Terpene compounds

Essential Oils. Volatile oils from plants are referred to as essential oils. The oils can be obtained through steam distillation, solvent extraction, or separation of the oils from pressed fmit. They consist of oxygenated compounds, terpenes, and sesquiterpenes. The primary flavor components of essential oils are oxygenated compounds. Terpenes contain some flavors but are often removed from the essential oil because they are easily oxidized (causiag off-flavors or odors) and are iasoluble. Essential oils are prepared from fmits, herbs, roots, and spices. 

One thing that became apparent in our investigation of this perfume mixture was that the terpenoid family of compounds (terpenes and substituted terpenes) all undergo CAD to form a prominent 81+ ion (CsHg ). A Parent Ion Scan for this... 

Most terpenes are known by their historic trivial names, although systematic names may be used for simple compounds. Terpenes are also classified according to the number of carbon atoms in their structures (Table 1.5). 

The special potential for constructing double bonds stereoselectively, often necessary in natural material syntheses, makes the Wittig reaction a valuable alternative compared to partial hydrogenation of acetylenes. It is used in the synthesis of carotenoids, fragrance and aroma compounds, terpenes, steroides, hormones, prostaglandins, pheromones, fatty acid derivatives, plant substances, and a variety of other olefinic naturally occurring compounds. Because of the considerable volume of this topic we would like to consider only selected paths of the synthesis of natural compounds in the following sections and to restrict it to reactions of phosphoranes (ylides) only. 

Davies P 1999 Aromatherapy an A to Z, 3rd edn. CW Daniel, London Devon T K, Scott A1 1972 Handbook of naturally occurring compounds terpenes, volume 2. Academic Press Inc, New York Doty R L 2003 Handbook of olfaction and gustation. Marcel Dekker, New York Ernst E 2006 The desktop guide to complementary and alternative medicine an evidence based approach. Mosby, London... 

Flavor Components. Olive oil volatiles contain at least 100 compounds (33-37) in several categories hydrocarbons (5 compounds), aliphatic alcohols (13 compounds), terpenic alcohols (4 compounds), aldehydes (27 compounds), ketones (8 compounds), ethers (2 compounds), furans (3 compounds), thiophenes (6 compounds), and esters (29 compounds). 

Besides the Maillard reaction, fat oxidation and thiamine degradation, more aroma compounds in process flavours are formed by the interaction of these different reactions, as well as from other precursors (e.g. phenol compounds, terpenes) present in the raw materials used. Three examples are given below but are far from being exhaustive. 

Determinations of isotope patterns by SNIF-NMR (see 6.2.2.3.2) are by far of more practical importance (for an early review see [317]). Although up to now this methodology is nearly exclusively limited to the elucidation of H-pattems, recent attempts for its extension to C-pattem determinations have been promising. Normally only pure substances are used for H-NMR measurements >150 mg sample and several hours scans are needed. In the present context NMR spectral data of aromatic compounds, terpenes and some aliphatic compounds have been compiled. 

GRAPE AROMA COMPOUNDS TERPENES, C13-NORISOPRENOIDS, BENZENE COMPOUNDS, AND 3-ALKYL-2-METHOXYPYRAZINES... 

Educt to be transformed Aromatic compound Terpene Alkaloids... 

Anisomyces odoratus has been reported to produce odoriferous simple aromatic compounds, terpenes and lanostadienoic acids (22). The unusual amino acid 2-amino-4-N-ureidopropionic acid and its oxalyl derivative were recently isolated from Coniophora puteana (23). 

Aminopropyltrimethoxysilane 2-(3,4-Epoxycyclohexyl) ethyltrimethoxysilane Formaldehyde/toluenesulfonamide polymer Glycidyl ether 100 Isocyanatopropyltriethoxysilane Mercaptopropyltrimethoxysilane Terpene resin Urea-formaldehyde resin adhesion promoter, concrete Diacetone acrylamide adhesion promoter, concrete-curing compounds Terpene resin... 

The extractives are a group of chemicals mainly consisting of organic waxes, oils, tannins, resins, fats, gums, carbohydrates, coloring matter and phenols. These chemicals exist as monomers, dimers, and polymers. In general, there are three types of wood extractives, namely, aliphatic compounds, terpenes and terpenoids, and phenolic compounds. 

Organic sulfur compounds such as sulfurized spermaceti oil, terpene sulfides, and aromatic disulfides have been used. Encumbered phenols such as di-tertiary-butylphenols and amines of the phenyl-alphanaphthylamine type are effective stopping the kinetic oxidation chain by creating stable radicals. 

Review Problem 2 This allyl bromide is an important intermediate in the synthesis of terpenes (including many flavouring and perfumery compounds), as the five carbon fi agment occurs widely in nature. How would you make it ... 

Strategy Problem 6 A labelled compound for biosynthetic studies. Mevaloitic acid (TM 418) is an intermediate in the biosynthesis of terpenes and steroids (Tedder, volume 4, p.217 ff). To study exactly what happens to each carbon atom during its transformation into, say, hmonene (418A), we need separate samples of mevalonic acid labelled with in each carbon atom in the molecule. This turns our normal strategy on its head since we must now look for one carbon discoimections. You can use reagents like Na CN, and... 

Terpenes are often referred to as isoprenoid compounds and are classified accord mg to the number of isoprene units they contain (Table 26 2)... 

Terpenes and related isoprenoid compounds are biosynthesized from isopentenyl pyrophosphate... 

Essential oils (Section 26 7) Pleasant smelling oils of plants consisting of mixtures of terpenes esters alcohols and other volatile organic substances Ester (Sections 4 1 and 20 1) Compound of the type... 

Terpenes (Section 26 7) Compounds that can be analyzed as clusters of isoprene units Terpenes with 10 carbons are classified as rnonoterpenes those with 15 are sesqmter penes those with 20 are diterpenes and those with 30 are tnterpenes... 

Sterols. Sterols (4) are tetracycHc compounds derived biologically from terpenes. They are fat-soluble and therefore are found in small quantities in fats and oils. Cholesterol [57-88-5] (4a) is a common constituent in animal fats such as lard, tallow, and butterfat. The hydroxyl group can be free or esterified with a fatty acid. 

Artificial materials include aUphatic, aromatic, and terpene compounds that are made synthetically as opposed to those isolated from natural sources. As an example, ben2aldehyde may be made synthetically or obtained from oil of bitter almond (51) and t-menthol may be made synthetically or isolated from oil of Mentha arvensis var. to give Bra2iUan mint oil or com mint oil. 

Phytoalexins are low molecular weight compounds produced in plants as a defense mechanism against microorganisms. They do, however, exhibit toxicity to humans and other animals in addition to microbes (30). Coumarins, glycoalkaloids, isocoumarins, isoflavonoids, linear furanocoumarins, stilbenes, and terpenes aU. fall into the category of phytoalexins (31). Because phytoalexins are natural components of plants, and because their concentration may increase as a response to production and management stimuli, it is useful to recogni2e the possible effects of phytoalexins in the human diet. 

Over the years, the term gums has been used to denote a wide range of compounds including polysaccharides, terpenes, proteins, and synthetic polymers. In the 1990s, the term more specifically denotes a group of industrially useful polysaccharides or their derivatives that hydrate in hot or cold water to form viscous solutions, dispersions, or gels (1). 

Hydrocarbons, compounds of carbon and hydrogen, are stmcturally classified as aromatic and aliphatic the latter includes alkanes (paraffins), alkenes (olefins), alkynes (acetylenes), and cycloparaffins. An example of a low molecular weight paraffin is methane [74-82-8], of an olefin, ethylene [74-85-1], of a cycloparaffin, cyclopentane [287-92-3], and of an aromatic, benzene [71-43-2]. Cmde petroleum oils [8002-05-9], which span a range of molecular weights of these compounds, excluding the very reactive olefins, have been classified according to their content as paraffinic, cycloparaffinic (naphthenic), or aromatic. The hydrocarbon class of terpenes is not discussed here. Terpenes, such as turpentine [8006-64-2] are found widely distributed in plants, and consist of repeating isoprene [78-79-5] units (see Isoprene Terpenoids). 

Chlorinated Terpenes. A group of incompletely characterized insecticidal compounds has been produced by the chlorination of the naturally occurring terpenes. Toxaphene [8001-35-2] is prepared by the chlorination of the bicycHc terpene, camphene [79-92-5] to contain 67—69% chlorine and has the empirical formula C QH QClg. The technical product is a yellowish, semicrystalline gum (mp 65—90°C, d 1.64) and is a mixture of 175 polychloro... 

The isoprene unit exists extensively in nature. It is found in terpenes, camphors, diterpenes (eg, abietic acid), vitamins A and K, chlorophyll, and other compounds isolated from animal and plant materials. The correct stmctural formula for isoprene was first proposed in 1884 (7). 

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