cloves, was added to 100. g of camphor, it lowered the freezing point of camphor by 0.62°C. Calculate the molar mass of eugenol. 

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 ZOE cement has a long history. Eugenol is the essential constituent of oil of cloves, which has been used medically since the fourth century... 

Molnar, 1942). Its use specifically to relieve toothache was recorded by Vigo in the sixteenth century and reactions with metal oxides were reported by Bonastre (1827a,b). The earliest zinc oxide chelate cements used creosote (King, 1872) and later this was mixed with oil of cloves (Chisholm, 1873). Then oil of cloves was used by itself (Flagg, 1875) and finally its essential constituent, eugenol (Wessler, 1894). 

The ZOE impression paste is essentially a two-paste ZOE cement. One paste is formed by plasticizing the zinc oxide powder with 13 % of mineral or vegetable oil. The other paste consists of 12% eugenol or oil of cloves, 50% polymerized rosin, 20% silica filler, 10% resinous balsam (to improve flow) and 5 % calcium chloride (accelerator). 

Molnar, E. J. (1942). Cloves, oil of cloves and eugenol. Their medico-dental history. Dental Items of Interest, 64, 521-8. 

To add to the cost further, many of these compounds are rather sensitive to temperature and would decompose before vaporizing. For example, oil of cloves (from Eugenia caryophyllata) is rich in the phenol eugenol (V), which has a boiling point of 250 °C). We cannot extract the oils via a conventional distillation apparatus. 

There are several related phenolic compounds found in the volatile oil of clove. The primary one is eugenol, accounting for 85% of the total (figure 8.14) (Tyler 1994 Robbers et al. 1996). 

The sesquiterpenoids caryophyllene and its geometrical isomer occur naturally in the oil of cloves. Plan a synthesis of a suitable starting material containing a four membered ring ... 

Oil of clove is mainly useful in relieving pain in toothache. 

Srivastava, . C. and N. Malhotra. 1991. Acetyl eugenol, a component of oil of cloves (Syzygium aromaticum L.) inhibits aggregation and alters arachidonic acid metabolism in human blood platelets. Prostaglandins Leukot. Essent. Fatty Acid 42 73-81. 

Cinnamon.—The bark of the lawns cinnamomum, and that from Ceylon is the best. It is very thin, brownish-red, and has an agreeable aromatic flavor.. The oassia, winch it resembles closely, is thicker, rougher on the surface, and comes in larger rolls or quills. The first is often sophisticated with the latter, and sometimes even a part of its volatile oil is abstracted by infusion in alcohol. This latter fraud is detected by the feeble smell and teste of the cinnamon. The finely-groimd hark is used for pastilles, sachets, an tooth-powders. Its aroma may also be extracted in the form of tincture, by alcohol. By distillation, it yields an essentia] oil of powerful odor, which is largely used in combination with oil of cloves and other strong essences. (... 

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. 

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