Caryophyllene cloves

Formula (1) would thus indicate the natural dextro-caryophyllene of clove stems formula (2) indicates the highly laevo-rotatory caryophyllene resulting from regeneration by means of pyridine, and (3) may represent the a-caryophyllene of Deussen. 

Caryophyllene nitrosochloride, (CjgHgJjN OoCL, is obtained when a mixture of the sesquiterpene, alcohol, ethyl acetate, and ethyl nitrite is cooled in a freezing mixture, and then treated with a saturated solution of hydrochloric acid in alcohol. The reaction mass is allowed to stand on ice for an hour and is then exposed to sunlight. Thus prepared it melts at about 158° to 163°, and can be separated into two compounds, one being that of a-caryophyllene and the other that of yS-caryophyllene Deussen s sesquiterpenes of natural caryophyllene from clove oil), a-caryophyllene nitrosochloride melts at 177", and /3-caryophyllene nitrosochloride at 159°. They can be separated by fractional crystallisation. The corresponding a-nitrolbenzylamine melts at 126° to 128°, and the /3-nitrolbenzylamine at 172° to 173°. The bimolecular formula given above is probable but not certain. 

Propose a mechanistic pathway for the biosynthesis of caryophyllene, a substance found in clove oil. 

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 ... 

The main component of all clove oils is eugenol (up to 80%, sometimes more), which is responsible for their odor and antiseptic properties. Other major constituents are eugenyl acetate and caryophyllene [442-449]. Clove bud oil has a higher acetate content and a more delicate odor than the other oils, therefore it is much more expensive. Leaf oil is produced and used in the largest quantities. The composition of clove stem oil resembles that of bud oil but with a lower content of eugenyl acetate. 

Caryophyllene, a common constituent of essential oils, was first isolated from clove oil. )S-Caryophyllene [( )-caryophyllene] 105 (Structure 4.30) is the most widely encountered form of caryophyllenes. Caryophyllene derivatives (106-108) are characteristic constituents of most birch oils [49-51]. 

Eugenol (80-90%), acetyleugenol (2-3%), caryophyllene, furfural, methyl amyl ketone, salicylic acid (small quantity) Clove stem oil, cedarwood, copaiba or gurjun oil, phenol, oil of turpentine. Chief test estimation of eugenol... 

Clove Syzygium aromaticum (Eugenia caryophyllus) (Myrtaceae) dried flower buds 15-20 eugenol (75-90) eugenyl acetate (10-15) P-caryophyllene (3) flavour, aromatherapy, antiseptic... 

The main constituent of clove oil is eugenol (70-90%), acetyl eugenol (2-17%), and p-caryophyllen (5-12 %) [9-12]. Clove oil can be obtained from other parts of the tree, such ass the buds, stem, or leaves. The eugenol content of clove oil depends upon the condition of the cloves and on the method of distillation [12]. 

The minor constituents like methyl amyl ketone, methylsalicylate, etc., are responsible for the characteristic pleasant odour of cloves. The oil is dominated by eugenol (70-85%), eugenyl acetate (15%) and /Tcaryophyllene (5-12%), which together make up 99% of the oil. /3-Caryophyllene, which was earlier thought of as an artefact of distillation, was first reported as a constituent of the bud oil by Walter (1972). 

Pino et al. (2001) identified 36 compounds of the volatile oil of clove buds. The major components of the bud oil were eugenol (69.8%), (3-caryophyllene (13%) and eugenyl acetate (16.1%) (Pino et al., 2001). The chief components of clove oil from various regions are listed in Table 8.5, which indicates quantitative variations of the individual components of the oil from different regions. Zachariah et al. (2005) reported that clove buds from India contained 12.9-18.5% oil, of which 44-55% was eugenol, whereas the pedicels contained 3.0-7.7% oil with 60.0-72.4% eugenol. 

The leaf oil from Madagascar contained 22 constituents, the chief constituents being eugenol (82.0%) and /1-caryophyl-lene (13.0%). It contained a higher level of /t-caryophyllene compared with bud oil (7.2%) (Srivastava et al., 2005 Table 8.7). A commercial sample of leaf oil obtained in Germany contained 76.8% eugenol and 17.4% /3-caryophyllene as the chief components (Jirovetz etal., 2006).The constituents of various clove oils are indicated in Tables 8.6 and 8.7. 

The essential oil content during the different stages of leaf growth revealed that the eugenol content in the leaves increased from 38.3 to 95.2% with maturity, while the contents of eugenyl acetate (51.2 to 1.5%) and caryophyllene (6.3 to 0.2%) decreased (Gopalakrishnan and Narayanan, 1988). Clove bud and leaf oil contain various classes of compounds, e.g. monoterpenes, sesquiterpenes, aldehydes and ketones (Vernin et al., 1994), which are indicated in Table 8.8. 

Eugenol, the primary component of clove s volatile oils, functions as an antiinflammatory substance. In animal studies, the addition of clove extract to diets already high in anti-inflammatory components (like cod liver oil, with its high co-3 fatty acid content) brings a synergistic effect. In some studies, it further reduces inflammatory symptoms by another 15-30%. Clove also contains a variety of flavonoids, including kaempferol and rhamnetin, which also contribute to clove s anti-inflammatory and antioxidant properties. Another constituent of clove oil, /J-caryophyllene, also contributes to the anti-inflammatory activity (Ghelardini et al., 2001). 

Caryophyllene Cyclic and has a strong woody, spicy odour, found in oil cloves, lavender, sweet thyme and ylang ylang. 

Clove Eugenia caryophyllata Eugenol, (-)-caryophyllene (87), eugenyl acetate (88) 95,101... 

The oil is obtained in a yield of 3 to 5 per cent it has a yellowish to yellowish-brown colour, and an odour somewhat resembling that of cloves, owing to the presence of eugenol and caryophyllene, which they both contain. 

The leaf oil is used mainly for the production of eugenol and caryophyllene, because of its harsher note, which does not represent the typical clove flavour. 

Caryophyllene is the main hydrocarbon component of clove oil, from which it is produced as a by-product of eugenol extraction. The endocyclic double bond of caryophyllene is highly strained and reacts readily with a variety of reagents. Usually both double bonds become involved in a trans-annular reaction, followed by rearrangements to give mixtures of polycyclic products. Some of these mixtures find use as woody ingredients in perfumes. Caryophyllene and two typical reaction products from it are shown in Scheme 4.29. 

Figure 6. Change of main component content (%) in the composition of clove essential oil during 5 months of storage in light 1 - eugenol, 2 - P-caryophyllene, 3 - famezene, 4 - eugenyl acetate, 5 - 8-cadinene, 6 - caryophyllene oxide.

According to the Merck Index - Clove oil, 82-85% eugenol, including about 10% acetyl eugenol, caryophyllene, small quantities of furfural, vanillin, and methyl ethyl ketone. 

C Essential oil of Caryophylli flos (clove oil, 5) shows as major compound the orange-brown zone of eugenol (T3, R, 0.5) and the violet zone of (i-caryophyllene at the solvent front. 

Some common terpenes include geraniol, found in geraniums limonene, oil of orange a-pinene, or oil of turpentine a-farnesene, oil of cintronella zingiberene, oil of ginger farnesol, found in lily of the valley P-selinene, oil of celery and caryophyllene, oil of cloves. Isoprene is also produced in animal bodies and is said to be the most common hydrocarbon present in the human body. By one estimate, a 70-kilogram (150-pound) person produces about 17 milligrams of... 

The major terpenoid components of cloves and hops are remarkable in that they contain highly strained medium sized rings. Four of the most important members of the family are shown in Figure 7.29. Of these, the most important are P-caryophyllene (7.137) and a-humulene (7.139). These are the most frequently encountered in essential oils and are often referred to simply as caryophyllene and humulene, respectively. For convenience, these shorter names will be used in this book. For example, a-humulene (7.139) has been found in hundreds of essential oils whereas there are reports of P-humulene (7.140) in only a few. Almost invariably, several members of the family will be found together in oils. For example, all oils which have been found to contain humulene (7.139) also contain caryophyllene (7.137) and isocaryophyllene (7.138). 

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