Bisabolene sesquiterpenes

Fleischer, T.C., Waigh, R.D., and Waterman, P.G., Bisabolene sesquiterpenes and flavonoids from Friesodielsia enghiana. Phytochemistry, 44, 315, 1997. 

Hi) Bisabolanes (compounds reported— 4) A family of four bisabolene sesquiterpenes, isolated from Barbadian P. americana, was reported by Miller et al. in 1995. The gorgonian extracts yielded the new compound (—)-curcuhydroquinone-1-monoacetate (219), and the known compounds (—)-curcuhydroquinone (200), (—)-curcuphenol acetate (220), and (—)-curcuquinone (221). The structures of all compounds were confirmed by the use of HMQC and HMBC NMR experiments. 

Bisabolene is a sesquiterpene used in the flavoring industry to add fruity flavor to foods [166]. In South Asia, cucurmin, which is the main compound of turmeric, is used in tradicional medicine to treat epilepsy. A detailed investigation found that bisabolene sesquiterpenes were additional molecules responsible for anticonvulsant effects [175]. Interestingly, because of its physicochemical properties, bisabolene has been investigated as an alternative biofuel for replacing D2 diesel [176, 177]. 

Fuganti, C. Serta, S. "Baker s Yeast mediated enantio selective synthesis of the bisabolene sesquiterpenes (+)-epijuvabione and (-)-juvabione "J. Chem. Soc., Perkin Trans. 1, 2000, 97-101. 

Many P-substituted enals such as 29 and (S)-30 (Scheme 3.7) gave the corresponding (S)-alcohols 31 and 32 with excellent stereoselection and in good yields (also in these cases the in situ SFPR strategy was adopted). The products were exploited for the preparation of a wide range of natural bisabolane and bisabolene sesquiterpenes [59,60]. 

As far as we are aware, abscisin II is the only known sesquiterpene possessing the carbon skeleton of structure A. All the other mono-cyclic sesquiterpenes are thought to arise by way of ion D (the example given is bisabolene) or E (the example given is elemol) (21). 

Bisabolene-type sesquiterpenes, e.g. a-bisabolene 74 (Structure 4.20), are widely distributed in nature. This sesquiterpene hydrocarbon is a constituent of bergamot, myrrh and a wide variety of essential oils. Its oxygenated derivatives a-bisabolol [6-methyl-2-(4-methyl-3-cyclohexen-l-yl)-5-hepten-2-ol] 75 and -bisabolol [4-methyl-l-(6-methylhept-5-en-2-yl)cyclohex-3-enol] 76 are found abundantly in chamomile. 

Sesquiterpenes such as 8-caryophyllene, bisabolene and chamazulene found in Artemisia absenturium were shown to possess growth-inhibiting activity (92). Other artemisia species (A. psilastachya and A. acanticarpa) produce several sesquiterpenes, some of which may also be growth inhibitors (93, 94). 

Ginger oil displays considerable compositional diversity but is typically characterized by a high content of sesquiterpene hydrocarbons, including zingiberene, ar-curcumene, (3-bisabolene and (S-sesquiphellandrene. 

A pale olive green essential oil with a sharp, warm, woody spicy odour. Principal constituents are monoterpenes limonone (15-17%), sabinene (9-19%), (l-pinene (5-14%), a-pinene (2-11%), P-myrcene (1.5-2.5%), carene (0.2-14.0%), a-phellandrene (0.5-5.0%), sesquiterpenes P-caryphyllene (9-31%), P-bisabolene (0.1-5.1%) and p-farnescene (1-3%). Box 7.15 shows a chemical analysis and Box 7.16 is a material safety data sheet from a sup-... 

Empirical formula Simplest whole-number formula expressing the composition of a chemical compound. For example, the empirical formula for the sesquiterpene bisabolene is C.Hg, while its molecular formula is three times that, giving C15H24. 

Examples of monoterpenes include the linear aldehyde citral, which is found in many essential oils, and the (cis) alcohol geraniol, a major component of oil of geranium. Cyclic monoterpenes include limonene, menthol, pinene, camphor, and carvone, major components of lemon oil, mint oil, turpentine, camphor oil, and caraway oil, respectively. Sesquiterpenes include farnesol, a component of rose oil, and bisabolene, a component of Bisabol myrrh. The diterpenes include phytol, a component of chlorophyll, and vita-... 

The catalyzed ene reaction has been used for isoprenylation of monoterpenes with an isopropenyl side chain to form sesquiterpenes of the bisabolane group. An example is the three-step conversion of (+)-limonene (1) into / -bisabolene (2). ... 

This selective metalation has been used for the synthesis of several bisabolane sesquiterpenes. Thus the sesquiterpene (- )-J -bisabolene (7) can be synthesized in one step from metalated ( —)-limonene by reaction with I-bromo-3-methyl-2-butene. Two... 

To date over 30 plant terpenoid synthases have been cloned as cDNAs, and many of these were found to encode enzymes of secondary metabolism (43). Isolation and analysis of six genomic clones encoding monoterpene ((—)-pinene and (—)-limonene), sesquiterpene ((E)-a-bisabolene and S-selinene) and diterpene (abietadiene) synthases from Abies grandis, and a diterpene (taxadiene) synthase from Taxus brevifolia have been reported (44). Overexpression of a cotton farnesyl diphosphate synthase (EPPS) in transgenic Artemesia annua has resulted in 3- to 4-fold increase in the yield of the sesquiterpenoid anti-malarial drug, artemisinin, in hairy roots (45). 

Composition Main constituent is zingiberene (>30%) followed by P-sesquiphelland-rene. (-H)-ar-curcumene, (E,E)-a-famesene and (-)-P-bisabolene are further important sesquiterpene hydrocarbons. a-Terpineol and citral (up to 9% in Australian ginger) result in the citrus note, whereas nerolidol is responsible for the woody-soapy taste [115]. Further constituents are camphene, limonene, phellandrene, bomeol, 1,8-cine-ole, linalool, a-bisabolene, oxygenated sesquiterpene hydrocarbons, etc. For recent analytical data see [116, 117, 118]. 

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