Secondary metabolites biological activity

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... 

Phytochemicals are biologically-active, non-nutritive secondary metabolites which provide plants with colour, flavour and natural toxicity to pests. The classification of this huge range of compounds is still a matter of debate, but they fall into three main groups ... 

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 ... 

Marine sponges are a source of an array of polycyclic diamine alkaloids of common biogenetic origin. This class of secondary metabolites has been the subject of four previous reviews [4-7]. Therefore, the present review will include literature reports previously not discussed, dealing with the isolation, structure determination, biological activities, and total synthesis of polycycUc diamine alkaloids isolated from marine sponges. This review will not include guanidine alkaloids [8,9] or the manzamine alkaloids [10,11], since these compounds have been recently reviewed elsewhere. Only polycycUc... 

Application of Preparative Layer Chromatography for the Separation of Secondary Metabolites from Plant Tissues for Their Biological Activity Determination... 

Streptomyces strains are Gram positive [54], they have good secretion capacities and extensive fermentation knowledge has been accumulated. Mostly, they were used for the production of secondary metabolites with potent biological activities, such as antibiotics, immunosuppressors or pesticides. Constitutive [55] and inducible [56] expression is possible. Up to 40% of the total soluble cellular protein was reported in the case of inducible expression. 

Principle Plant enriched in secretory structures with biologically active secondary metabolites have fluorescing products in the cells and a location of the compounds could be observed using luminescent technique. 

An intramolecular cycloaddition also occurred with 3-ylidenepiperazine-2,5-diones such as 124 or 125, obtained by Wittig-Horner-Emmons reaction from phosphonate 121 and aldehydes 122 or 123, respectively. The products of the Diels-Alder reaction are the bridged bicyclo[2.2.2]diazaoctane rings 126 and 127 that have been found in biologically active secondary metabolite such as VM55599 and brevianamide A. The different type of structures employed in this case requires a chemoselective reaction in order to produce the expected products as single diastereoisomers after 20 days (Scheme 18) <2001JOC3984>. 

Lignans are secondary plant metabolites possessing a variety of biological activities [1,2]. They are dimers of phenylpropenes, which are by definition connected between C(8) and C(8 ) [3]. Lignans are of great structural variety due to numerous potential oxidation states at the C(7)/C(7 ) and C(9)/C(9 ) positions, and to the possibility of aryl-aryl bond formation [1-3]. 

Schulz B, Boyle C, Draeger S, Rommert AK, Krohn K, Endophytic fungi A source of novel biologically active secondary metabolites, MycolRes 106 996—1004,2002. 

The secondary metabolites of the endophytic fungi associated with dicotyledonous plants (dicots) are chemically diverse (Table 1). There is an equal diversity in the activities of these compounds, including antibacterial, antifungal, nematicidal, phytotoxic, cytotoxic, antineoplastic, anti-insectant, anti-herbivory, and a variety of other activities. The compounds isolated, structurally elucidated, and explored biologically in the short time since previous reviews continue to display that same wide array of chemical and biological diversity. 

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