Terpenes diterpene acids

Methyl jasmonate treatment not only triggers a dramatic change in terpene quantity, but also causes changes in terpene composition. For example, of the two major monoterpenes in the wood, a-pinene and P-pinene, the proportion of a-pinene to P-pinene changed from about 1 1 in control saplings to 1 2 after methyl jasmonate treatment, with increases in the relative amounts of the (-)-enantiomers in relation to the (+)-enantiomers of both compounds. Among the diterpenes, levopimaric acid increased over 5-fold after methyl jasmonate treatment in comparison to a 2.5-fold increase in most of the other major diterpene acids. 

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). 

We focused our attention on Tall oil, a by-product of the paper industry, whenever this is prepared according to the KRAFT process. Said material consists of a mixture of highly unsaturated fatty acids (many of which with conjugated diene systems) and terpene derived rosin acids. The rosin acids have the molecular formula C20H30O2 and thus belong to the diterpenes (pimaric and abietic acids). Tall Oil has an iodine number equal to approximately 170 gl2/100 g. 

Examples of other antimicrobial diterpenoids from the Anthemideae tribe also included a nor-ent-kaurane diterpene, Fig. (26) from the aerial parts of Antennaria geyeri L. [196], three new diterpenes jasonin A-C isolated from the aerial parts of Jasonia montana [206] and the terpenes 15-hydroxy-7-labden-17-oic acid, Fig. (27) and their acetate from Eupatorium glutinosum Matico, which were active against 2 Gram (-) and 2 Gram (-I-) bacteria [207,208]. 

Terpenes are are a class of compounds whose chemical structures are based on a number of isoprene units , derived from the hydrocarbon CH2=C(CH3)-CH=CH2 they may themselves be hydrocarbons, but may also contain alcohol (OH), aldehyde/ketone (CO) and carboxylic acid (COOH) groups. Monoterpenes are Cm compounds derived from two isoprene units, sesquiterpenes (Cu) are derived from three isoprene units, diterpenes (C20) from four and tritepenes (C30) from six. Terpenes are widespread in plants, where they are largely responsible for the odor, and they are the major constituents of plant-derived essential oUs . Among the best known terpenes are 3-pinene (turpentine), camphor, menthol and citroneUal (aU monoterpenes) and farnesol (a sesquiterpene that is a constituent of the essential oils of many plants). Certain terpenes have important biological roles vitamin A, for example, is a diterpene, and steroid hormones have a structure related to triterpenes (and are biosynthesized by a similar route). 

This c20 pyrophosphate (122), C20H36O7P2, is thought to provide the carbon framework of the diterpene alkaloids such as veatchine (123), atisine (124), and aconitine (125) (Fig. 5). It is not known at what stage the nitrogen is incorporated into the framework established by the skeleton. The potential for terpene rearrangements and the observation that the alkaloids are frequendy found esterified, often by acetic or benzoic acid, as well as free, has led to permutations and combinations producing over 100 such compounds. 

H) Perovskone A Diels—Alder reaction between different types of terpene units is plausible in several cases. Perovskone (55) from the heartwood of Chamaecyparis obtuse s regarded as an adduct between a chiral quinone 53 derived from an abietane-type diterpene (similar to that of grandione) and the linear monoterpene trans-j3-ocimene as shown in Scheme 12. In the total synthesis of perovskone, the Diels-Alder reaction of 53 and trawr-a-ocimene with Lewis acid Eu(fod)3 proceeded in good regio- and... 

The dramatic increase in terpene formation, accumulation, and emission in P. abies in response to methyl jasmonate is consistent with the effect of methyl jasmonate or jasmonic acid on many defense compounds in angiosperms. In conifers, jasmonates had been previously shown to promote the formation of heat shock and defense signaling proteins, to enhance resistance to pathogenic fimgi, and to promote colonization with ectomycorrhizae. In relation to terpenes, jasmonates had been shown to promote formation of an oxygenated sesquiterpene, todomatuic acid, and an oxygenated diterpene, paclitaxel (taxol), in cell cultures, but had never before been reported to enhance terpene accumulation in intact plants. 

ABSTRACT The Wieland-Miescher ketone (1) and its methyl analog (2) have been utilized for the synthesis of several sesquiterpenes like warburganal, muzigadial, albicanol, etc. Similarly several bioactive diterpenes like taxodione, pisiferic acid, aphidicolin, etc., have been synthesized from these ketones. The utility of several reagents in the total synthesis of terpenoid compounds has been documented. The developments of several routes for a single terpene from these ketones have been discussed. 

There are a number of branches between MVA and ent-kaurene that lead to biologically important terpenes other than the gibberellins for example, in plants, a branch at IPP leads to the side chain of cytokinins a branch at FPP leads to squalene and the sterols, also abscisic acid branches at GGPP lead to phytoene, fatty acid esters, chlorophyll esters and non-cyclic diterpenes and branches at CPF lead to (-)-trachylobane, (-f)-beyerene, ( f)-sandaracopiinaradiene (21) and ent-isokaurene (22). (For a review of the pathway to ent-kaurene see reference 23). 

Terpenes are classified according to the number of carbon atoms, in units of ten. A terpene with 10 carbon atoms (two isoprene units) is called a monoterpene, one with 20 carbon atoms (four isoprene units) is a diterpene, and so oa Teipenes with 15 carbon atoms (three isoprene units) are called sesquiterpenes, meaning that they have 11 times 10 carbon atoms. Myrcene, geranial, menthol, and camphor are monoterpenes, /3-selinene is a sesquiterpene, abietic acid is a diterpene, and squalene (Figure 25-12) is a triterpene. 

Erythrophleum alkaloids a group of terpene alkaloids from Erythrophleum guineense and E. ivor-ense. They are esters or amides of the diterpene cas-sainic acid with substituted ethanolamines. The most important is cassaine (Fig.), a cardiotonic agent equal in potency to the digitalis glycosides. 

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