Terpenoids metabolites

That terpenoid metabolites can also be up-regulated in response to herbivory was demonstrated with the brown alga Dictyota menstrualis. The generalist amphipod Amphithoe longimana induced increased concentrations of the defensive diterpenes 65-67 in this alga, making it less palatable (Scheme 18). 

There has been much interest recently in terpenoid metabolites of marine organisms and two recent reports in this area describe the independent identification of the bromoeudesmane (298) as a constituent of red seaweed... 

The terpenoid metabolites reported from Dysidea sp. are predominantly sesquiterpenes [72]. They possess a spiro moiety as in herbadysidolide, Fig. (5), herbasolide, Fig (6) and spirodysin, Fig. (7), or they are fiiranosesquiterpenes such as furodysinin, Fig. (8). However, Dysidea herbacea from two collection sites on the Great Barrier Reef less than 120 km apart also yielded enantiomeric fiiranosesquiterpenes [73],... 

Dumdei, E. J., Kubanek, J., Coleman, J. E., Pika, J., Andersen, R. J., Steiner, J. R., and Clardy, J., New terpenoid metabolites from the skin extracts, an egg mass, and dietary sponges of the North Eastern Pacific dorid nudibranch Cadlina luteomarginata, Can. J. Chem., 75, 773, 1997. 

For nonpolar secondary metabolites (e.g., metabolites with no known primary function in the organism s physiology) from macroalgae, only two other studies (besides those on D. pulchra) are known in which care has been taken to test metabolite concentrations at ecologically realistic levels. The first is the study of Schmitt et al.17 for terpenoid metabolites from the brown alga Dictyota... 

The Hajos-Parrish reaction can be regarded as the enantioselective version of the Robinson annulation. In the early stages of the synthetic effort targeting the mixed polyketide-terpenoid metabolite (-)-austalide B, L.A. Paquette and co-workers used this transformation to prepare the key bicyclic precursor in enantiopure form. Ethyl vinyl ketone was reacted with 2-methyl-1,3-cyclopentanedione in the presence of catalytic amounts of L-valine to afford the bicyclic diketone with a 75% ee. 

Cleomeolide (91) is an unusual bicyclic diterpenoid obtained156 from Cleome viscosa (Capparaceae). The Basidiomycetes contain a number of unusual terpenoid metabolites such as the cyathins. These have now been thoroughly reviewed.157... 

Sesquiterpenoids related to eremophylane, synthesis of 80YGK783. Terpenoid metabolites of fungi and related basidiomycetes 81T2I99. 

The quaking aspen tree (Populus tremuloides) is a common tree in North America that is used for its timber. The wood-rotting pathogen Phellinus tre-mulae causes significant economic losses of this tree. Although the sesqui-terpenoid metabolites such as tremulenolide A (5.89) have a carbon skeleton that is isomeric with the lactaranes, some doubts have been expressed on its biosynthetic origin from farnesyl diphosphate. 

Terpenoid metabolites of mushrooms and related Basidiomycetes, W.A. Ayer and L.M. Browne, Tetrahedron, 1981, 37, 2199. 

Signal transduction enzyme inhibition assays guided the isolation of two novel hybrid polyketide-terpenoid metabolites from a Penicillium sp. growing in the deepest waters (>750 ft) of Berkeley Pit Lake [9], Their structures were deduced by spectroscopic analysis and confirmed by single crystal x-ray analysis on berkeleydione (13). Both compounds inhibited signal transduction enzymes caspase-1 and matrix metalloproteinase-3. Berkeleydione (13) was also active against non-small cell lung cancer in NCI s 60 cell line anti-tumor screen. 

No direct biosynthetic studies have been carried out on the sesquiterpenes from Eremophila. The difficulty of studying the biosynthesis of terpene metabolites of woody plants is well recognised and, until recently, little was known about the propagation of Eremophila species from seeds. Plant tissue cultures of many Eremophila species have been established, but an exhaustive examination of the metabolites produced by undifferentiated callus tissue failed to reveal the accummulation of terpenoid metabolites (86). The dominant metabolite found to be produced was the phenylpropanoid glycoside verbascoside, not previously detected in Eremophila species. Fatty acids and sterols were also produced. The formation of sterols may explain an earlier observation that tissue cultures of E. fraserii were capable of metabolising mevalonic acid (87). 

Recent studies have described the complex, constitutive, and MeJA- and insect-induced terpenoid defenses in Norway spruce and Sitka spruce at anatomical, chemical, and biochemical levels. " Miller et al. compared the effect of MeJA treatment and white pine weevil attack on induced terpenoid defenses in Sitka spruce. They found that MeJA and real insects induce very similar terpenoid responses at the biochemical and molecular levels. The cloning and functional characterization of a family of ten, functionally diverse Norway spruce TPS genes not only allowed an improved phylogeny of the conifer TPS-d gene family but also allowed a detailed molecular and biochemical characterization of induced changes in terpenoid metabolite profiles in spruce defense. Many of the products of the recently identified Norway spruce TPS genes correspond with components of terpenoid metabolite profiles after MeJA treatment or insect attack in species of spruce. Our work on Norway spruce terpenoid responses to MeJA treatment " is discussed here with an emphasis on those compounds that are products of the newly characterized spruce TPS genes. ... 

While the understanding of induced conifer terpenoid defenses has increased dramatically with much information now available from terpenoid metabolite profiling and the study of associated terpenoid pathways, there is still much to be... 

Ravi, B.N., and R.J. Wells Lipid and Terpenoid Metabolites of the Gorgonian Plexaura flava. Aust. J. Chem. 35, 105 (1982). 

Inspection shows that both chemically and biosynthetically the molecule can be divided into two parts a terpenoid nucleus and a decatetraenedioic acid side-chain related to normal fatty acids. The nucleus is not classically iso-prenoid, and could arise only in part through the now standard route for terpenoid metabolites from microorganisms, involving mevalonic acid (IV), itself derived from three molecules of acetyl coenzyme-A, Richards and Hendrickson (1964). The CHg of the methoxyl presumably arises from methionine. 

Ayer, W.A. and Browne, L.M. (1981) Terpenoid metabolites of mushrooms and related basidiomycetes. Tetrahedron, 2T7, 2199-2248. 

Dilip de Silva, E., Morris, S.A., Miao, S., Dumdei, E., and Andersen, R. J. (1991) Terpenoid metabolites from skin extracts of four Sri lanlcan nudibranchs in the genus Chromodoris. J. Nat. Prod., 54, 993-997. 

In their study of neutral, terpenoid metabolites from the Compositae, Bohlmann and his co-workers have discovered a series of dihydro-pyrrolizinone derivatives in Senecio species (Table 3 U). These are all macrocyclic diesters containing 12-membered rings, although it is interesting that macrocyclic diesters with both a and p stereochemistry at C-7 of the necine have been isolated. A related series of open chain esters, the senampelines (Table 3 T), have also been discovered. This work does indicate the need to carry out careful examination of both basic and neutral fractions from plant extracts when searching for pyrrolizidine derivatives. The extent of these new derivatives should also be ascertained by reinvestigating species of other families known to contain pyrrolizidine alkaloids. 

A comprehensive review of terpenoid metabolites of the Basidiomycetes has sections on the biosynthesis of these compounds. Many of the sesquiterpenoids found in these fungi can in theory be derived by various cyclizations of humulene. Conformational calculations on humulene have been made with a view to predicting the role of stable conformers in its biosynthetic reactions. 

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