33 research outputs found

    A highly enantioselective abiotic receptor for malate dianion in aqueous solution

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    The highly enantioselective molecular recognition of the malate dianion by a synthetic receptor in aqueous solution has been studied by potentiometric titrations, mass spectrometry (ESI-MS), diffusion measurements (PGSE NMR) and molecular modeling.Garcia-España Monsonis, Enrique, [email protected]

    Ditopic Aza-Scorpiand Ligands Interact Selectively with ds-RNA and Modulate the Interaction upon Formation of Zn2+ Complexes

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    Nucleic acids are essential biomolecules in living systems and represent one of the main targets of chemists, biophysics, biologists, and nanotechnologists. New small molecules are continuously developed to target the duplex (ds) structure of DNA and, most recently, RNA to be used as therapeutics and/or biological tools. Stimuli-triggered systems can promote and hamper the interaction to biomolecules through external stimuli such as light and metal coordination. In this work, we report on the interaction with ds-DNA and ds-RNA of two aza-macrocycles able to coordinate Zn2+ metal ions and form binuclear complexes. The interaction of the aza-macrocycles and the Zn2+ metal complexes with duplex DNA and RNA was studied using UV thermal and fluorescence indicator displacement assays in combination with theoretical studies. Both ligands show a high affinity for ds-DNA/RNA and selectivity for ds-RNA. The ability to interact with these duplexes is blocked upon Zn2+ coordination, which was confirmed by the low variation in the melting temperature and poor displacement of the fluorescent dye from the ds-DNA/RNA. Cell viability assays show a decrease in the cytotoxicity of the metal complexes in comparison with the free ligands, which can be associated with the observed binding to the nucleic acids

    X-Ray characterization of 3-methyl-6,8-di(2-pyridyl)-[1,2,3]triazolo[5′,1′:6,1]pyrido[2,3-d]pyrimidine

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    The structure of a new compound 3-methyl-6,8-di(2-pyridyl)[1,2,3]triazolo[5′,1′:6,1]pyrido[2,3- d]pyrimidine 3, formed in the reaction of 3-methyl-[1,2,3]triazolo[1,5-a]pyridine with 2-cyanopyridine, is determined by X-ray diffraction analysis.Abarca Gonzalez, Belen. [email protected] ; Ballesteros Campos, Rafael, [email protected] ; Chadlaoui, Mimoun, [email protected] ; Ramirez de Arellano Sanchez, Maria del Carmen, [email protected]

    Assembly of Polyiodide Networks with Cu(II) Complexes of Pyridinol-Based Tetraaza Macrocycles

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    Polyiodide networks are currently of great practical interest for the preparation of new electronic materials. The participation of metals in the formation of these networks is believed to improve their mechanical performance and thermal stability. Here we report the results on the construction of polyiodide networks obtained using Cu(II) complexes of a series of pyridinol-based tetraazacyclophanes as countercations. The assembly of these crystalline polyiodides takes place from aqueous solutions on the basis of similar structural elements, the [CuL]2+ and [Cu(H-1L)]+ (L = L2, L2-Me, L2-Me3) complex cations, so that the peculiarities induced by the increase of N-methylation of ligands, the structural variable of ligands, can be highlighted. First, solution equilibria involving ligands and complexes were analyzed (potentiometry, NMR, UV-vis, ITC). Then, the appropriate conditions could be selected to prepare polyiodides based on the above complex cations. Single-crystal XRD analysis showed that the coordination of pyridinol units to two metal ions is a prime feature of these ligands, leading to polymeric coordination chains of general formula {[Cu(H-1L)]}nn+ (L = L2-Me, L2-Me3). In the presence of the I-/I2 couple, the polymerization tendency stops with the formation of [(CuL)(CuH-1L)]3+ (L = L2-Me, L2-Me3) dimers which are surrounded by polyiodide networks. Moreover, coordination of the pyridinol group to two metal ions transforms the surface charge of the ring from negative to markedly positive, generating a suitable environment for the assembly of polyiodide anions, while N-methylation shifts the directional control of the assembly from H-bonds to I···I interactions. In fact, an extended concatenation of iodine atoms occurs around the complex dimeric cations, the supramolecular I···I interactions become shorter and shorter, fading into stronger forces dominated by the orbital overlap, which is promising for effective electronic materials

    Cu2+-Induced formation of cage-like compounds containing pyrazole macrocycles

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    The crystal structure of the complex [Cu4(H22L)2(H2O)2- (ClO4)2](ClO4)2·2H2O where L is a new pyrazole ligand containing 1,5-diaminopentane spacers represents a new form of obtaining metal ion-induced inorganic–organic cages.Escarti Alemany, Francisco, [email protected] ; Latorre Saborit, Julio, [email protected] ; Garcia-España Monsonis, Enrique, [email protected]

    Enhancement of SOD activity in boehmite supported nanoreceptors

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    The binuclear Cu2+ complex of a pyridinophane polyamine ligand ranking amongst the fastest SOD mimetics so far reported displays a remarkable SOD activity enhancement when grafted to the surface of boehmite (γ-AlO(OH)) nanoparticles (BNPs)

    Hydrogen-ion driven molecular motions in Cu2+-complexes of a ditopic phenanthrolinophane ligand

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    One of the first kinetic evaluations of a metal ion interchange between the two coordination sites of a ditopic macrocycle is presented.Garcia-España Monsonis, Enrique, [email protected] ; Soriano Soto, Concepción, [email protected] ; Verdejo Viu, Begoña, [email protected]

    Tratamiento quirúrgico de linfedema peneano secundario a hidrosadenitis supurativa

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    Penoscrotal lymphedema is a rare disease in the developed countries, although it is relatively frequent in tropical countries. The most common cause is filariasis, although in our practice usually is associate to neoplasic and inflammatory processes, surgery, radiotherapy, hidroelectrolitic disbalances and idiopathic. We present a 22 years old patient with penoscrotal lymphedema due to hidradenitis suppurativa. After unsuccessful medical treatment, was performed a total excision of the penile skin and subcutaneous tissue to Buck's fascia. Split thickness skin grafts were used to cover the defect. Even medical management of penoscrotal lymphedema is not effective for most patients, surgery is a safe and effective procedure that gives excellent functional and cosmetic results
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