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Potent Biological Activity (potent + biological_activity)
Selected AbstractsAntioxidant and other biological activities of phenols from olives and olive oilMEDICINAL RESEARCH REVIEWS, Issue 1 2002Francesco Visioli Abstract Olive oil is the principal source of fats in the Mediterranean diet, which has been associated with a lower incidence of coronary heart disease and certain cancers. Phenolic compounds, e.g., hydroxytyrosol and oleuropein, in extra-virgin olive oil are responsible for its peculiar pungent taste and for its high stability. Recent findings demonstrate that olive oil phenolics are powerful antioxidants, both in vitro and in vivo, and possess other potent biological activities that could partially account for the observed healthful effects of the Mediterranean diet. © 2001 John Wiley & Sons, Inc. Med Res Rev, 22, No. 1, 65,75, 2002 [source] Biosynthetic studies of the DSP toxin skeletonTHE CHEMICAL RECORD, Issue 1 2004Antonio H. Daranas Abstract Marine toxins have drawn wide interest because their economical impact and disastrous effect upon the shellfish industry and public health in many parts of the world. One of the most interesting group of substances of marine toxins, from structural and pharmacological points of view are polyether compounds, which generally present a great diversity in size and potent biological activities. The subject of this work was about to biosynthesis of okadaic acid skeleton as leader as DSP toxins. Its biosynthesis attracts considerable attention since the carbon skeleton has been shown to be synthesised via an unusual route. In this paper we report on stable isotope incorporation experiments on DSP toxin in artificial cultures of dinoflagellate. The comparison of the degrees of incorporation in these samples measured by different methods led to contradictory results. This implies that further experimental data is needed in order to propose a logical biogenetic scheme. © 2004 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 4: 1,9; 2004: Published online in Wiley InterScience (www.interscience.wiley.com ) DOI 10.1002/tcr.10072 [source] Synthesis and Biological Evaluation of Pretubulysin and Derivatives,EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 36 2009Angelika Ullrich Abstract Pretubulysin, a biosynthetic precursor of the tubulysins, shows potent biological activity in the subnanomolar range towards various tumor cell lines. Its activity is only slightly less than those of the structurally more complex tubulysins. With a straightforward synthesis to hand, pretubulysin is an ideal lead structure for the development of tubulysin-based anticancer drugs(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Oxylipin studies expose aspirin as antifungalFEMS YEAST RESEARCH, Issue 8 2007Johan L. F. Kock Abstract The presence of aspirin-sensitive 3-hydroxy fatty acids (i.e. 3-OH oxylipins) in yeasts was first reported in the early 1990s. Since then, these oxidized fatty acids have been found to be widely distributed in yeasts. 3-OH oxylipins may: (1) have potent biological activity in mammalian cells; (2) act as antifungals; and (3) assist during forced spore release from enclosed sexual cells (asci). A link between 3-OH oxylipin production, mitochondria and aspirin sensitivity exists. Research suggests that: (1) 3-OH oxylipins in some yeasts are probably also produced by mitochondria through incomplete ,-oxidation; (2) aspirin inhibits mitochondrial ,-oxidation and 3-OH oxylipin production; (3) yeast sexual stages, which are probably more dependent on mitochondrial activity, are also characterized by higher 3-OH oxylipin levels as compared to asexual stages; (4) yeast sexual developmental stages as well as cell adherence/flocculation are more sensitive to aspirin than corresponding asexual growth stages; and (5) mitochondrion-dependent asexual yeast cells with a strict aerobic metabolism are more sensitive to aspirin than those that can also produce energy through an alternative anaerobic glycolytic fermentative pathway in which mitochondria are not involved. This review interprets a wide network of studies that reveal aspirin to be a novel antifungal. [source] Rationally designed mutations convert complexes of human recombinant T cell receptor ligands into monomers that retain biological activityJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 1 2005Jianya Y Huan Abstract Single-chain human recombinant T cell receptor ligands derived from the peptide binding/TCR recognition domain of human HLA-DR2b (DRA*0101/DRB1*1501) produced in Escherichia coli with and without amino-terminal extensions containing antigenic peptides have been described previously. While molecules with the native sequence retained biological activity, they formed higher order aggregates in solution. In this study, we used site-directed mutagenesis to modify the ,-sheet platform of the DR2-derived RTLs, obtaining two variants that were monomeric in solution by replacing hydrophobic residues with polar (serine) or charged (aspartic acid) residues. Size exclusion chromatography and dynamic light scattering demonstrated that the modified RTLs were monomeric in solution, and structural characterization using circular dichroism demonstrated the highly ordered secondary structure of the RTLs. Peptide binding to the ,empty' RTLs was quantified using biotinylated peptides, and functional studies showed that the modified RTLs containing covalently tethered peptides were able to inhibit antigen-specific T cell proliferation in vitro, as well as suppress experimental autoimmune encephalomyelitis in vivo. These studies demonstrated that RTLs encoding the Ag-binding/TCR recognition domain of MHC class II molecules are innately very robust structures, capable of retaining potent biological activity separate from the Ig-fold domains of the progenitor class II structure, with prevention of aggregation accomplished by modification of an exposed surface that was buried in the progenitor structure. Copyright © 2004 Society of Chemical Industry [source] The evolution of secondary metabolism , a unifying modelMOLECULAR MICROBIOLOGY, Issue 5 2000Richard D. Firn Why do microbes make secondary products? That question has been the subject of intense debate for many decades. There are two extreme opinions. Some argue that most secondary metabolites play no role in increasing the fitness of an organism. The opposite view, now widely held, is that every secondary metabolite is made because it possesses (or did possess at some stage in evolution) a biological activity that endows the producer with increased fitness. These opposing views can be reconciled by recognizing that, because of the principles governing molecular interactions, potent biological activity is a rare property for any molecule to possess. Consequently, in order for an organism to evolve the rare potent, biologically active molecule, a great many chemical structures have to be generated, most of which will possess no useful biological activity. Thus, the two sides of the debate about the role and evolution of secondary metabolism can be accommodated within the view that the possession of secondary metabolism can enhance fitness, but that many products of secondary metabolism will not enhance the fitness of the producer. It is proposed that secondary metabolism will have evolved such that traits that optimize the production and retention of chemical diversity at minimum cost will have been selected. Evidence exists for some of these predicted traits. Opportunities now exist to exploit these unique properties of secondary metabolism to enhance secondary product diversity and to devise new strategies for biotransformation and bioremediation. [source] | |||||||||||||