Publicaciones

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Tarazona J.V, Rodríguez C, Alonso E, Sáez M, González F, San Andrés M.D, Jiménez B., San Andrés M.I.
Toxicology Letters, vol. 241, pags. 200 - 206 (2016)
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This article describes the toxicokinetics of perfluorooctane sulfonate (PFOS) in rabbits under low repeated dosing, equivalent to 0.085. μg/kg per day, and the observed differences between rabbits and chickens. The best fitting for both species was provided by a simple pseudo monocompartmental first-order kinetics model, regulated by two rates, and accounting for real elimination as well as binding of PFOS to non-exchangeable structures. Elimination was more rapid in rabbits, with a pseudo first-order dissipation half-life of 88 days compared to the 230 days observed for chickens. By contrast, the calculated assimilation efficiency for rabbits was almost 1, very close to full absorption, significantly higher than the 0.66 with confidence intervals of 0.64 and 0.68 observed for chickens. The results confirm a very different kinetics than that observed in single-dose experiments confirming clear dose-related differences in apparent elimination rates in rabbits, as previously described for humans and other mammals; suggesting the role of a capacity-limited saturable process resulting in different kinetic behaviours for PFOS in high dose versus environmentally relevant low dose exposure conditions. The model calculations confirmed that the measured maximum concentrations were still far from the steady state situation, and that the different kinetics between birds and mammals should may play a significant role in the biomagnifications assessment and potential exposure for humans and predators. For the same dose regime, the steady state concentration was estimated at about 36. μg PFOS/L serum for rabbits, slightly above one-half of the 65. μg PFOS/L serum estimated for chickens. The toxicokinetic parameters presented here can be used for higher-tier bioaccumulation estimations of PFOS in rabbits and chickens as starting point for human health exposure assessments and as surrogate values for modeling PFOS kinetics in wild mammals and bird in exposure assessment of predatory species. © 2015.
García-Bermejo Á, Mohr S, Herrero L, González M.-J, Gómara B
Journal of Agricultural and Food Chemistry, vol. 64, nº 38, pags. 7265 - 7274 (2016)
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This paper reports on the optimization, characterization, and applicability of gas chromatography coupled to triple-quadrupole tandem mass spectrometry (GC-QqQ(MS/MS)) for the determination of 14 polybrominated diphenylethers (PBDEs) and 2 emerging brominated flame retardants, 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) and decabromodiphenylethane (DBDPE), in functional food samples. The method showed satisfactory precision and linearity with instrumental limits of detection (iLODs) ranging from 0.12 to 7.1 pg, for tri- to octa-BDEs and BTBPE, and equal to 51 and 20 pg for BDE-209 and DBDPE, respectively. The highest ΣBFR concentrations were found in fish oil supplements (924 pg/g fresh weight, fw), followed by biscuits (90 pg/g fw), vegetable oil supplements (46 pg/g fw), chicken eggs (45 pg/g fw), cow's milk (7.7 pg/g fw), and soy products (1.6 pg/g fw). BDE-47, BDE-99, and DBDPE were the most abundant compounds. Foodstuffs enriched with omega-3 presented concentrations similar to or even lower than those of conventional foods commercialized in Spain since 2000. © 2016 American Chemical Society.
De Miguel I, Morales E., Herradón B, del Río C, Mann E
Tetrahedron Letters, vol. 57, nº 30, pags. 3291 - 3293 (2016)
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Two series of thiazolium bis(trifluoromethylsulfonyl)imide [NTf2] room temperature ionic liquids (RTILs) functionalized with oligo(oxyethylene)-chains have been synthesized in multigram scale and characterized. Their thermal properties and conductivity values have been determined. The increase in the number and length of the oligo(oxyethylene)-chains attached to the thiazolium ring resulted in lower values of ionic conductivity. © 2016 Elsevier Ltd
Colomer I, Gheewala C, Simal C, Velado M, Fernández De La Pradilla R, Viso A.
Journal of Organic Chemistry, vol. 81, nº 10, pags. 4081 - 4087 (2016)
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Sulfinyl trichloroacetamides are readily obtained in excellent yields through a highly stereoselective Overman rearrangement. Related bis-allylic substrates lead to amido 2-sulfinyl butadiene derivatives in excellent yields, with total chemo- and diastereoselectivity. These amido dienyl sulfoxides undergo highly selective Diels-Alder cycloadditions with N-phenylmaleimide with remarkable stereocontrol by the sulfoxide moiety. © 2016 American Chemical Society.
Balmaña M, Giménez E, Puerta A, Llop E, Figueras J, Fort E, Sanz-Nebot V, de Bolós C, Rizzi A, Barrabes S, de Frutos M., Peracaula R
Journal of Proteomics, vol. 132, pags. 144 - 154 (2016)
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Pancreatic cancer (PDAC) lacks reliable diagnostic biomarkers and the search for new biomarkers represents an important challenge. Previous results looking at a small cohort of patients showed an increase in α-1-acid glycoprotein (AGP) fucosylation in advanced PDAC using N-glycan sequencing. Here, we have analysed AGP glycoforms in a larger cohort using several analytical techniques including mass spectrometry (MS), capillary zone electrophoresis (CZE) and enzyme-linked lectin assays (ELLAs) for determining AGP glycoforms which could be PDAC associated. AGP from 31 serum samples, including healthy controls (HC), chronic pancreatitis (ChrP) and PDAC patients, was purified by immunoaffinity chromatography. Stable isotope labelling of AGP released N-glycans and their analysis by zwitterionic hydrophilic interaction capillary liquid chromatography electrospray MS (μZIC-HILIC-ESI-MS) showed an increase in AGP fucosylated glycoforms in PDAC compared to ChrP and HC. By CZE-UV analysis, relative concentrations of some of the AGP isoforms were found significantly different compared to those in PDAC and HC. Finally, ELLAs using Aleuria aurantia lectin displayed a significant increase in AGP fucosylation, before and after AGP neuraminidase treatment, in advanced PDAC compared to ChrP and HC, respectively. Altogether, these results indicate that α1-3 fucosylated glycoforms of AGP are increased in PDAC and could be potentially regarded as a PDAC biomarker. © 2015 Elsevier B.V.
Martínez-Sáez N, Supekar N.T, Wolfert M.A, Bermejo I.A, Hurtado-Guerrero R, Asensio J.L, Jiménez-Barbero J, Busto J.H, Avenoza A, Boons G.-J, Peregrina J.M, Corzana F.
Chemical Science, vol. 7, nº 3, pags. 2294 - 2301 (2016)
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A tripartite cancer vaccine candidate, containing a quaternary amino acid (α-methylserine) in the most immunogenic domain of MUC1, has been synthesized and examined for antigenic properties in transgenic mice. The vaccine which is glycosylated with GalNAc at the unnatural amino acid, was capable of eliciting potent antibody responses recognizing both glycosylated and unglycosylated tumour-associated MUC1 peptides and native MUC1 antigen present on cancer cells. The peptide backbone of the novel vaccine presents the bioactive conformation in solution and is more resistant to enzymatic degradation than the natural counter part. In spite of these features, the immune response elicited by the unnatural vaccine was not improved compared to a vaccine candidate containing natural threonine. These observations were rationalized by conformational studies, indicating that the presentation and dynamics of the sugar moiety displayed by the MUC1 derivative play a critical role in immune recognition. It is clear that engineered MUC1-based vaccines bearing unnatural amino acids have to be able to emulate the conformational properties of the glycosidic linkage between the GalNAc and the threonine residues. The results described here will be helpful to the rational design of efficacious cancer vaccines. © The Royal Society of Chemistry 2016.
Dgachi Y, Ismaili L., Knez D, Benchekroun M, Martin H, Szałaj N, Wehle S, Bautista-Aguilera O.M, Luzet V, Bonnet A, Malawska B, Gobec S, Chioua M, Decker M, Chabchoub F, Marco-Contelles J.
ChemMedChem, pags. 1318 - 1327 (2016)
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Given the complex nature of Alzheimer′s disease (AD), compounds that are able to simultaneously address two or more AD-associated targets show greater promise for development into drugs for AD therapy. Herein we report an efficient two-step synthesis and biological evaluation of new racemic benzochromene derivatives as antioxidants, inhibitors of cholinesterase and β-amyloid (Aβ1−42) aggregation. Based on the results of the primary screening, we identified 15-(3-methoxyphenyl)-9,11,12,15-tetrahydro-10H,14H-benzo[5,6]chromeno[2,3-d]pyrido[1,2-a]pyrimidin-14-imine (3 e) and 16-(3-methoxyphenyl)-9,10,11,12,13,16-hexahydro-15H-benzo[5′,6′]chromeno[2′,3′:4,5]pyrimido[1,2-a]azepin-15-imine (3 f) as new potential multitarget-directed ligands for AD therapy. Further in-depth biological analysis showed that compound 3 f is a good human acetylcholinesterase inhibitor [IC50=(0.36±0.02) μm], has strong antioxidant activity (3.61 μmol Trolox equivalents), and moderate Aβ1−42antiaggregating power (40.3 \%). © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Alcaide B, Almendros P, Aragoncillo C, Gómez-Campillos G, Quirós M.T, Soriano E
Journal of Organic Chemistry, vol. 81, nº 17, pags. 7362 - 7372 (2016)
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Controlled preparation of 2,5-dihydro-1H-pyrroles, 3,6-dihydro-2H-pyrans, and pyrroles has been achieved through switchable chemo- and regioselectivity in the metal-catalyzed heterocyclization reactions of allenic amino alcohols. The gold-catalyzed cycloisomerization reaction of α-amino-β-hydroxyallenes was effective as 5-endo cyclization by addition of amino functionality to the distal allene carbon to yield enantiopure 2,5-dihydro-1H-pyrroles, whereas their palladium-catalyzed cyclizative coupling reactions furnished 3,6-dihydro-2H-pyrans through a chemo- and regioselective 6-endo cycloetherification. Conversely, the gold-catalyzed heterocyclization reaction of β-amino-γ-hydroxyallenes generated exclusively pyrrole derivatives. These results could be explained through a chemo- and regioselective 5-exo aminocyclization to the central allene carbon followed by aromatization. Chemo- and regioselectivity depend on both linker elongation as well as the type of catalyst. This behavior can be justified by means of density functional theory calculations. © 2016 American Chemical Society.
Frutos M, Avello M.G, Viso A., Fernández De La Pradilla R, de la Torre M.C, Sierra M.A, Gornitzka H, Hemmert C.
Organic Letters, vol. 18, nº 15, pags. 3570 - 3573 (2016)
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Gold mesoionic carbenes having a chiral sulfoxide group attached to the C4 position of the five membered ring have been prepared and tested as catalysts in the cycloisomerization of enynes. These new catalysts are very efficient, with the sulfoxide moiety playing a key role in their activity and the N1-substituent in control of the regioselectivity of these processes. © 2016 American Chemical Society.
Gómez A.M, Lobo F, López J.C.
Carbohydrate Chemistry, vol. 41, pags. 26 - 58 (2016)
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The presence of an unsaturation in a pyranose derivative provides a powerful handle for the creation of new compounds displaying a variety of molecular skeletons. This contribution focuses on investigations related to the use of pyranose glycals in the creation of skeletally-diverse derivatives that have appeared in the literature during the last eight years. © The Royal Society of Chemistry 2016.
Romero A, Ramos E., Patiño P, Oset-Gasque M.J, López-Muñoz F, Marco-Contelles J.
Frontiers in Aging Neuroscience, vol. 8, nº NOV (2016)
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Stroke is a disease of aging affecting millions of people worldwide, and recombinant tissue-type plasminogen activator (r-tPA) is the only treatment approved. However, r-tPA has a low therapeutic window and secondary effects which limit its beneficial outcome, urging thus the search for new more efficient therapies. Among them, neuroprotection based on melatonin or nitrones, as free radical traps, have arisen as drug candidates due to their strong antioxidant power. In this Perspective article, an update on the specific results of the melatonin and several new nitrones are presented. © 2016 Romero, Ramos, Patiño, Oset-Gasque, López-Muñoz and Marco-Contelles.
Pérez Mayoral E, Calvino-Casilda V, Soriano E
Catalysis Science and Technology, vol. 6, nº 5, pags. 1265 - 1291 (2016)
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Carbon materials such as activated carbons and graphitic materials and nanomaterials have been used for decades in heterogeneous catalysis as catalyst supports. The physical and chemical properties of these materials, such as their tunable porosity and surface chemistry, allow the anchoring and dispersion of the active phases, and make them suitable for application in many catalytic green processes. In this review, we summarize relevant applications and limitations of metal-supported carbons and nanocarbons in the synthesis of valuable products and the recent advances in this field. © 2016 The Royal Society of Chemistry.
Castro-Jiménez J, González-Gaya B, Pizarro M, Casal P, Pizarro-Álvarez C, Dachs J.
Environmental Science and Technology, vol. 50, nº 23, pags. 12831 - 12839 (2016)
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Organophosphate esters (OPEs) are widely used as flame retardants and plasticizers and have been detected ubiquitously in the remote atmosphere. Fourteen OPEs were analyzed in 115 aerosol phase samples collected from the tropical and subtropical Atlantic, Pacific, and Indian Oceans during the MALASPINA circumnavigation campaign. OPEs were detected in all samples with concentrations ranging from 360 to 4400 pg m -3 for the sum of compounds. No clear concentration trends were found between the Northern and Southern hemispheres. The pattern was generally dominated by tris(1-chloro-2-propyl) phosphate (TCPP), although tri-n-butyl phosphate (TnBP) had a predominant role in samples close to continents and in those influenced by air masses originating in continents. The dry deposition fluxes of aerosol phase Σ 14 OPE ranged from 4 to 140 ng m -2 d -1 . An estimation of the OPE gas phase concentration and gross absorption fluxes by using three different sets of physical chemical properties suggested that the atmosphere-ocean diffusive exchange of OPEs could be 2-3 orders of magnitude larger than dry deposition. The associated organic phosphorus inputs coming from diffusive OPE fluxes were estimated to potentially trigger up to 1.0\% of the reported primary production in the most oligotrophic oceanic regions. However, the uncertainty associated with these calculations is high and mostly driven by the uncertainty of the physical chemical properties of OPEs. Further constraints of the physical chemical properties and fluxes of OPEs are urgently needed, in order to estimate their environmental fate and relevance as a diffusive source of new organic phosphorus to the ocean. (Figure Presented). © 2016 American Chemical Society.
Rangel-Rangel E, Verde-Sesto E, Rasero-Almansa A.M, Iglesias M, Sánchez F
Catalysis Science and Technology, vol. 6, nº 15, pags. 6037 - 6045 (2016)
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Porous polymeric aromatic frameworks (PAFs) have high porosity and surface area, as well as high physicochemical stability; such characteristics are important in the design of heterogeneous catalysts with high catalytic efficiency and recyclability. This paper presents the synthesis, characterization, post-functionalization and catalytic performance of the resulting modified PAFs based on tetraphenyladamantane (PAFAd), tetraphenylmethane (PAFC) and 9,9′-spirobisfluorene (PAFspf) nodes. The PAFs were obtained by the Suzuki-Miyaura cross-coupling under microwave heating, and were sequentially reacted with 1-(chloromethoxy)octane and 1-mesityl-1H-imidazole or 2-(1H-imidazol-1-yl)pyridine to yield the corresponding imidazolium chloride derivative (PAF-Im) which readily formed stable N-heterocyclic carbene (NHC) iridium and ruthenium complexes (PAF-(NHC)Ir, PAF-(NHC)Ru). The materials were characterized by solid-state NMR spectroscopy, FTIR spectroscopy, and textural analysis. The PAF-(NHC)M materials display excellent catalytic performance in the N-alkylation of amines with alcohols and transfer hydrogenation of ketones over multiple catalytic cycles. © 2016 The Royal Society of Chemistry.
Liras M, Pintado-Sierra M, Iglesias M, Sánchez F
Journal of Materials Chemistry A, vol. 4, nº 44, pags. 17274 - 17278 (2016)
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This work shows that a deprotection strategy of BODIPY conjugated porous polymers (CMPBDPs) can be successfully applied to synthesize a new (dipyrrin)(bipyridine)Ru(ii) (CMPBDP-Ru) efficient heterogeneous photocatalyst for iminium ion generation under visible light. CMPBDP-Ru shows high thermal and photochemical stability under irradiation, and it could be reused several times. © The Royal Society of Chemistry 2016.
Alcaide B, Almendros P, Martín-Montero R, Ruiz M.P.
Advanced Synthesis and Catalysis, vol. 358, nº 9, pags. 1469 - 1477 (2016)
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The present study provides insights into the manner in which the configuration of β-aminoallene precursors affects their gold-catalyzed cyclization reactions. The reactivity can be switched by using indolizidinone-tethered β-aminoallenes bearing the syn- or the anti-disposition of both protons at the α- and β-allenic stereocenters. Fused heterocycles (seven examples, 60-75\% yields) are obtained from the syn-precursors, while a dimerization-aminoketalization-spirocyclization sequence to afford benzo[b]pyrrolo[3,2,1-ij][1,7]naphthyridin-1-ones (four examples, 34-48\% yields) can be achieved starting from their anti-isomers. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Alcaide B, Almendros P, Busto E, Luna A.
Advanced Synthesis and Catalysis, vol. 358, nº 9, pags. 1526 - 1533 (2016)
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A method for the arylative coupling of alkynols or alkynyl hydroperoxides using equimolar amounts of diazonium salts at room temperature has been achieved through application of a gold/photoredox dual catalytic system. The excess of external reagents (oxidant or base) and high temperatures required by previous arylative Meyer-Schuster rearrangement protocols are avoided by exploitation of a visible light-mediated process. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Alcaide B, Almendros P, González A.M, Luna A., Martínez-Ramírez S.
Advanced Synthesis and Catalysis, vol. 358, nº 12, pags. 2000 - 2006 (2016)
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A convenient ligand-free catalytic system has been developed for the chemoselective cyclization reaction of various α-allenol derivatives by palladium nanoparticles (PdNPs) in an aqueous reaction medium. (Figure presented.) . © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Alcaide B, Almendros P, Aragoncillo C, Fernández I, Gómez-Campillos G
Chemistry - A European Journal, vol. 22, nº 1, pags. 285 - 294 (2016)
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The controlled metal-free preparation of fused δ-sultone derivatives has been developed starting from hydroxyallenynes. The use of 2-(3,3-diethyltriaz-1-enyl)-4-methylbenzene-1-sulfonyl chloride in a sulfonylation/rearrangement sequence gives access to 1,3-dien-2-yl arenesulfonates. These functionalized enynes suffered a direct cyclization/desaturation radical cascade, allowing the synthesis of a variety of enynyl [1,2]oxathiine 1,1-dioxides. Stereoselective cyclization of the readily formed core through intramolecular Diels-Alder reaction has also been demonstrated, affording β-lactam- and glucofuranoside-fused δ-sultone polycycles. These selective reactions have been studied experimentally and additionally, their reaction mechanisms have been investigated computationally by means of density functional theory calculations. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
Koenka I.J, Mai T.D., Hauser P.C, Sáiz J
Analytical Methods, vol. 8, nº 7, pags. 1452 - 1456 (2016)
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In this review, the simultaneous determination of anionic and cationic species in capillary electrophoresis for different applications such as water quality analysis, medical diagnosis, pharmaceutical analysis, forensic science and food control is discussed. The simplicity and electronic nature of capillary electrophoresis allow the easy modification of custom made set-ups in order to realise various techniques for the simultaneous separation of different ionic analytes. As a continuation of our earlier review, in which the details of the working principles were described, this report is focussed on the applications of the simultaneous electrokinetic separation methods reported during the last five years (2011-2015). © The Royal Society of Chemistry 2016.