224 research outputs found
New mono- and polynuclear copper(II) complexes: Structural characterization, quantum chemical calculations and antioxidant superoxide dismutase studies
Two copper(II) complexes have been synthesized and characterized using elemental and spectral analysis. The molecular structures of both complexes have been confirmed by single crystal X-ray analysis. The stability of the metal centre was examined using cyclic and differential pulse voltammetry in DMSO solution. X-band electron paramagnetic spectra were recorded both in solid and frozen solution to confirm the d9 configuration. Frozen solution spectra of complexes have the trend in the spin Hamiltonian parameters and cm-1 revealing a ground state with tetragonal symmetry for copper(II) ion. Density functional calculations have been performed and results are found to agree with the experimental results. Antibacterial activities of complexes were screened by taking gram-positive and gram-negative bacteria. Further, in vitro antioxidant (superoxide dismutase) properties of 1 and 2 showed considerable activity compared to other SOD mimics
New mono- and polynuclear copper(II) complexes: Structural characterization, quantum chemical calculations and antioxidant superoxide dismutase studies
506-518Two copper(II) complexes have been synthesized and characterized using elemental and spectral analysis. The molecular structures of both complexes have been confirmed by single crystal X-ray analysis. The stability of the metal centre was examined using cyclic and differential pulse voltammetry in DMSO solution. X-band electron paramagnetic spectra were recorded both in solid and frozen solution to confirm the d9 configuration. Frozen solution spectra of complexes have the trend in the spin Hamiltonian parameters gǁ > g > 2.0023 and Aǁ 156 x 10-4 cm-1 revealing a dx2-y2 ground state with tetragonal symmetry for copper(II) ion. Density functional calculations have been performed and results are found to agree with the experimental results. Antibacterial activities of complexes were screened by taking gram-positive and gram-negative bacteria. Further, in vitro antioxidant (superoxide dismutase) properties of 1 and 2 showed considerable activity compared to other SOD mimics
3-[2-(6-Bromo-2-phenyl-3H-imidazo[4,5-b]pyridin-3-yl)ethyl]-1,3-oxazolidin-2-one
In the title molecule, C17H15BrN4O2, the fused-ring system is essentially planar, the largest deviation from the mean plane being 0.015 (2) Å, and forms dihedral angles of 37.8 (2) and 35.5 (2)° with the phenyl and oxazolidine rings, respectively. The conformation adopted by the molecule is stabilized by an intramolecular π⋯π interaction [centroid–centroid distance = 3.855(2) Å] between oxazolidine and phenyl rings. The crystal packing features intermolecular C—H⋯N and C—H⋯O interactions
Bis[methyl 3-(propylamino)but-2-enoato]zinc
The title compound, [Zn(C8H14NO2)2], represents a zinc complex with the Zn2+ cation coordinated by two O and two N atoms in a distorted tetrahedral geometry
1,3-Bis(prop-2-ynyl)-1H-1,3-benzimidazol-2(3H)-one
In the title compound, C13H10N2O, the fused-ring system is essentially planar, the largest deviation from the mean plane being 0.015 (1) Å. The two propynyl groups are nearly perpendicular to the benzimidazole plane, making dihedral angles of 85 (3) and 80 (2) °, and point in opposite directions. There are two short intermolecular C—H⋯O contacts to the carbonyl O atom, one involving the acetylenic H atom and the other a H atom of the methylene group
Local and global modes of drug action in biochemical networks
It becomes increasingly accepted that a shift is needed from the traditional target-based approach of drug development to an integrated perspective of drug action in biochemical systems. We here present an integrative analysis of the interactions between drugs and metabolism based on the concept of drug scope. The drug scope represents the set of metabolic compounds and reactions that are potentially affected by a drug. We constructed and analyzed the scopes of all US approved drugs having metabolic targets. Our analysis shows that the distribution of drug scopes is highly uneven, and that drugs can be classified into several categories based on their scopes. Some of them have small scopes corresponding to localized action, while others have large scopes corresponding to potential large-scale systemic action. These groups are well conserved throughout different topologies of the underlying metabolic network. They can furthermore be associated to specific drug therapeutic properties
The Imprint of Galaxy Formation on X-ray Clusters
It is widely believed that structure in the Universe evolves hierarchically,
as primordial density fluctuations, amplified by gravity, collapse and merge to
form progressively larger systems. The structure and evolution of X-ray
clusters, however, seems at odds with this hierarchical scenario for structure
formation. Poor clusters and groups, as well as most distant clusters detected
to date, are substantially fainter than expected from the tight relations
between luminosity, temperature and redshift predicted by these models. Here we
show that these discrepancies arise because, near the centre, the entropy of
the hot, diffuse intracluster medium (ICM) is higher tha possible if the ICM
is heated at modest redshift (z \ltsim 2) but prior to cluster collapse,
indicating that the formation of galaxies precedes that of clusters and that
most clusters have been assembled very recently.Comment: 5 pages, plus 2 postscript figures (one in colour), accepted for
publication in Natur
Complex aetiology of an apparently Mendelian form of Mental Retardation
<p>Abstract</p> <p>Background</p> <p>Mental Retardation is a common heterogeneous neurodevelopment condition, which causes are still largely elusive. It has been suggested that half of the phenotypic variation of intelligence is explained by genetic variation. And genetic or inherited factors indeed account for most of the cases of mental retardation with an identifiable cause. However, only a few autosomal genes have been mapped and identified to date. In this report, the genetic causes for an apparently recessive form of mental retardation, in a large nordern swedish pedigree, are investigated.</p> <p>Methods</p> <p>After extensive evaluation of the patients, which ruled out recognizable patterns of malformation and excluded known causes of MR, a comprehensive genome-wide linkage analysis, with 500 microsatellite markers, was performed in 24 members of this family. Additionally, a genome-wide copy number analysis, using an affimetrix 250 K SNP chip, was performed in this pedigree.</p> <p>Results</p> <p>No significant LOD score was found with either parametric and non-parametric linkage analysis. The highest scores are located at chromosomes 13, 15 and 17. Genome-wide copy number analysis identified no clear cause for the disorder; but rather, several variants were present in the family members, irrespective of their affected status.</p> <p>Conclusion</p> <p>These results suggest that mental retardation in this family, unlikely what was expected, has a heterogeneous aetiology; and that several lower effect genes variants might be involved. To demonstrate such effects, our family may be too small. This study also indicates that the ascertainment of the cause of MR may be challenging, and that a complex aetiology may be present even within a pedigree, constituting an additional obstacle for genetic counselling. Variants in genes involved in molecular mechanisms of cellular plasticity, in genes involved in the development of underlying neural architectures, and in genes involved in neurodevelopment and in the ongoing function of terminally differentiated neurons may underlie the phenotypic variation of intelligence and explain instances of intellectual impairment.</p
Carbonate-Templated Self-Assembly of an Alkylthiolate-Bridged Cadmium Macrocycle
In the presence of Cd(ClO4)2 and a base, a new mixed N,S-donor alkylthiolate ligand supported both carbonate formation from atmospheric CO2 and the self-assembly of a novel bicapped puckered (CdS)6 molecular wheel. The remarkable stability of the complex was demonstrated by slow intermolecular ligand exchange on the 2J(HH) and J(111/113Cd1H) time scales at elevated temperature. Both CO2 and the base were required to convert amorphous “CdLClO4” precipitated in the absence of air to the carbonate complex. The complex shares structural features with the ζ-carbonic anhydrase class associating cadmium(II) with the biogeochemical cycling of carbon and is the first structurally characterized carbonate complex of any metal involving an alkylthiolate ligand
Observation of focusing of 400 GeV/c proton beam with the help of bent crystals
The results of observation and studies of focusing of 400 GeV/ c proton beam with the help of bent single crystals are presented. Two silicon crystals have been used in the measurements. The focal length of the first and second crystals is found to be 1.48 m and 0.68 m, respectively. The mean square size of the horizontal profile in the focus was 3.1 and 4.3 times as small as at the exit of the crystals
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