Serum from Calorie-Restricted Rats Activates Vascular Cell eNOS through Enhanced Insulin Signaling Mediated by Adiponectin

eNOS activation resulting in mitochondrial biogenesis is believed to play a central role in life span extension promoted by calorie restriction (CR). We investigated the mechanism of this activation by treating vascular cells with serum from CR rats and found increased Akt and eNOS phosphorylation, in addition to enhanced nitrite release. Inhibiting Akt phosphorylation or immunoprecipitating adiponectin (found in high quantities in CR serum) completely prevented the increment in nitrite release and eNOS activation. Overall, we demonstrate that adiponectin in the serum from CR animals increases NO center dot signaling by activating the insulin pathway. These results suggest this hormone may be a determinant regulator of the beneficial effects of CR.

Electrical conductivity of silicate glasses with tetravalent cations substituting Si

The effects of substituting Si by M4+ cations in soda-lime silica glasses were analyzed by impedance spectroscopy in the frequency range of 1 Hz-1 MHz. The glass composition was (mol%) 22Na(2)O center dot 8CaO center dot 65SiO(2)center dot 5MO(2), M = Si, Ti, Ge, Zr, Sn, and Ce. Although the Na+ concentration in the glasses is constant, the Zr-containing glass exhibits the highest dc conductivity and the lowest activation energy, while the Ce-containing glass exhibits the lowest conductivity. The activation energies obtained experimentally agree with those obtained by a theoretical equation proposed by Anderson and Stuart. The differences in electrical conductivity presented by the several M-containing glasses are attributed to the effect that the M4+ ion has on the mobility of the diffusing Na+ ion. (C) 2012 Elsevier B.V. All rights reserved.

NADPH Phagocyte Oxidase Knockout Mice Control Trypanosoma cruzi Proliferation, but Develop Circulatory Collapse and Succumb to Infection

(NO)-N-center dot is considered to be a key macrophage-derived cytotoxic effector during Trypanosoma cruzi infection. On the other hand, the microbicidal properties of reactive oxygen species (ROS) are well recognized, but little importance has been attributed to them during in vivo infection with T. cruzi. In order to investigate the role of ROS in T. cruzi infection, mice deficient in NADPH phagocyte oxidase (gp91(phox-/-) or phox KO) were infected with Y strain of T. cruzi and the course of infection was followed. phox KO mice had similar parasitemia, similar tissue parasitism and similar levels of IFN-gamma and TNF in serum and spleen cell culture supernatants, when compared to wild-type controls. However, all phox KO mice succumbed to infection between day 15 and 21 after inoculation with the parasite, while 60% of wild-type mice were alive 50 days after infection. Further investigation demonstrated increased serum levels of nitrite and nitrate (NOx) at day 15 of infection in phox KO animals, associated with a drop in blood pressure. Treatment with a NOS2 inhibitor corrected the blood pressure, implicating NOS2 in this phenomenon. We postulate that superoxide reacts with (NO)-N-center dot in vivo, preventing blood pressure drops in wild type mice. Hence, whilst superoxide from phagocytes did not play a critical role in parasite control in the phox KO animals, its production would have an important protective effect against blood pressure decline during infection with T. cruzi.

Witzkeite: A new rare nitrate-sulphate mineral from a guano deposit at Punta de Lobos, Chile

Witzkeite, ideally Na4K4Ca(NO3)(2)(SO4)(4)center dot 2H(2)O, is a new mineral found in the oxidation zone of the guano mining field at Punta de Lobos, Tarapaca region, Chile. It occurs as colorless, tabular crystals up to 140 mu m in length, associated with dittmanite and nitratine. Witzkeite is colorless and transparent, with a white streak and a vitreous luster. It is brittle, with Molts hardness 2 and distinct cleavage on {001}. Measured density is 2.40(2) g/cm(3), calculated density is 2.403 g/cm(3). Witzkeite is biaxial (-) with refractive indexes alpha = 1.470(5), beta = 1.495(5), gamma = 1.510(5), measured 2V = 50-70 degrees. The empirical composition is (electron microprobe, mean of five analyses, H2O, CO2, and N2O5 by gas chromatography; wt%): Na2O 12.83, K2O 22.64, CaO 7.57, FeO 0.44, SO3 39.96, N2O5 12.7, H2O 4.5, total 100.64; CO2 was not detected. The chemical formula, calculated based on 24 O, is: Na3.40K3.95Ca1.11Fe0.05(NO3)(1.93)(SO4)(4.10)(H4.10O1.81). Witzkeite is monoclinic, space group C2/c, with unit-cell parameters: a = 24.902(2), b = 5.3323(4), c = 17.246(1) angstrom, beta = 94.281(7)degrees, V = 2283.6(3) angstrom(3) (Z = 4). The crystal structure was solved using single-crystal X-ray diffraction data and refined to R-1(F) = 0.043. Witzkeite belongs to a new structure type and is noteworthy for the very rare simultaneous presence of sulfate and nitrate groups. The eight strongest X-ray powder-diffraction lines [d in angstrom (I in %) (h k l)] are: 12.38 (100) (2 0 0), 4.13 (19) (6 0 0), 3.10 (24) (8 0 0), 2.99 (7) ((8) over bar 02), 2.85 (6) (8 02), 2.69 (9) ((7) over bar 1 3), 2.48 (12) (10 0 0), and 2.07 (54) (12 0 0). The IR spectrum of witzkeite was collected in the range 390-4000 cm(-1). The spectrum shows the typical bands of SO42- ions (1192, 1154, 1116, 1101, 1084, 993, 634, and 617 cm(-1)) and of NO3- ions (1385, 1354, 830, 716, and 2775 cm(-1)). Moreover, a complex pattern of bands related to H2O is visible (bands at 3565, 3419, 3260, 2405, 2110, 1638, and 499 cm(-1)). The IR spectrum is discussed in detail.

Synthesis and characterization of CeO2-graphene composite

The synthesis and characterization of graphite oxide (GO), graphene (GS), and the composites: GS-CeO2 and GO-CeO2 are reported. This synthesis was carried out by mixing aqueous solutions of CeCl3 center dot 7H(2)O and GO, which yields the oxidized composite GO-CeO2. GO-CeO2 was hydrothermally reduced with ethylene glycol, at 120 A degrees C, yielding the reduced composite GS-CeO2. GO, GS ,and the composites with CeO2 were characterized by CHN, TG/DTG, BET, XRD, SEM microscopy, FTIR, and Raman spectroscopy. The estimation of crystallite size of CeO2 anchored on GO and on GS by Raman, XRD, and SEM agreed very well showing diameters about 5 nm. The role of particles of CeO2 coating carbon sheets of GO and GS was discussed.

Antioxidant Activity of Brazilian Vegetables and Its Relation with Phenolic Composition

Vegetables are widely consumed in Brazil and exported to several countries. This study was performed to evaluate the phenolic content and antioxidant activity of vegetables commonly consumed in Brazil using five different methods, namely DPPH and ABTS free radical, beta-carotene bleaching, reduction of Fe3+ (FRAP), oxidative stability in Rancimat, and the chemical composition using gas chromatography-mass spectrometry (GC-MS). The content of phenolic compounds ranged from 1.2 mg GA/g (carrot) to 16.9 mg GA/g (lettuce). Vegetables presenting the highest antioxidant activity were lettuce (77.2 mu mol Trolox/g DPPH center dot; 447.1 mu mol F2+/g FRAP), turmeric (118.6 mu mol Trolox/g ABTS(center dot+); 92.8% beta-carotene), watercress and broccoli (protective factor 1.29-Rancimat method). Artichoke, spinach, broccoli, and asparagus also showed considerable antioxidant activity. The most frequent phenolic compounds identified by GC-MS were ferulic, caffeic, p-coumaric, 2-dihydroxybenzoic, 2,5-dihydroxybenzoic acids, and quercetin. We observed antioxidant activity in several vegetables and our results point out their importance in the diet.

Synthesis, biological evaluation and molecular docking studies of 3-(triazolyl)coumarin derivatives: Effect on inducible nitric oxide synthase

A series of 3-(triazolyl)-coumarins were synthesized and tested as anti-inflammatory agents. It was possible to infer that these compounds do not alter the interaction of LPS with TLR-4 or TLR-2, as the intracellular pathways involved in the TNF-alpha secretion and COX-2 activity were not affected. Nevertheless, the compounds inhibited iNOS-derived NO production, without affecting the eNOS activity. The outcome of the docking studies showed that it pi center dot center dot center dot pi interactions with the heme group are important for the iNOS inhibition, thus making compound 3c a promising lead. Moreover, the efficacy of this compound was visualized by the reduced number of neutrophils in the LPS-inflamed subcutaneous tissue. Together, biological and docking data show that triazolyl-substituted coumarins, that can act on iNOS, are a good scaffold to be explored. (C) 2012 Elsevier Masson SAS. All rights reserved.

Identification of a crab gill FXYD2 protein and regulation of crab microsomal Na, K-ATPase activity by mammalian FXYD2 peptide

This investigation discloses the recognition of an FXYD2 protein in a microsomal Na,K-ATPase preparation from the posterior gills of the blue crab, Callinectes danae, by a mammalian (rabbit) FXYD2 peptide specific antibody (gamma C-33) and MALDI-TOF-TOF mass spectrometry techniques. This is the first demonstration of an invertebrate FXYD2 protein. The addition of exogenous pig FXYD2 peptide to the crab gill microsomal fraction stimulated Na,K-ATPase activity in a dose-dependent manner. Exogenous pig FXYD2 also considerably increased enzyme affinity for K+, ATP and N-4(+)center dot K-0.5 for Na+ was unaffected. Exogenous pig FXYD2 increased the V-max for stimulation of gill Na,K-ATPase activity by Na+, K+ and ATP, by 30% to 40%. The crab gill FXYD2 is phosphorylated by PKA, suggesting a regulatory function similar to that known for the mammalian enzyme. The PKA-phosphorylated pig FXYD2 peptide stimulated the crab gill Na,K-ATPase activity by 80%, about 2-fold greater than did the non-phosphorylated peptide. Stimulation by the PKC-phosphorylated pig FXYD2 peptide was minimal. These findings confirm the presence of an FXYD2 peptide in the crab gill Na, K-ATPase and demonstrate that this peptide plays an important role in regulating enzyme activity. (C) 2012 Elsevier B.V. All rights reserved.

Dinuclear copper(II) complexes with valsartan. Synthesis, characterization and cytotoxicity

Two novel dinuclear complexes involving the antihypertensive drug valsartan and copper(II) ion have been prepared in water and DMSO. The complex compositions were determined as: [Cu(vals)(H(2)O)(3)](2)center dot 6H(2)O and [Cu(vals)(H(2)O)(2)DMSO](2)center dot 2H(2)O. They were thoroughly characterized by elemental and thermal analysis, spectrophotometric titrations and UV-visible, diffuse reflectance, FTIR, Raman and EPR spectroscopies. No effect of the ligand on two tested osteoblastic cell lines in culture (one normal MOT3E1 and one tumoral UMR106) was observed in concentrations up to 100 mu M. Higher concentrations of Valsartan are required to induce cytotoxicity in both cell lines. The antiproliferative effect of the tested complex ([Cu(vals) (H(2)O)(3)](2)center dot 6H(2)O) in a dose-response manner, was higher in the UMR106 osteoblastic cell line than that of the MC3T3E1 normal line at concentrations >= 100 mu M. Morphological alterations are in accordance with proliferative observations. (C) 2011 Elsevier Inc. All rights reserved.

Substrate specificity of the Chamaerops excelsa palm tree peroxidase. A steady-state kinetic study

The steady state kinetic mechanism of the H(2)O(2)-supported oxidation of different organic substrates by peroxidase from leaves of Chamaerops excelsa palm trees (CEP) has been investigated. An analysis of the initial rates vs. H(2)O(2) and reducing substrate concentrations is consistent with a substrate-inhibited Ping-Pong Bi Bi reaction mechanism. The phenomenological approach expresses the peroxidase Ping-Pong mechanism in the form of the Michaelis-Menten equation and leads to an interpretation of the effects in terms of the kinetic parameters K(m)(H2O2)center dot K(m)(AH2)center dot k(cat)center dot K(SI)(AH2) and of the microscopic rate constants k(1) and k(3) of the shared three-step catalytic cycle of peroxidases. (C) 2011 Elsevier B.V. All rights reserved.

A tellurium-based cathepsin B inhibitor: Molecular structure, modelling, molecular docking and biological evaluation

The crystallographically determined structure of biologically active 4,4-dichloro-1,3-diphenyl-4-telluraoct-2-en-1-one, 3, shows the coordination geometry for Te to be distorted psi-pentagonal bipyramidal based on a C2OCl3(lone pair) donor set. Notable is the presence of an intramolecular axial Te center dot center dot center dot O (carbonyl) interaction, a design element included to reduce hydrolysis. Raman and molecular modelling studies indicate the persistence of the Te center dot center dot center dot O(carbonyl) interaction in the solution (CHCl3) and gasphases, respectively. Docking studies of 3' (i.e. original 3 less one chloride) with Cathepsin B reveals a change in the configuration about the vinyl C = C bond. i.e. to E from Z (crystal structure). This isomerism allows the optimisation of interactions in the complex which features a covalent Te-SGCys29 bond. Crucially, the E configuration observed for 3' allows for the formation of a hypervalent Te center dot center dot center dot O interaction as well as an O center dot center dot center dot H-O hydrogen bond with the Gly27 and Glu122 residues, respectively. Additional stabilisation is afforded by a combination of interactions spanning the S1, S2, S1' and S2' sub-sites of Cathepsin B. The greater experimental inhibitory activity of 3 compared with analogues is rationalised by the additional interactions formed between 3' and the His110 and His111 residues in the occluding loop, which serve to hinder the entrance to the active site. (C) 2012 Elsevier B.V. All rights reserved.

Crystal structure and spectroscopic properties of polymeric adducts of the tetra-mu-haloaspirinate-dicopper(II)

Eight new copper(II) complexes with halo-aspirinate anions have been synthesized: [Cu-2(Fasp)(4)(MeCN)(2)] center dot 2MeCN (1), [Cu-2(Clasp)(4)(MeCN)(2)]center dot 2MeCN (2), [Cu-2(Brasp)(4) (MeCn)(2)] center dot 2MeCn (3), {[Cu-2(Fasp)(4)(Pyrz)] center dot 2MeCN}(n) (4) {[Cu-2(Clasp)(4)(Pyrz)] center dot 2MeCN}(n) (5), [Cu-2(Brasp)(4)(Pyrz)](n) (6), [Cu-2(Clasp)(4)(4,4'-Bipy)](n) (7), and [Cu-2(Brasp)(4)(4,4'-Bipy)](n) (8) (Fasp: fluor-aspirinate; Clasp: chloro-aspirinate; Brasp: bromo-aspirinate; MeCN: acetonitrile; Pyrz: pyrazine; 4,4'-Bipy: 4,4'-bipyridine). The crystal structure of two 2 and 4 have been determined by X-ray diffraction methods. All compounds have been studied employing elemental analysis, IR, and UV-Visible spectroscopic techniques. The results have been compared with previous data reported for complexes with similar structures.

Low content cerium oxide nanoparticles on carbon for hydrogen peroxide electrosynthesis

A comparative study using different proportions of CeO2/C (4%, 9% and 13% CeO2) was performed to produce H2O2, a reagent used in the oxidation of organic pollutants and in electro-Fenton reactions for the production of the hydroxyl radical (OH center dot), a strong oxidant agent used in the electrochemical treatment of aqueous wastewater. The CeO2/C materials were prepared by a modified polymeric precursor method (PPM). X-ray diffraction analysis of the CeO2/C prepared by the PPM identified two phases. CeO2 and CeO2. The average size of the crystallites in these materials was close to 7 nm. The kinetics of the oxygen reduction reaction (ORR) were evaluated by the rotating ring-disk electrode technique. The results showed that the 4% CeO2/C prepared by the PPM was the best composite for the production of H2O2 in a 1 mol L-1 NaOH electrolyte solution. For this material, the number of electrons transferred and the H2O2 percentage efficiency were 3.1 and 44%, respectively. The ring-current of the 4% CeO2/C was higher than that of Vulcan carbon, the reference material for H2O2 production, which produced 41% H2O2 and transferred 3.1 electrons per molecule of oxygen. The overpotential for this reaction on the ceria-based catalyst was substantially lower (approximately 200 mV), demonstrating the higher catalytic performance of this material. Gas diffusion electrodes (GDE) containing the catalyst were used to evaluate the real amount of H2O2 produced during exhaustive electrolysis. The 4% CeO2/C GDE produced 871 mg L-1 of H2O2, whereas the Vulcan carbon GDE produced a maximum amount of only 407 mg L-1. Thus, the 4% CeO2/C electrocatalyst prepared by the PPM is a promising material for H2O2 electrogeneration in alkaline media. (C) 2011 Elsevier B.V. All rights reserved.

Tuning the reaction products of ruthenium and ciprofloxacin for studies of DNA interactions

This work presents two potential metallo-drugs, the ionic (C17H19FN3O3)(3)[RuCl6]center dot 3H(2)O (1) and the coordination [Ru(C17H17FN3O3)(3)]center dot 4H(2)O (2) compounds, obtained by the combination of ruthenium(III) and ciprofloxacin in different synthetic conditions. The ESI MS spectrum of 1 displayed a main peak at m/z = 994.6, assigned to the gaseous phase adduct (ciprofloxacin)(3)center dot H+, while 2 featured peaks at m/z 1093.3 and 547.1 ascribed to [Ru(C17H17FN3O3)(3)center dot H+-4H(2)O](+) and [Ru(C17H17FN3O3)(3)center dot 2H(+)-4H(2)O](2+). Thermal analysis corroborated the proposed water content for both complexes. Absorption spectra of the compounds in aqueous medium are dominated by ciprofloxacin transitions in the UV region but displayed weak bands in the visible region, assigned to ligand field transitions. The cyclic voltammograms of 2 exhibited a quasi-reversible process ascribed to the Ru(II)/(III) redox pair at -0.25V (vs. SHE) while 1 displayed this process at -0.11 V, showing that the central ruthenium ion is stabilized in the (III) oxidation state by the coordination to the hard oxygen atoms of ciprofloxacin. The solubility of 1 is pH dependent (as well as free ciprofloxacin) while 2 is fully water soluble and stable under physiological pH for at least 48 h. The compounds are also stable under incubation conditions (stomach pH and 37 degrees C) without significant pH lowering. An interaction study of 2 with ct-DNA showed a value of K-b = 2.47 (+/- 0.89) x 10(4) mol(-1) L for the intrinsic binding constant.

Bioaccumulation Of Microcystins In Lettuce

The contamination of lettuce (Lactuca sativa L.) by water-borne crude extracts of the cyanobacterium microcystin-producing Microcystis aeruginosa (Kutzing) Kutzing was investigated. The aim of the study was to determine whether bioaccumulation of microcystins occurs in lettuce foliar tissue when sprayed with solutions containing microcystins at concentrations observed in aquatic systems (0.62 to 12.5 mu g center dot L-1). Microcystins were found in lettuce foliar tissues (8.31 to 177.8 mu g per Kg of fresh weight) at all concentrations of crude extracts. Spraying with water containing microcystins and cyanobacteria may contaminate lettuce at levels higher than the daily intake of microcystins recommended by the World Health Organization (WHO), underscoring the need to monitor such food exposure pathways by public authorities.