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Alcohols diterpenic

Mostly, terpenoids originate from plants, but they are also synthesized by other organisms, including yeast and bacteria, as primary or secondary metabolites. Terpenoids are S5mthesized from two 5-car-bon building blocks that consist of isoprenoid units [62]. Based on the number of building blocks, terpenoids have been classified into four classes monoterpenes (geraniol, carvone, d-limonene, and perillyl alcohol), diterpenes (retinol and trans-retinoic acid), triterpenes (lupeol, oleanic acid, betulinic acid, and ursolic acid), and tetraterpenes (lutein, a-carotene, yS-carotene, and lycopene) [66]. [Pg.71]

Diterpenic alcohols Diterpenic alcohols are present in nature as free compounds or bound in fatty acid esters and glycosides. They have no significance as flavourings, but may be precursors of flavour-active products. A number of diterpenoids are biologically active substances. Diterpenic alcohols known as gibberellins are found universally in plant tissues, and act as plant hormones. [Pg.531]

C2oH4qO- a diterpenic alcohol obtained by the action of alkalis on chlorophyll. Colourless oil b.p. 202-204 C/lOmm. On oxidation it yields a ketone CigHsoO b.p. 175 "C/l I mm. phytoxic Poisonous to plants. [Pg.313]

Terpenes are characterized as being made up of units of isoprene in a head-to-tail orientation. This isoprene concept, invented to aid in the stmcture deterrnination of terpenes found in natural products, was especially useful for elucidation of stmctures of more complex sesquiterpenes, diterpenes, and polyterpenes. The hydrocarbon, myrcene, and the terpene alcohol, a-terpineol, can be considered as being made up of two isoprene units in such a head-to-tail orientation (1). [Pg.408]

Chemistry of rosin. All three types of rosin consist primarily of C20 mono-carboxylic diterpene resin acids, the most common of which have the molecular formula C20H20O2. In addition, rosins contain small amounts of neutral and other acidic components (e.g. fatty acids in tall oil rosin). The neutral components of rosins are diterpene alcohols, hydrocarbons and aldehydes, and their contents generally vary between 5 and 15 wt%. [Pg.599]

Provided that the silanolate elimination proceeds with anti selectivity, it must be concluded, that the intermediate homoallylic alcohol has an anti configuration, and thus the reagent has an ( -configuration. Acidic hydrolysis of the enol ether leads to enones the overall sequence consists of a nucleophilic acroylation. This has also been applied in the total synthesis of the marine diterpene ( )-aplysin-2067. [Pg.413]

Large amounts of diterpene mono- and di-alcohols have been found in both Arabic and Robusta coffees, including cafestol, kahweol, and 16-O-methylcafestol.126 The characteristic differences can be used to quantify the Robusta content of commercial blends with Arabica.127... [Pg.145]

Arabica/Robusta beans used in different countries ranges from 1.5 1 in Italy, 4 1 to 3 1 in the U.S., and 20 1 in Sweden and Norway.2 As described in Chapter 6, coffee contains a number of physiologically active components, including caffeine, diterpene alcohols, sterols, hydrocarbons, squalene, and others. [Pg.307]

The biosynthesis of monoterpenes, the major components of peppermint essential oils, can be divided into four stages (Fig. 9.4). Stage 1 includes the formation of isopentenyl diphosphate (IPP) and dimethylallyl alcohol (DMAPP). In plants, two separate pathways are utilized for the synthesis of these universal C5 intermediates, with the cytosolic mevalonate pathway being responsible for the formation of sterols and certain sesquiterpenes, and the plastidial mevalonate-independent pathway being involved in the biosynthesis of isoprene, monoterpenes, certain sesquiterpenes, diterpenes, tetraterpenes, as well as the side chains of chlorophyll and plastoquinone.16 In peppermint oil gland secretory cells, however, the mevalonate pathway is blocked and the biosynthesis of monoterpenoid essential... [Pg.149]

In particular, substrates like terpene alcohols are often used with Candida rugosa with very high enantiomeric excesses and at high yields. Lee et al. could increase significantly the maximum reaction velocity of this lipase in AOT-based reverse micelles and obtained conversions up to 70% during the esterification of diterpenes alcohols (geraniol, menthol, citronellol) [130]. [Pg.204]

Essential oils may comprise volatile compounds of terpenoid or non-terpe-noid origin. All of them are hydrocarbons and their oxygenated derivatives. Some may also contain nitrogen or sulphur derivatives. They may exist in the form of alcohols, acids, esters, epoxides, aldehydes, ketones, amines, sulphides, etc. Monoterpenes, sesquiterpenes and even diterpenes constitute the composition of many essential oils. In addition, phenylpropanoids, fatty acids and their esters, or their decomposition products are also encountered as volatiles [1-16, 21-33, 36-38]. [Pg.43]

Phytol, a diterpene alcohol (3,7,11,15-tetramethyl-2-hexadecen-l-ol), occurs in two isomeric forms fraus-phytol 110 and czs-phytol 111 (Structure 4.33). Phytol was first isolated at the beginning of the nineteenth century during esterification of the chlorophyll molecule. It is a constituent of nettle and many essential oils. Another acyclic diterpene, geranylcitronellol 112, also occurs in essential oils. [Pg.61]

C15H24) and diterpenes (C20H32), and oxygenated hydrocarbons such as alcohols, esters, aldehydes, ketones, ethers, and phenols. [Pg.548]

Two important diterpene alcohols are vitamin A (Section 28-7) and phytol, which occurs as an ester of the propanoic acid side-chain of chlorophyll (Figure 20-6) ... [Pg.1468]


See other pages where Alcohols diterpenic is mentioned: [Pg.67]    [Pg.52]    [Pg.232]    [Pg.67]    [Pg.52]    [Pg.232]    [Pg.386]    [Pg.205]    [Pg.143]    [Pg.165]    [Pg.334]    [Pg.354]    [Pg.70]    [Pg.45]    [Pg.69]    [Pg.76]    [Pg.164]    [Pg.219]    [Pg.221]    [Pg.122]    [Pg.166]    [Pg.167]    [Pg.116]    [Pg.139]    [Pg.140]    [Pg.147]    [Pg.174]    [Pg.214]    [Pg.236]    [Pg.146]    [Pg.553]    [Pg.200]    [Pg.276]    [Pg.180]    [Pg.66]    [Pg.923]   
See also in sourсe #XX -- [ Pg.519 ]




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