Synthesis,spectroscopic and antibacterial investigations of new hydroxy ethers and heterocyclic coumarin derivatives

The reactions between oligoethylene glycol diglycidyl ethers 2a‐c with both 7‐hydroxy‐4‐methyl‐2H‐chromen‐2‐one and 4‐hydroxy‐2H‐chromen‐2‐one lead to new hydroxy ethers 3 and 4 containing coumarin moieties in good yield. The synthesis of 3‐(3‐(dimethylamino)acryloyl)‐4‐hydroxy‐2H‐chromen‐2‐one 5 and new heterocyclic compounds 4‐hydroxy‐3‐(1H‐pyrazol‐3‐yl)‐2H‐chromen‐2‐one 6a , 4‐hydroxy‐3‐(1‐phenylpyrazol‐3‐yl)‐2H‐chromen‐2‐one 6b and 4‐hydroxy‐3‐(isoxazol‐3‐yl)‐2H‐chromen‐2‐one 6c is also described. All compounds were characterized by ¹H NMR, ¹³C{¹H} NMR, 2D‐¹H‐¹³C HMBC, 2D‐¹H NOESY NMR, IR, and MS spectroscopy. Additionally, the antibacterial activity of the new products containing coumarin moiety was evaluated. This activity is clearly dependent on the chemical structure of compounds.     

Immunoaffinity purification and characterization of mitochondrial membrane-bound D-3-hydroxybutyrate dehydrogenase from <Emphasis Type="Italic">Jaculus orientalis</Emphasis>

Background  

The interconversion of two important energy metabolites, 3-hydroxybutyrate and acetoacetate (the major ketone bodies), is catalyzed by D-3-hydroxybutyrate dehydrogenase (BDH¹: EC 1.1.1.30), a NAD⁺-dependent enzyme. The eukaryotic enzyme is bound to the mitochondrial inner membrane and harbors a unique lecithin-dependent activity. Here, we report an advanced purification method of the mammalian BDH applied to the liver enzyme from jerboa (Jaculus orientalis), a hibernating rodent adapted to extreme diet and environmental conditions.     

Dissipative structures in left-handed material cavity optics

We study the spatiotemporal dynamics of spatially extended nonlinear cavities containing a left-handed material. Such materials, which have a negative index of refraction, have been experimentally demonstrated recently, and allow for novel electromagnetic behavior. We show that the insertion of a left-handed material in an optical resonator allows for controlling the value and the sign of the diffraction coefficient in dispersive Kerr resonators and degenerate optical parametric oscillators. We give an overview of our analytical and numerical studies on the stability and formation of dissipative structures in systems with negative diffraction.     

Introduction: dissipative localized structures in extended systems

Localized structures belong to the class of dissipative structures found far from equilibrium. Contributions from the most representative groups working on a various fields of natural science such as biology, chemistry, plant ecology, mathematics, optics, and laser physics are presented. The aim of this issue is to gather specialists from these fields towards a cross-fertilization among these active areas of research and thereby to present an overview of the state of art in the formation and the characterization of dissipative localized structures. Nonlinear optics and laser physics have an important part in this issue because of potential applications in information technology. In particular, localized structures could be used as "bits" for parallel information storage and processing.     

Environmental impact assessment of post illegal mining activities in Chini Lake with regards to natural radionuclides and heavy metals in water and sediment

Journal of Radioanalytical and Nuclear Chemistry - Comprehensive radiological survey and evaluation of heavy metal contamination were conducted in Chini Lake, which has been awarded a pristine...     

Detection and Prevention of Ocular Phototoxicity of Ciprofloxacin and Other Fluoroquinolone Antibiotics†

Fluoroquinolone (FLQ) drugs are a potent family of antibiotics used to treat infections including ocular infections. To determine if these antibiotics may be phototoxic to the eye, we exposed human lens epithelial cells to 0.125–1 mm FLQs (ciprofloxacin [Cipro], lomefloxacin [Lome], norfloxacin [Nor] and ofloxacin [Ofl]), the precursor quinolone nalidixic acid (Nalid) and UVA radiation (2.5 J cm⁻²). Based on fluorescence confocal microscopy, FLQs are diffused throughout the cytoplasm and preferentially located in the lysosomes of lens epithelial cells. Neither FLQ exposure alone nor UVA exposure alone reduced cell viability. However, with exposure to UVA radiation the FLQs studied (Cipro, Nor, Lome and Ofl) induced a phototoxic reaction that included necrosis, apoptosis, loss of cell viability as measured by MTS, and membrane damage as determined by the lactate dehydrogenase assay. Both Nalid and all FLQs studied (Cipro, Nor, Lome and Ofl) photopolymerized the lens protein α-crystallin. Phototoxic damage to lens epithelial cells and/or α-crystallin will lead to a loss of transparency of the human lens. However, if precautions are taken to filter all UV radiation from the eye while taking these antibiotics, eye damage may be prevented.     

Electronic structure and coordination chemistry of phenanthridine ligand in first‐row transition metal complexes: A DFT study

The geometric parameters, electronic structures, and haptotropic migration of a series of hypothetical compounds of general formula CpM(C₁₃H₉N) and (CO)₃M(C₁₃H₉N) (M = fist row transition metal, Cp = C₅H₅, and C₁₃H₉N = phenanthridine ligand) are investigated by means of the density functional theory. The phenanthridine ligand can bind to the metal through η¹ to η⁶ coordination mode, in agreement with the electron count and the nature of the metal, showing its capability to adapt itself to the electronic demand of the metal as well as to the polycyclic aromatic hydrocarbons. In the investigated species, the most favored closed‐shell count is 18‐electron except for the Ti and V models which are deficient open‐shell 16‐electron configuration. This study has shown the difference in coordination ability of this heteropolycyclic ligand: the coordination of the central C₅N ring is less favored than the terminal C₆ rings, in agreement with the π‐electron density localization. Most of the investigated complexes are expected to exhibit a rich fluxional behavior. This flexibility favors the possibility for the existence of several isomers as well as their interconversion through haptotropic shifts. © 2012 Wiley Periodicals, Inc.     

Convergence Rates to Equilibrium for Neutron Chain Fissions

We study a class of nonlinear equations arising in the stochastic theory of neutron transport. After proving existence and uniqueness of the solution, we consider the large-time behaviour of the solution and give explicit rates of convergence of the solution towards the asymptotic state.