Plants caryophyllene from

Marchantia brachiata (Sw.) Schiffn. is a liverwort that also enjoys a wide distribution. It is included here to offset the idea that liverworts of wide occurrence need to exhibit different chemistries in order to attract attention. Nagashima et al. (1999) identified four compounds from plants collected in Ecuador 3,4-dimethoxystyrylbenzene [456], 2,4,5-trimethoxystyrylbenzene [457], P-caryophyllene [458], and bicycloger-macrene [459], In the words of those workers, there was ... ostensibly no metabolic differences between Marchantia brachiata collected in the Netherlands Antilles, Saba, and in Ecuador. ... 

In plant plastids, GGPP is formed from products of glycolysis and is eight enzymatic steps away from central glucose metabolism. The MEP pathway (reviewed in recent literature - ) operates in plastids in plants and is a preferred source (non-mevalonate) of phosphate-activated prenyl units (IPPs) for plastid iso-prenoid accumulation, such as the phytol tail of chlorophyll, the backbones of carotenoids, and the cores of monoterpenes such as menthol, hnalool, and iridoids, diterpenes such as taxadiene, and the side chains of bioactive prenylated terpenophe-nolics such as humulone, lupulone, and xanthohumol. The mevalonic pathway to IPP that operates in the cytoplasm is the source of the carbon chains in isoprenes such as the polyisoprene, rubber, and the sesquiterpenes such as caryophyllene. 

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). 

Kaul et al. (2003) analysed essential oil profiles of various parts of cinnamon. The oil yields of different plant parts were 0.40% in tender twigs 0.36% in the pedicels of buds and flowers 0.04% in buds and flowers 0.33% in the pedicels of fruits and 0.32% in fruits. The tender twig oil was richer in a-phellandrene (3.4%), limonene (1.6%) and (E)-cinnamaldehyde (4%). The volatile oils from pedicels were richer in (EJ-cinnamyl acetate (58.1-64.5%), -caryophyllene (9.6-11.1%) and neryl acetate (1.4—2.0%). Higher amounts of (Z)-cinnamyl acetate (6.1%), a-humulene (2.2%),... 

Both humulene, mentioned in the chapter, and caryophyllene are made in nature from farnesyl pyrophosphate in different plants. Suggest detailed pathways. How do the enzymes control which product is formed ... 

Thus far, more than 1700 compounds from around 1000 plant species have been identified as floral volatiles.84 Twelve compounds in particular, namely, limonene, ( )-/ -ocimene, /3-myrcene, a-pinene, /3-pinene, linalool, 6-methyl-5-hepten-2-one, /3-caryophyllene, benzyl alcohol, 2-phenylethanol, benzaldehyde, and methyl salicylate, have been found to occur in more than 50% of the plant families investigated, and these are regarded as the most common floral volatiles. Various insects use these ubiquitous volatiles for flower selection, for example, honeybee, butterfly, and moth commonly show preferential responses to linalool, benzaldehyde, and/or phenylacetaldehyde contained in the floral scents of various plants.85-87 These volatiles not only serve as important floral cues by themselves but also contribute to the floral scents unique to each plant species, which are distinguishable for flower visitors. On the other hand, it has recently been revealed that several plant species are pollinated exclusively by particular insect species, and that the floral scents play important roles in such pollination. 

The GC-MS and HPLC analyses of oils from Salvia sclarea provided a comparative analysis profile of different plant materials. Sesquiterpene hydrocarbons (e.g., germacrene D and (3-caryophyllene), monoterpene alcohols (e.g., ot-terpineol), diterpenoids (mainly sclareol), monoterpene hydrocarbons (e.g., myrcene, limonene, and the two ocimene isomers), and the principal components (linalyl acetate and linalool) were analyzed. 

The chemical constituents that have been identified in this plant are mainly essential oils and alkaloids. The seeds on steam distillation yielded an oil composed of 75 % monoterpene hydrocarbons, a few sesquiterpene hydrocarbons (3 %) and oxygenated compounds (70). The major constituents included a-phellandrene (50.4 %), a-pinene (5.5 %) and myrcene (4.35 %), germacrene-D-4-ol (9.5 %). Other compounds which were found were a-pinene, -2-carene, jO-caryophyllene, valencene, y-muurolol and carvacryl acetate. Ekundayo and Hammerschmidt (77) identified fifty three constituents of the essential oil from the seeds and found the principal constituent as p-cymene and linalool. Boyom et al. (72) have suggested that the leaves also produce essential oil made up of mostly sesquiterpenes with jO-caryophyllene as the major constituent. However, the apparently odorless leaves, stems and roots of the plant did not yield essential oils on steam distillation in our laboratory (unpublished data). Cimanga et al. (73) have shown that the essential oil from the seed is antibacterial. 

Monoterpenes, on the other hand, possess particularly desirable flavor notes. Three of them, (3-myreene (A.45), limonene (A.46) and p-cymene (A.59) are common to coffee, cocoa and tea, and to numerous plant families (3-myrcene for example constitutes 63% of hop oils. It is worth remembering that they particularly contribute to the flavor of spices. In a study of the effluvia of fresh red coffee berries, Mathieu et al. (1996) identified, in two varieties of robusta, a series of mono- and sesquiterpenes, a blend also present in cold pressed oil from pommelos. In fact, the effluvia of red berries attracts the females of the coffee berry borer, a very important pest. Without giving a list of the hydrocarbons identified in this study, let us note that limonene is the most abundant of them, caryophyllene (4,11,11-trimethyl-8-methylenebicyclo[7.2.0]undec-4-ene), followed by humulene (2,6,6,9-tetramethylundeca-1,4,8-triene) and a-pinene (2,6,6-trimethylbicyclo[3.1.1]hept-2-ene), are rather important in two robusta... 

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