Macrocyclic diterpene

Perkins, D. L., and L. S. Ciereszko. Effect of macrocyclic diterpene from tobacco on Tetrahymena pyriformis. 

Carbonylative coupling of vinyl triflates with organotins (12, 470-471).3 The final step in a synthesis of the macrocyclic diterpene jatrophone (2) was effected by carbonylative coupling of a vinyl triflate with vinyltin catalyzed by bis(acetonitrile)-dichloropalladium. 

Dudley, M.W., Dueber, M.T. and West, C.A. (1986) Biosynthesis of the macrocyclic diterpene casbene in castor bean (Ricinus communis L.) seedlings changes in enzyme levels induced by fungal infection and intracellular localization of the pathway. Plant Physiol., 81, 335-42. 

Pborbol and Its Relatives.— The Euphorbiaceae are a rich source of diterpenes. The hydrocarbon casbene (126), which is clearly related to the macrocyclic diterpene cembrene, has been isolated from Ricinus communis It may also be related to the parent hydrocarbon of the phorbol group of diterpenoids. 

The Taxane Diterpenes.— The taxane skeleton represents an alternative mode of cyclisation of the macrocyclic diterpene hydrocarbon. Seven new taxane derivatives have been isolatedfrom Taxus baccata and characterised on the basis of spectroscopic and other data. Their structures are summarised in the following formulae (136a—g). In addition, the structure of baccatin-III (137), one of a group of complex esters isolated from the same source, has been com-pleted. The application of the olefin Octant rule to the taxane A double bond leads to the absolute configuration of these diterpenes. 

The herb Cleome viscosa (syn. cleome icosandra)y which is widely distributed in India, has long been recognized by the native population to serve as a rubefaciant, vesicant, and anthelmintic agent. As a consequence of these reputed properties, three research groups undertook almost simultaneously in the late 1970 s to determine the principal active constituent of this sticky, odoriferous plant [82,83]. On the basis of the NMR, X-ray, and CD data, the substance was determined to be the macrocyclic diterpene lactone 160 and named cleomeolide. The structural features of this macrolide are unusual in several respects (a) the double bond positioned a,p to the lactone carbonyl resides at a bridgehead site, a... 

Roberts, D.L. and J.N. Schumacher Isolation and characterization of compound XL A macrocyclic diterpene 3238. 

Rowland, R.L. and D.L. Roberts Macrocycylic diterpenes isolated from tobacco, a- and P-3,8,13-Duvatriene-1,5-diols J. Org. Chem. 28 (1963) 1165-1169. Rowland, R.L., A. Rodgman, J.N. Schumacher, D.L. Roberts, L.C. Cook, and W.E. Walker Jr Macrocyclic diterpenes. Hydroxyethers from tobacco and tobacco smoke 17th Tobacco Chemists Research Conference, Program Booklet and Abstracts, Vol. 17, Paper No. 16, 1963, p. 13, for presentation text, see www.rjrtdocs.com 521189981 -9997 Macrocyclic diterpene hydroxyethers from tobacco and cigarette smoke J. Org. Chem. 29... 

Cembranoids The first macrocyclic diterpene isolated from an Eremophila species was the triol (99) produced by E. clarkei (96). The resin obtained from this plant was a complex mixture of compounds from which the crystalline triol could be obtained with difficulty from the neutral fraction. Larger quantities of triol were available after methylation and lithium aluminium hydride reduction of the acidic fraction. The plane structure of 99 was established by conversion of the triol to a crystalline stereoisomer of cembrane (100) as shown in Scheme 25. The two dihydrotriols (101 and 102) obtained in this sequence also served to prove the location of the hydioxymethylene groups on the cembrane skeleton. Since both 101 and 102 are optically active, the symmetrical 4,12-cis arrangement of the primary alcohol groups can be excluded. Furthermore, the 4, 2-trans-disposition of these groups can also be excluded since elimination of the asymmetry at Cl leads to two different olefins (103 and 104). 

The macrocyclic diterpene lactone, cleomeolide (1) was first isolated by us [9,10] in the late 1970s and its complete structure and stereochemistry were determined by means of NMR, X-ray and CD methods. Burke et al. 

C20H24O3, Mr 312.41, needles, mp. 152-153°C, [a] +292° (C2H5OH). A macrocyclic diterpene of the jatro-phane type from Jatropha gossypiifolia (Euphorbia-ceae). In animal experiments J. is active against various types of cancer. Ifi-Hydroxy-J. (C20H24O4, Mr 328.41) and 2a-hydroxy-J. tom the roots of the same... 

In addition to the macrocyclic diterpenes previously reported, soldiers of Cubitermes umbratus (subfamily Termitinae) produce a novel diterpene, bif 1 ora-4,10 19),15-triene (32). Three investigations of members of the more primitive family Rhinotermitidae further illustrate the biosynthetic diversity of this group. Two... 

Diterpenes are a structurally diverse class of C20 natural compounds, widely distributed in nature and originating by condensation of four isoprene units derived from mevalonate or deoxyxylulose phosphate pathways. The latter, recently discovered, originates the diterpene compounds in plants. Diterpenes can be classified as Unear, bicyclic, tricyclic or tetracyclic, pentacyclic, and macrocyclic diterpenes depending on their skeletal core. In nature, they are commonly found in a polyoxygenated form with keto and hydroxyl groups, these last often esterified by small-sized aliphatic or aromatic acids. 

Diterpenes are a heterogeneous class of natural compounds based on 20 carbon atoms. They are widely distributed in nature, both in terrestrial and marine organisms, and originate by condensation of four isoprene units derived from mevalonate or deoxyxylulose phosphate [1] pathways, wherein the latter pathway was recently discovered taking place in the biosynthesis of diterpene compounds in plants [2]. As for other classes of natural compounds diterpenes have shown an importance as biomarker of certain species, thus contributing to their chemotaxonomy classification [3]. For example, macrocyclic diterpenes and their cyclization products have been isolated only from Euphorbiae plants of which they could be considered as biomarker [4]. Although thousands of diterpene compounds have been described in nature from terrestrial and marine organisms, only few of them became clinically effective [5]. Active compounds isolated from plants are used directly in therapy or... 

Barile E, Fattorusso E, lalenti A, lanaro A, Lanzotti V (2007) Bioorg Med Chem Lett 17 4196 Barile E, Lanzotti V (2007) Biogenetical related highly oxygenated macrocyclic diterpenes from sea spmge Euphorbia paralias. Org Lett 9 3603... 

Karlsson B, Pilotti A M, Soderholm A C, Norin T, Sundin S, Sumimoto M 1978 Structure and absolute configuration of verticillol, a macrocyclic diterpene alcohol from the wood of Sciadopi-tys verticillata Sieb. et Zucc. (Taxodiaceae). Tetrahedron 34 2349-2354... 

In a paper discussing strategies for the synthesis of the macrocyclic diterpene jatrophone, brief comment is made disclosing that chromous sulphate can cleanly effect the stereospecific reduction of a-oxoacetylenes to the corresponding E-enone, analogous to the reduction of acetylenic alcohols." ... 

Shizuri Y, Ohtsuka J, Kosemura S, Terada Y, Yamamura S. Biomimetic reactions of some macrocyclic diterpenes. Tetrahedron Lett. 1984 25 5547-5550. 

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