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Biological Interest (biological + interest)
Selected AbstractsChemInform Abstract: Microwave-Assisted, Solvent-Free, Parallel Syntheses and Elucidation of Reaction Mechanism for the Formation of Some Novel Tetraaryl Imidazoles of Biological Interest.CHEMINFORM, Issue 37 2009B. R. Prashantha Kumar Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Synthesis of Novel 3-Substituted Coumarin Carboxamides with Biological Interest and Their Spectral Studies.CHEMINFORM, Issue 25 2009Asish R. Das Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] 2-[4-(2-Thienyl)-1,3-thiazol-2-yl]ethanenitrile in Heterocyclic Synthesis of Biological Interest.CHEMINFORM, Issue 48 2005Abdou O. Abdelhamid Abstract For Abstract see ChemInform Abstract in Full Text. [source] Alkoxy-5-nitrosopyrimidines: Useful Building Block for the Generation of Biologically Active CompoundsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 20 2010Antonio Marchal Abstract Several alkoxy-5-nitrosopyrimidines were synthesised and high regioselective and sequential nucleophilic aromatic substitution of methoxy groups in 2-amino-4,6-dimethoxy-5-nitrosopyrimidine was observed. The approach was applied to the synthesis of valuable polyfunctionalised aminopyrimidines capable of mimicking fused heterobicyclic derivatives of biological interest. In addition, new compounds were evaluated as antivirals and their usefulness as synthetic intermediates was demonstrated. [source] Thiols in Ugi- and Passerini,Smiles-Type CouplingsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 35 2008Anaëlle Barthelon Abstract The use of the Smiles rearrangement in Ugi-type couplings with aromatic mercaptans allows for the straightforward, multicomponent formation of ,-arylamino thiocarboxamides. The scope of this new four-component coupling is further broadened with the use of heterocyclic mercapto derivatives that afford thioamides of high biological interest in one step. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Nucleotide-binding domain 1 of cystic fibrosis transmembrane conductance regulatorFEBS JOURNAL, Issue 17 2000Production of a suitable protein for structural studies Cystic fibrosis is caused by mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR). This protein belongs to the large ATP-binding cassette (ABC) family of transporters. Most patients with cystic fibrosis bear a mutation in the nucleotide-binding domain 1 (NBD1) of CFTR, which plays a key role in the activation of the channel function of CFTR. Determination of the three dimensional structure of NBD1 is essential to better understand its structure,function relationship, and relate it to the biological features of CFTR. In this paper, we report the first preparation of recombinant His-tagged NBD1, as a soluble, stable and isolated domain. The method avoids the use of renaturing processes or fusion constructs. ATPase activity assays show that the recombinant domain is functional. Using tryptophan intrinsic fluorescence, we point out that the local conformation, in the region of the most frequent mutation ,F508, could differ from that of the nucleotide-binding subunit of histidine permease, the only available ABC structure. We have undertaken three dimensional structure determination of NBD1, and the first two dimensional 15N- 1H NMR spectra demonstrate that the domain is folded. The method should be applicable to the structural studies of NBD2 or of other NBDs from different ABC proteins of major biological interest, such as multidrug resistance protein 1 or multidrug resistance associated protein 1. [source] Behavior and physiology of mechanoreception: separating signal and noiseINTEGRATIVE ZOOLOGY (ELECTRONIC), Issue 1 2009John C. MONTGOMERY Abstract The mechanosensory lateral line is found in all aquatic fish and amphibians. It provides a highly sensitive and versatile hydrodynamic sense that is used in a wide range of behavior. Hydrodynamic stimuli of biological interest originate from both abiotic and biotic sources, and include water currents, turbulence and the water disturbances caused by other animals, such as prey, predators and conspecifics. However, the detection of biologically important stimuli often has to occur against a background of noise generated by water movement, or movement of the fish itself. As such, separating signal and noise is "of the essence" in understanding the behavior and physiology of mechanoreception. Here we discuss general issues of signal and noise in the lateral-line system and the behavioral and physiological strategies that are used by fish to enhance signal detection in a noisy environment. In order for signal and noise to be separated, they need to differ, and we will consider those differences under the headings of: frequency and temporal pattern; intensity discrimination; spatial separation; and mechanisms for the reduction of self-generated noise. We systematically cover the issues of signal and noise in lateral-line systems, but emphasize recent work on self-generated noise, and signal and noise issues related to prey search strategies and collision avoidance. [source] CHARMM: The biomolecular simulation programJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 10 2009B. R. Brooks Abstract CHARMM (Chemistry at HARvard Molecular Mechanics) is a highly versatile and widely used molecular simulation program. It has been developed over the last three decades with a primary focus on molecules of biological interest, including proteins, peptides, lipids, nucleic acids, carbohydrates, and small molecule ligands, as they occur in solution, crystals, and membrane environments. For the study of such systems, the program provides a large suite of computational tools that include numerous conformational and path sampling methods, free energy estimators, molecular minimization, dynamics, and analysis techniques, and model-building capabilities. The CHARMM program is applicable to problems involving a much broader class of many-particle systems. Calculations with CHARMM can be performed using a number of different energy functions and models, from mixed quantum mechanical-molecular mechanical force fields, to all-atom classical potential energy functions with explicit solvent and various boundary conditions, to implicit solvent and membrane models. The program has been ported to numerous platforms in both serial and parallel architectures. This article provides an overview of the program as it exists today with an emphasis on developments since the publication of the original CHARMM article in 1983. © 2009 Wiley Periodicals, Inc.J Comput Chem, 2009. [source] Facile, microwave-assisted parallel syntheses of N -substituted 1,4-dihydropyridines of biological interestJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 2 2009B. R. Prashantha Kumar A solventless parallel synthesis of some novel, N -substituted dihydropyridines by the application of microwaves is reported. The synthetic methodology adopted to synthesize the titled compounds and their antioxidant activity is described. J. Heterocyclic Chem., 46, 336 (2009). [source] Ion-pairing reversed-phase liquid chromatography/electrospray ionization mass spectrometric analysis of 76 underivatized amino acids of biological interest: a new tool for the diagnosis of inherited disorders of amino acid metabolismRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 12 2005Monique Piraud Seventy-six molecules of biological interest for the diagnosis of inherited disorders of amino acids (AA) metabolism have previously been demonstrated to be detectable in electrospray ionization tandem mass spectrometry (ESI-MS/MS) positive mode without derivatization. Reversed-phase liquid chromatography (RPLC) separation on different C18 columns using various perfluorinated carboxylic acids as ion-pairing agents has been found suitable for coupling with MS/MS, and for the separation of AA. A new procedure was optimized in order to replace the usual ion-exchange chromatographic, post-column ninhydrin derivatization, time-consuming routine method. This procedure allowed an adequate separation of all the molecules from other known interfering compounds, and a throughput of two samples per hour. Quantification limits for each molecule were found to be compatible with their measurement in plasma and urine. We validated the qualitative part of the method by analyzing plasma and urine samples from patients affected with several inherited disorders of AA metabolism. We validated the quantification of 16 AA using their stable isotopes as internal standard. The calibration curves were linear over the range 0,3,mM. The quantitative results obtained with the new method on 105 plasma and 99 urine samples were in good agreement with those obtained by the established routine method. Spiking experiments and precision results were also satisfactory. Copyright © 2005 John Wiley & Sons, Ltd. [source] New model for the hydroxyapatite,octacalcium phosphate interfaceACTA CRYSTALLOGRAPHICA SECTION B, Issue 2 2003M. E. Fernández Some experimental results have indicated that hydroxyapatite (HA) and octacalcium phosphate (OCP) can form an epitaxic interface. Subsequently the OCP,HA interface has become of great biological interest in the context of mineralized tissue formation. In this work a new OCP,HA interface model based on Brown's proposed configuration [Brown (1962), Nature, 197, 1048,1050] and using the minimum interface free-energy optimization is presented. This new model is formed by half a unit cell of HA and one unit cell of OCP, as in Brown's model, but in our case [110] of HA is `glued' with [010] of OCP. Therefore, the relationship found was: [000]HA parallel to [001]OCP and [110]HA parallel to [010]OCP. Self-consistent field methods were used for the analysis of Brown's model and ours. It is shown that the atoms in our model have similar environments as in the HA and OCP unit cells and that, as a result of the differences between HA and OCP unit-cell parameters, this interface presents misfit-dislocation-like features. High-resolution transmission electron microscopy (HREM) simulated images for the new interface model have been included and, when they are compared with the experimental ones, the similarity is quite good. [source] Graphene-like nets of hydrogen-bonded water molecules in the dihydrate of 2-[(2-ammonioethyl)amino]acetate and the structure of its anhydrous hydroiodide saltACTA CRYSTALLOGRAPHICA SECTION C, Issue 8 2010Tove Wiklund 2-[(2-Ammonioethyl)amino]acetate dihydrate, better known as N -(2-aminoethyl)glycine dihydrate, C4H10N2O2·2H2O, (I), crystallizes as a three-dimensional hydrogen-bonded network. Amino acid molecules form layers in the ac plane separated by layers of water molecules, which form a hydrogen-bonded two-dimensional net composed of fused six-membered rings having boat conformations. The crystal structure of the corresponding hydroiodide salt, namely 2-[(2-ammonioethyl)ammonio]acetate iodide, C4H11N2O2+·I,, (II), has also been determined. The structure of (II) does not accommodate any solvent water molecules, and displays stacks of amino acid molecules parallel to the a axis, with iodide ions located in channels, resulting in an overall three-dimensional hydrogen-bonded network structure. N -(2-Aminoethyl)glycine is a molecule of considerable biological interest, since its polyamide derivative forms the backbone in the DNA mimic peptide nucleic acid (PNA). [source] On testing biological data for the presence of a boundaryANNALS OF APPLIED BIOLOGY, Issue 2 2006A.E. Milne Abstract Under the boundary line model for a biological data set, where one variable is a biological response (e.g. crop yield) to an independent variable (e.g. available water content of the soil), we interpret the upper (or lower) boundary on a plot of the dependent variable (ordinate) against the independent variable (abscissa) as representing the maximum (or minimum) possible response for a given value of the independent variable. This concept has been widely used in soil science, agronomy and plant physiology; but it has been subject to criticism. In particular, no methods that are used to analyse the boundary line quantify the evidence that the envelope of the plot represents a boundary (in the sense of some limiting response to the independent variable) rather than simply being a fringe of extreme values of no intrinsic biological interest. In this article, we present a novel procedure that tests a data set for evidence of a boundary by considering its statistical properties in the region of the proposed boundary. The method is demonstrated using both simulated and real data sets. [source] Model-building strategies for low-resolution X-ray crystallographic dataACTA CRYSTALLOGRAPHICA SECTION D, Issue 2 2009Anjum M. Karmali The interpretation of low-resolution X-ray crystallographic data proves to be challenging even for the most experienced crystallographer. Ambiguity in the electron-density map makes main-chain tracing and side-chain assignment difficult. However, the number of structures solved at resolutions poorer than 3.5,Å is growing rapidly and the structures are often of high biological interest and importance. Here, the challenges faced in electron-density interpretation, the strategies that have been employed to overcome them and developments to automate the process are reviewed. The methods employed in model generation from electron microscopy, which share many of the same challenges in providing high-confidence models of macromolecular structures and assemblies, are also considered. [source] Plant cannabinoids: a neglected pharmacological treasure troveBRITISH JOURNAL OF PHARMACOLOGY, Issue 7 2005Raphael Mechoulam Most of the cannabinoids in Cannabis sativa L. have not been fully evaluated for their pharmacological activity. A publication in this issue presents evidence that a plant cannabinoid, ,9 -tetrahydrocannabivarin is a potent antagonist of anandamide, a major endogenous cannabinoid. It seems possible that many of the non-psychoactive constituents of this plant will be of biological interest. British Journal of Pharmacology (2005) 146, 913,915. doi:10.1038/sj.bjp.0706415 [source] Synthesis of Tricyclic Fused 3-Aminopyridines through Intramolecular CoI -Catalyzed [2+2+2] Cycloaddition between Ynamides, Nitriles, and AlkynesCHEMISTRY - A EUROPEAN JOURNAL, Issue 9 2009Pierre Garcia Abstract Three-ring circus: An expedient route to tricyclic fused 2-trimethylsilyl-3-aminopyridines exhibiting unprecedented skeletons is described. The key step is a very efficient cobalt-catalyzed [2+2+2] cycloaddition of a polyunsaturated compound displaying an ynamide, an alkyne, and a nitrile functionality (see picture). The first [2+2+2] cocyclizations between ynamides, nitriles, and alkynes are reported. They open a new access to unprecedented nitrogen-containing heterocycles of type 2-trimethylsilyl-3-aminopyridines. Such frameworks, which can be found in various compounds of biological interest, are very difficult to prepare by conventional methods. However, using [CpCo(C2H4)2] (Cp=cyclopentadienyl) as catalyst, the intramolecular cyclizations could be achieved in up to 100,% yield. The presence of the trimethylsilyl group allowed a rare type of Hiyama cross-coupling: one of the silylated pyridines could be coupled with p -iodoanisole to give a new type of biaryl system. [source] | |||||||||||||||||||||||||