Secondary metabolites chemistry

Roussis V, King RL, Fenical W (1993) Secondary metabolite chemistry of the Australian brown alga Encyothalia cliftonir. evidence for herbivore chemical defence. Phytochemistry 34 107-111... 

Schnitzler I, Boland W, Hay ME (1998) Organic sulfur compounds from Dictyopteris spp. deter feeding by an herbivorous amphipod (Ampithoe longimana) but not by a herbivorous sea urchin (Arbaciapimctulata). J Chem Ecol 24 1715-1732 Shen Y, T sai PI, Fenical W, Hay ME (1993) Secondary metabolite chemistry of the Caribbean marine alga Sporochnus bolleanus. a basis for herbivore chemical defense. Phytochemistry 32 71-75 Schupp PJ, Paul VJ (1994) Calcium carbonate and secondary metabolites in tropical seaweeds variable effects on herbivorous fishes. Ecology 75 1172-1185 Smit AJ (2004) Medicinal and pharmaceutical uses of seaweed natural products a review. J Appl Phycol 16 245-262... 

Shen, Y. C., Tsai, P. I., Fenical, W., and Hay, M. E., Secondary metabolite chemistry of the Caribbean marine alga Sporochnus bolleanus a basis for herbivore chemical defence, Phytochemistry, 32, 71, 1993. 

Terpenes are the predominant natural product in green macroalgae and diatoms and related groups.92 With the exception of an evaluation of VHOC production, for which these algae are only minor producers,147143 there have been no published investigations of their secondary metabolite chemistry from Antarctic regions. 

The secondary metabolite chemistry of molluscs often reflects their diet since many molluscs have evolved the ability to sequester dietary metabolites for their own defense. This led to the... 

Only one report of Antarctic soft coral secondary metabolite chemistry has appeared in the literature. As described above, the stoloniferan coral Clavularia frankliniana has been demonstrated to produce fatty glyceride esters, chimyl alcohol (Structure 7.79) in particular, that are also found in its predator, the nudibranch Tritoniella belli.44 Chimyl alcohol has been investigated in ecological bioassays and has been implicated in deterring predation by the omnivorous sea star Odontaster validus.44... 

Pichiafurans A-C (98—100) and pichiacins A (101) and B (102) have been characterized from the yeast Pichia membranifaciens, which was obtained from the Korean marine sponge Petrosia sp. So far, no marine isolates of the genus Pichia had been described, and this yeast had not been studied with regard to its secondary metabolite chemistry. Compounds 98—100 are friryl ethers with 2-phenylethanol, while 101 and 102 are esters consisting of 2-phenylethanol and short-chain w-hydroxy acids. 

Abdel-Wahab, M.A., Asolkar, R.N., Inderbitein, P., and FenicaL W. (2007) Secondary metabolite chemistry of the marine-derived fungus Massarina sp strain CNT-016. Phytochemistry, 68,1212-1218. 

Application of NMR spectroscopy to heterocyclic chemistry has developed very rapidly during the past 15 years, and the technique is now used almost as routinely as H NMR spectroscopy. There are four main areas of application of interest to the heterocyclic chemist (i) elucidation of structure, where the method can be particularly valuable for complex natural products such as alkaloids and carbohydrate antibiotics (ii) stereochemical studies, especially conformational analysis of saturated heterocyclic systems (iii) the correlation of various theoretical aspects of structure and electronic distribution with chemical shifts, coupling constants and other NMR derived parameters and (iv) the unravelling of biosynthetic pathways to natural products, where, in contrast to related studies with " C-labelled precursors, stepwise degradation of the secondary metabolite is usually unnecessary. 

The held of marine natural products chemistry, which encompasses the study of the chemical structures and biological activities of secondary metabolites produced by marine plants, animals, and microorganisms, began in earnest in the early 1960s. " This is in stark contrast to the study of terrestrial plant natural... 

The underlying assumption driving marine natural products chemistry research is that secondary metabolites produced by marine plants, animals, and microorganisms will be substantially different from those found in traditional terrestrial sources simply because marine life forms are very different from terrestrial life forms and the habitats which they occupy present very different physiological and ecological challenges. The expectation is that marine organisms will utilize completely unique biosynthetic pathways or exploit unique variations on well established pathways. The marine natural products chemistry research conducted to date has provided many examples that support these expectations. 

With remarkable accuracy, Democritus in the fifth century B.C. set the stage for modem chemistry. His atomic theory of matter, which he formulated without experimental verification, still stands, more or less intact, and encapsulates the profound truth that nature s stunning wealth boils down to atoms and molecules. As science uncovers the mysteries of the world around us, we stand ever more in awe of nature s ingenious molecular designs and biological systems nucleic acids, saccharides, proteins, and secondary metabolites are four classes of wondrous molecules that nature synthesizes with remarkable ease, and uses with admirable precision in the assembly and function of living systems. 

Epoxides are often encountered in nature, both as intermediates in key biosynthetic pathways and as secondary metabolites. The selective epoxidation of squa-lene, resulting in 2,3-squalene oxide, for example, is the prelude to the remarkable olefin oligomerization cascade that creates the steroid nucleus [7]. Tetrahydrodiols, the ultimate products of metabolism of polycyclic aromatic hydrocarbons, bind to the nucleic acids of mammalian cells and are implicated in carcinogenesis [8], In organic synthesis, epoxides are invaluable building blocks for introduction of diverse functionality into the hydrocarbon backbone in a 1,2-fashion. It is therefore not surprising that chemistry of epoxides has received much attention [9]. 

The discovery that, in industrialised societies, diets deficient in fruits and vegetables can effectively double the risk of developing many different types of cancer has focused renewed attention on the beneficial properties of these foods (Block e/a/., 1992 Patterson ef a/., 1990 Southon and Faulks, 2002). As we have seen, plant foods are rich in micronutrients, but they also contain an immense variety of biologically active secondary metabolites providing colour, flavour and natural toxicity to pests and sometimes humans (Johnson et ah, 1994). The chemistry and classification of such substances is still a matter for much research and debate, but this has not prevented attempts to isolate and exploit substances that have variously been termed protective factors , phytoprotectants , phytochemicals and nutraceuticals . Phytochemical compounds include ... 

Secondary Metabolites (All s Fair in Love War). Biological Chemistry—Lecture 5, Wayne Best, University of Western Australia, http //www.cygnus.uwa.edu.au/ wmbest/biolchem/lecture-05.pdf... 

It is well established that the principal source of secondary metabolites in marine molluscs resides in the sometimes selective concentration of chemicals contained in their food. The chemical connection between molluscan predator and its algal or invertebrate diet has been confirmed as a result of many investigations of the chemistry of herbivorous [6] and carnivorous [3] molluscs and their dietary sources. However, the assumption often reported, as in a recent review [7], that marine molluscs invariably obtain their metabolites from dietary sources, should be regarded as an oversimplification. In fact, active biosynthesis of secondary metabolites has been ascertained in several cases, as documented here. 

FUJII, I., Polyketide biosynthesis in filamentous fungi. In Comprehensive Natural Products Chemistry, Vol. 1, Polyketides and Other Secondary Metabolites Including Fatty Acids and Their Derivatives (U. Sankawa ed.), Elsevier, Amersterdam, 1999, pp. 409-441. 

Secondary chemistry differs from primary chemistry principally in its distributional variability and it is this variability that has intrigued ecologists for the past 30 years. Theories [or provisional hypotheses (35)] to account for the structural differentiation and function of secondary metabolites, as well as the differential allocation of energy and materials to defensive chemistry, abound, but they are almost exclusively derived from studies of plant-herbivore interactions (Table 2). This emphasis may be because the function of secondary chemicals in plants is less immediately apparent to humans, who have historically consumed a broad array of plants without ill effects, so alternative explanations of their presence readily come to mind. The fact that animals upon disturbance often squirt, dribble, spray, or otherwise release noxious substances at humans and cause pain leads to readier acceptance of a defensive function [although there are skeptics who are unconvinced of a... 

Chlorophyta or green algae comprise one of the major groups of algae and include several exclusively marine orders and genera from tropical regions. Natural products chemistry research has identified more than 300 secondary metabolites from Chlorophyta, with most being sesquiterpenoid and diterpenoid compounds... 

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