The interaction of [Co(H₂O)₄(p-NO₂C₆H₄COO)₂]. 2H₂O with sheep genomicDNA has been investigated by spectroscopic studies and electrophoresis measurements.The interaction between cobalt(II) p-nitrobenzoate and DNA has been followed by gelelectrophoresis while the concentration of the complex was increased from 0 to 14 mM.The spectroscopic study and electrophoretic experiments support the fact that the complexbinds to DNA by intercalation via p-nitrobenzoate into the base pairs of DNA. Themobility of the bands decreased as the concentration of complex was increased, indicatingthat there was increase in interaction between the metal ion and DNA. Full article

The Electronegativity Equalization Method (EEM) is a fast approach for chargecalculation. A challenging part of the EEM is the parameterization, which is performedusing ab initio charges obtained for a set of molecules. The goal of our work was to performthe EEM parameterization for selected sets of organic, organohalogen and organometalmolecules. We have performed the most robust parameterization published so far. The EEMparameterization was based on 12 training sets selected from a database of predicted 3Dstructures (NCI DIS) and from a database of crystallographic structures (CSD). Each setcontained from 2000 to 6000 molecules. We have shown that the number of molecules inthe training set is very important for quality of the parameters. We have improved EEMparameters (STO-3G MPA charges) for elements that were already parameterized,specifically: C, O, N, H, S, F and Cl. The new parameters provide more accurate chargesthan those published previously. We have also developed new parameters for elements thatwere not parameterized yet, specifically for Br, I, Fe and Zn. We have also performedcrossover validation of all obtained parameters using all training sets that included relevantelements and confirmed that calculated parameters provide accurate charges. Full article

The discovery of communication systems regulating bacterial virulence hasafforded a novel opportunity to control infectious bacteria without interfering withgrowth. In this paper we describe the effect of subinhibitory concentrations of phenyl-lactic acid (PLA) on the pathogenicity of Pseudomonas aeruginosa in mice. The animalswere inoculated by oral (p.o.), intranasal (i.n.), intravenous (i.v.) and intraperitoneal (i.p.)routes with P. aeruginoasa wild and PLA-treated cultures. The mice were followed upduring 16 days after infection and the body weight, mortality and morbidity rate weremeasured every day. The microbial charge was studied by viable cell counts in lungs,spleen, intestinal mucosa and blood. The mice batches infected with wild P. aeruginosabacterial cultures exhibited high mortality rates (100 % after i.v. and i.p. route) and veryhigh cell counts in blood, lungs, intestine and spleen. In contrast, the animal batchesinfected with PLA treated bacterial cultures exhibited good survival rates (0 % mortality) and the viable cell counts in the internal organs revealed with one exception the complete abolition of the invasive capacity of the tested strains. In this study, using a mouse infection model we show that D-3-phenyllactic acid (PLA) can act as a potent antagonist of Pseudomonas (P.) aeruginosa pathogenicity, without interfering with the bacterial growth, as demonstrated by the improvement of the survival rates as well as the clearance of bacterial strains from the body. Full article

The liquid-liquid equilibrium for the ternary system formed by n-octane andaromatic (alkylbenzenes) and heteroaromatic compounds (nitrogen and sulfur containingheterocyles) and 1-alkyl-3-methylimidazolium ionic liquids (ILs) associated with variousanions has been investigated. The selectivity on the extraction of a specific aromaticcompound is influenced by anion volume, hydrogen bond strength between the anion andthe imidazolium cation and the length of the 1-methyl-3-alkylimidazolium alkyl side chain.The interaction of alkylbenzenes and sulfur heterocyles with the IL is preferentially throughCH-π hydrogen bonds and the quantity of these aromatics in the IL phase decreases withthe increase of the steric hindrance imposed by the substituents on the aromatic nucleus. Inthe case of nitrogen heterocycles the interaction occurs preferentially throughN(heteroaromatic)-H(imidazolium) hydrogen bonds and the extraction process is largelycontrolled by the nitrogen heterocycle pKa. Competitive extraction experiments suggestthat benzene, pyridine and dibenzothiophene do not compete for the same hydrogen bondsites of the IL. Full article

The effect of medium doses of γ-irradiation (1-10 kGy) on total phenolic andtannin contents, lipid peroxidation, protein oxidation intensity and soluble protein contentof soybean seeds, (genotype Ana), was investigated. Screening for antioxidant ability wasperformed using FRAP and DPPH methods. Total phenolic and tannin contents and DPPHscavenger activity were increased, while protein oxidation intensity was decreased byapplied doses of γ-irradiation. Gamma irradiation provoked insignificant changes in lipidperoxidation and soluble protein content, while protein oxidation intensity wassignificantly decreased when dose of 10 kGy was applied. Presented results implicated thatincreased antioxidant capacity and protein stability of soybean seeds were increased afterapplication of γ-irradiation. Full article

The ring hydrogenation of benzoic acid to cyclohexanecarboxylic acid overcharcoal-supported transition metal catalysts in supercritical CO₂ medium has been studiedin the present work. The cyclohexanecarboxylic acid can be produced efficiently insupercritical CO₂ at the low reaction temperature of 323 K. The presence of CO₂ increasesthe reaction rate and several parameters have been discussed. Full article

Nuclei of hemlock (Tsuga canadensis and Tsuga canadensis var. nana) wereinvestigated for the presence of flavanols. Histochemical staining with p-dimethylaminocinnamaldehyde proved to be a highly valuable method yielding a brightblue flavanol coloration for nuclei. There was a significant variation in flavanol deposition(1) among nuclei, (2) at the subnuclear level and also (3) along the chromosomes duringmitosis. The presence of flavanols in nucleoli could not be established probably becausethey were too small, measuring less than 1 μm in diameter. In contrast to Tsuga, the cellsand nuclei of rootlets from rye (Secale cereale) were totally devoid of natural flavanols.However, externally added flavanols, catechin and epicatechin, were bound to the ryenuclei, while the rather large nucleoli failed to associate with the flavanols. The strong sinkactivity of nucleoplasm and chromosomes for flavanols in Tsuga and Secale indicates aprocess which is apparently widespread even in distantly related plant species. Variationsin chromatin-associated flavanols could to some extent be induced byacetylation/deacetylation of histones, as confirmed in the present study by means of UV-VIS spectroscopic titrations of histone sulphate and chemically acetylated histone sulphate. Full article

It has been shown by chromatography that aglycone, glucoside, acetylglucosideand malonylglucoside isoflavone extracts prepared from soybean cake showed betterantioxidant activities than isoflavone standards. Consequently, the aim of this study was toevaluate the protective effects of these isoflavone extracts against ultraviolet B (UVB)-induced keratinocyte damage. Our results demonstrated that these soybean cake isoflavoneextracts could inhibit UVB-induced keratinocyte death. Moreover, they could inhibit UVB-induced intracellular release of hydrogen peroxide (H₂O₂) Furthermore, these isoflavoneextracts differentially inhibited UVB-induced MAPK phosphorylation. The ERK1/2 andp38 phosphorylation was not inhibited by all tested isoflavone extracts, whereas JNKphosphorylation was inhibited by group I to group III isoflavone extracts. Since theseisoflavone extracts are relative stable and easily obtained than the isoflavone standards, wesuggest that soybean cake may be a useful potential source for developing effective skincare agents in against photoaging. Full article

In this study, sulfated low molecular-weight Tremella fuciformis polysaccharides(SLTP) with different sulfate contents were synthesized and their antioxidant activities,including superoxide anion radical, 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical andhydroxyl radical scavenging activities were investigated. The results indicated that,compared to natural Tremella fuciformis polysaccharide (TP) and low molecular weightTremella fuciformis polysaccharide (LTP), sulfated LTP (SLTP) exhibited strongerscavenging activity towards superoxide anion, DPPH and hydroxyl radicals. In all the casesthe effect was found to be dose dependent. The scavenging activity of SLTP was found tobe in parallel with the degree of sulfation of SLTP. Full article

A process to produce fibers from Poly(m-phenyleneisophthalamide)(PMIA)solution in an ionic liquid via wet-spinning technology are described. The spinning processwas investigated on a small laboratory scale. Ionic liquid spinning solutions were firstprepared for PMIA fibers, followed by wet spinning. In the course of this research, thephysical properties of the PMIA fibers were estimated. We studied the dependence of themechanical properties of the obtained PMIA fibers on the composition of the coagulationbath, and on the choice of solvent in spinning solution. The morphology of the fibers fromionic liquid and traditional DMAc solvents via wet-spinning process were observed byscanning electrical microscopy(SEM). The differences of morphologies and properties ofthe PMIA fibers obtained from two different solvents are discussed. Full article

A thermochemical rather simple experimental technique is applied to determinethe enthalpy of formation of Diperoxide of ciclohexanone. The study is complemented withsuitable theoretical calculations at the semiempirical and ab initio levels. A particularsatisfactory agreement between both ways is found for the ab initio calculation at the 6-311G basis This set level. Some possible extensions of the present procedure are pointedout. Full article

Fluorinated nucleoside analogues are known as antitumor, antiviral andchemotherapeutic agents, although the antioxidant activity of this kind of molecules is notyet investigated. In this study we have tested the antioxidant activity of a series of modifiedpyrano-nucleoside analogues using three in vitro assays. Firstly, the antioxidant capacity ofthe products was assessed using the DPPH assay and secondly, in order to examine theability of the products to protect DNA from the activity of reactive oxygen species (ROS),a peroxyl radical (ROO•) and a hydroxyl radical (OH•) induced DNA strand scission assaywere used. None of the molecules showed the ability to scavenge DPPH radical andprevent OH• induced DNA strand breakage. Although, most of the tested nucleosideanalogues, had the ability to prevent ROO• induced DNA damage. Full article

Carbon nanotubes (CNTs) can be effectively dispersed and functionalized bywrapping with long single-stranded DNA (ssDNA) synthesized by asymmetric PCR. ThessDNA-CNTs attached on surface of glass carbon electrode made it possible forelectrochemical analysis and sensing, which was demonstrated by reduction of H₂O₂ onhemoglobin/ssDNA-CNTs modified electrodes. This research showed the potentialapplication of DNA-functionalised CNTs in construction of future electrochemicalbiosensors. Full article

Phosphodiesterase-4 (PDE4) plays an important role in treatment of asthma andchronic obstructive pulmonary disease. Thirty-one analogs displaying variable inhibition ofPDE4 were selected to develop models for establishing three-dimensional quantitativestructure-activity relationships (3D-QSAR). Comparative molecular field analysis(CoMFA) was conducted on the group of analogs to determine the structural requirementsfor potency in inhibiting PDE4. The resulting model exhibited good q² and r² values up to0.741 and 0.954 for CoMFA. The contributions from the steric and electrostatic fields were0.915 and 0.085 respectively. The 3D-QSAR model should be very useful for design ofnovel PDE 4 inhibitors. Full article

A bromide–modified silver electrode is reported, in the present study, to catalyzethe redox reactions of metalloproteins. This study describes that the bromide ions showvery good redox behavior with silver electrode. The cathodic and anodic peak potentialswere related to the concentration of bromide ions involved in making bromide-modifiedsilver electrode. The electrode reaction in the bromine solution was a diffusion-controlledprocess. Positive potential shift of the bromide ions was seen when different proteins wereadded to the solution using a silver electrode. New cathodic and anodic peaks wereobserved at different potential ranges for myoglobin, cytochrome c and catalase. A linearlyincreasing cathodic peak current of bromide ions was seen when the concentration ofsuperoxide dismutase was increased in the test solution. However, no change for albuminwas observed when its concentration was increased in the test solution. Present data provesour methodology as an easy-to-use analysis for comparing the redox potentials of differentmetalloproteins and differentiating the metallo- from non-metalloproteins. In this study, weintroduced an interesting method for bio-electrochemical analyses. Full article