Synthesis and characterization of EDTA complexes useful for trace elements supplementation

The synthesis of two heterobimetallic EDTA complexes, MgCu(EDTA).6H2O and ZnCu(EDTA).6H2O, is described. They were characterized by means of vibrational (infrared and Raman) and electronic (reflectance) spectroscopy. Several dissolution tests in 0.1 N HCl and simulated gastric juice were also performed. The results support the potential usefulness of these complexes for copper supplementation in human and veterinary medicine and to the simultaneous reinforcement of Mg(II) and Zn(II) levels.Facultad de Ciencias Exacta

Co-exposure of the organic nanomaterial fullerene C60 with benzo[a]pyrene in Danio rerio (zebrafish) hepatocytes: Evidence of toxicological interactions

Compounds from the nanotechnology industry, such as carbon-based nanomaterials, are strong candidates to contaminate aquatic environments because their production and disposal have exponentially grown in a few years. Previous evidence shows that fullerene C60, a carbon nanomaterial, can facilitate the intake of metals or PAHs both in vivo and in vitro, potentially amplifying the deleterious effects of these toxicants in organisms. The present work aimed to investigate the effects of fullerene C60 in a Danio rerio (zebrafish) hepatocyte cell lineage exposed to benzo[a]pyrene (BaP) in terms of cell viability, oxidative stress parameters and BaP intracellular accumulation. Additionally, a computational docking was performed to investigate the interaction of the fullerene C60 molecule with the detoxificatory and antioxidant enzyme πGST. Fullerene C60 provoked a significant (p 0.05) alter the enzyme activity when added to GST purified extracts from the zebrafish hepatocyte cells. These results show that fullerene C60 can increase the intake of BaP into the cells, decreasing cell viability and impairing the detoxificatory response by phase II enzymes, such as GST, and this latter effect should be occurring at the transcriptional level.Fil: Ribas Ferreira, Josencler L.. Universidade Federal do Rio Grande do Sul; BrasilFil: Lonné, María Noelia. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: França, Thiago A.. Universidade Federal do Rio Grande do Sul; BrasilFil: Maximilla, Naiana R.. Universidade Federal do Rio Grande do Sul; BrasilFil: Lugokenski, Thiago H.. Universidade Federal de Santa Maria. Departamento de Química; BrasilFil: Costa, Patrícia G.. Universidade Federal do Rio Grande do Sul; BrasilFil: Fillmann, Gilberto. Universidade Federal do Rio Grande do Sul; BrasilFil: Soares, Félix A.. Universidade Federal de Santa Maria. Departamento de Química; BrasilFil: de la Torre, Fernando Roman. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Luján. Departamento de Ciencias Básicas; ArgentinaFil: Monserrat, José María. Universidade Federal do Rio Grande do Sul; Brasil. Instituto Nacional de Ciência e Tecnologia de Nanomateriais de Carbono; Brasi

EPR and magnetic studies of a carboxylate-bridged dinuclear copper(II) compound: [cu2(flu)4(dmf)2]

We report magnetic and EPR (electron paramagnetic resonance) spectroscopy studies of [Cu2(flu)4(dmf)2] (flu = flufenamate and dmf = dimethylformamide), which has CuII ions in tetracarboxylate "paddle wheel" dinuclear units. Susceptibility measurements at 10 < T < 275 K allowed the evaluation of an antiferromagnetic intradinuclear exchange coupling J0 = -294 ± 5 cm-1 between CuII ions (Hex = "J0 S1·S2). EPR experiments at 300 K in powder and single-crystals at 9.5 and 34.4 GHz indicated g// = 2.373, g&#8869; = 2.073 and zero field splitting parameters D = (-0.334 ± 0.001) cm"1 and E ca. 0. EPR signal intensity measurements at X-band in the range 4 < T < 295 K indicated that J0 = "283 ± 5 cm"1. A higher limit |J´| < 5×10-3 cm-1 for the interdinuclear exchange coupling between neighbor units at ca.14.24 Å was estimated from the angular variation of the single crystal spectra around the magic angles. The results are discussed in terms of the structure of the dinuclear unit and the bridges connecting CuII ions and compared with values reported for similar compounds.Reportamos neste trabalho os estudos magnéticos e de RPE do composto [Cu2(flu)4(dmf)2] (flu = flufenamato e dmf = dimetilformamida), tendo os ions CuII como unidades dinucleares em forma de tetracarboxilato "paddle wheel". Medidas de susceptibilidade magnética na faixa de temperatura 10 < T < 275 K permitiram a determinação da energia de interação antiferromagnética J0 = -294 ± 5 cm-1 entre os íons CuII (Hex = "J0 S1·S2 ). Medidas de RPE (espectroscopia de ressonância paramagnética eletrônica) em temperatura ambiente com a amostra em pó e monocristal em bandas X e Q resultaram nos valores g// = 2.373, g&#8869; = 2.073 e parâmetros de campo zero D = (-0.334 ± 0.001) cm"1 e E ca. 0. Medidas com a intensidade integrada do sinal de RPE do monocristal na faixa de temperatura 40 < T < 295 K indicaram o valor de J0 = "283 ± 5 cm"1 . Um limite superior de |J´| < 5×10-3 cm-1 para o acoplamento de intercâmbio entre unidades dinucleares vizinhas a distâncias de ca. 14.24 Å foi estimado com base na variação angular do espectro ao redor do ângulo mágico. Os resultados são discutidos com base na estrutura da unidade dinuclear e das ligações que conectam os íons de CuII, comparando-os com compostos similares descritos na literatura.CNPq - PRONEX/FAPES

Synthesis and characterization of EDTA complexes useful for trace elements supplementation

The synthesis of two heterobimetallic EDTA complexes, MgCu(EDTA).6H2O and ZnCu(EDTA).6H2O, is described. They were characterized by means of vibrational (infrared and Raman) and electronic (reflectance) spectroscopy. Several dissolution tests in 0.1 N HCl and simulated gastric juice were also performed. The results support the potential usefulness of these complexes for copper supplementation in human and veterinary medicine and to the simultaneous reinforcement of Mg(II) and Zn(II) levels.Facultad de Ciencias Exacta

Study of the [Zn(H2O)4CuEDTA]·2H2O Complex, a Potential Trace-metal Supplier: Synthesis, Crystal Structure, Spectroscopic Behavior and Metal Release

Ethylenediaminetetraacetic acid (H4EDTA) is widely used in the pharmaceutical and bromatological industries and as a drug in chelation therapies. Besides, coordinated with metal ions it is used for the supplementation of essential trace elements. In this work the synthesis, crystallographic, and spectroscopic studies (EPR, IR, UV/Vis) of [Zn(H2O)4CuEDTA] · 2H2O are reported. The release of the metal cations at gastric pH was also investigated.Publicado on line en 2014.Centro de Química Inorgánic

Interaction of Cu-dipeptide complexes with Calf Thymus DNA and antiproliferative activity of [Cu(ala-phe)] in osteosarcoma-derived cells

In this work the study of Calf Thymus DNA interaction with several Cu(l-dipeptide) complexes was reported. The binding stoichiometry (Cu(mmol)/DNAmol base) was determined and in an attempt to clarify the binding mode, EPR and CD experiments were performed. All the studied complexes interacted with DNA, in a more selective way than [Cu(H2O)6]2+, being the [Cu(ala-phe)] the complex with the highest interaction. The EPR experiments suggested that the monomeric species formed in solution were coordinated through a nitrogen atom of the DNA bases (inner-sphere binding) and the CD studies showed structural changes upon the DNA–complex interaction. Besides, the ratio Cu(mmol)/DNAmol base obtained by the binding stoichiometry experiments was close to that found by EPR and CD determinations. The effect on cell proliferation determined by the crystal violet bioassay on UMR106 rat osteosarcoma-derived cells showed that the [Cu(ala-phe)] complex exerted an antiproliferative action against this tumor linePEDECIBA Química (Uruguayan organisations)CNPqCONICETUNLPConsejo Superior de Investigaciones Científicas (CSIC

The Mars Environmental Dynamics Analyzer, MEDA: a suite of environmental sensors for the Mars 2020 mission

This is a post-peer-review, pre-copyedit version of an article published in Space science reviews. The final authenticated version is available online at: http://dx.doi.org/10.1007/s11214-021-00816-9NASA’s Mars 2020 (M2020) rover mission includes a suite of sensors to monitor current environmental conditions near the surface of Mars and to constrain bulk aerosol properties from changes in atmospheric radiation at the surface. The Mars Environmental Dynamics Analyzer (MEDA) consists of a set of meteorological sensors including wind sensor, a barometer, a relative humidity sensor, a set of 5 thermocouples to measure atmospheric temperature at ~1.5 m and ~0.5 m above the surface, a set of thermopiles to characterize the thermal IR brightness temperatures of the surface and the lower atmosphere. MEDA adds a radiation and dust sensor to monitor the optical atmospheric properties that can be used to infer bulk aerosol physical properties such as particle size distribution, non-sphericity, and concentration. The MEDA package and its scientific purpose are described in this document as well as how it responded to the calibration tests and how it helps prepare for the human exploration of Mars. A comparison is also presented to previous environmental monitoring payloads landed on Mars on the Viking, Pathfinder, Phoenix, MSL, and InSight spacecraft.Peer ReviewedPostprint (published version

New copper-based complexes with quinoxaline 'N POT.1', 'N POT.4'-dioxide derivatives, potential antitumoral agents

Taking into account our previous studies on cytotoxic metal compounds, new copper complexes with 3-aminoquinoxaline-2-carbonitrile N1,N4-dioxide derivatives as ligands were synthesized and characterized by different spectroscopic methods. The hypoxic selective cytotoxicity towards V79 cells and the superoxide dismutase-like activity of the complexes were determined and related to physicochemical properties of the compounds. In particular, the copper(II) complex with 3-amino-6-chloro-7-fluoroquinoxaline-2-carbonitrile N1,N4-dioxide showed cytotoxic selectivity in hypoxia being the most lipophilic compound of the series. On the contrary, the complex with 3-aminoquinoxaline-2-carbonitrile N1,N4-dioxide was cytotoxic but not selective and that with 3-amino-7-chloro-6-methoxy-quinoxaline-2-carbonitrile N1,N4-dioxide was not cytotoxic towards V79 cells neither in oxia nor in hypoxia in the assayed conditions. The σm Hammett substituent electronic descriptor was related to the effect in hypoxic conditions and the SOD-like activity was correlated to the effect in normoxia.Comisión Honoraria de Lucha Contra el Cáncer (CHLCC)Comisión Sectorial de Investigación Científica (CSIC)PEDECIB