Synthesis, X-ray characterization and regium bonding interactions of a trichlorido(1-hexylcytosine)gold(iii) complex.

Herein we report the synthesis and X-ray characterization of a gold(iii) complex of 1-hexylcytosine via N(3). The AuCl3N complexes stack on top of each other by reciprocal [AuCl] regium bonding interactions. After the first example 35 years ago, this is the second available structure of a cytosine nucleobase model complexed to gold(iii).

Iridium(III) coordination of N(6) modified adenine derivatives with aminoacid chains.

In this manuscript we report the preparation of three N6-aminoacid-adenine-derivatives: N-(7H-purin-6-yl)glycine·0.5H2O (N6-GlyAde), N-(7H-purin-6-yl)-ß-alanine·1.5H2O (N6-ß-AlaAde) and N-(7H-purin-6-yl)-γ-aminobutyric·2H2O (N6-GabaAde) and the synthesis and X-ray characterization of three Ir(III) NAMI-A derivatives (NAMI-A is [imidazoleH][trans-RuIIICl4(DMSO-κS)(imidazole)]) [trans-IrIIICl4(DMSO-κS)(N3-H)-(7H-purin-6-yl)glycine-κN9] (1), [trans-IrIIICl4(DMSO-κS)(N3-H)-(7H-purin-6-yl)-ß-alanine-κN9] hydrate (2) and [trans-IrIIICl4(DMSO-κS)(N3-H)-(7H-purin-6-yl)-γ-aminobutyryl-κN9] (3). In all complexes the metal center shows octahedral geometry with coordination to four chlorido ligands and one S coordinated dimethylsulfoxide (DMSO-κS). The coordination sphere of the metal is completed by the modified adenine molecule which is bound via N(9) and protonated at N(3). In two complexes the importance of lone pair (lp)-π interactions involving the adenine ring have been studied using density functional theory (DFT) calculations and the Bader's theory of atoms in molecules. Furthermore, the ability of complexes (1-3) to affect the cell viability was evaluated against three different cancer cell lines: human lung carcinoma cells (A549), human cervical carcinoma cells (HeLa) and human breast cancer cells (MCF7). We have also analyzed their ability to cleave the DNA experimentally and their affinity for two models of DNA has been studied using molecular docking simulations.

Synthesis, reactivity, X-ray characterization and docking studies of N7/N9-(2-pyrimidyl)-adenine derivatives.

The reaction of adenine with 2-chloropyrimidine yields as a major product the unexpected N7-(2-pyrimidyl)-adenine (1) and as a minor one N9-(2-pyrimidyl)-adenine (2). Both compounds have been characterized by X-ray diffraction analysis. Moreover, we report the formation of a 1:1 co-crystal (3) composed by compound (1) and adenine that was formed serendipitously during the synthesis of (1). Unexpectedly, the treatment of (1) with Brönsted acids like HCl or HNO3 causes the opening of the imidazole ring of the N7-substituted adenine, yielding N5-(pyrimidin-2-yl)pyrimidine-4,5,6-triamine (4-7) which we have X-ray characterized in its neutral, (4), monoprotonated [nitrate salt (6)] and diprotonated forms [hydrochloride salt (5) and, also, a tetrachlorozincate salt (7)]. Finally, we have used compound (5) as ligand to synthesize and X-ray characterize its complexes with Ir(III) and Ag(I) (compounds (8) and (9), respectively), where the latter is a 2D coordination polymer and the former is a discrete mononuclear complex. We have studied the supramolecular assemblies formed in the solid state by using density functional theory (DFT) calculations. Finally, DNA-docking studies of several compounds have been carried out in order to analyze their ability to interact with the DNA.

X-ray Crystal Structure of a Metalled Double-Helix Generated by Infinite and Consecutive C*-AgI -C* (C*:N1 -Hexylcytosine) Base Pairs through Argentophilic and Hydrogen Bond Interactions.

The synthesis of a metalled double-helix containing exclusively silver-mediated C*-C* base pairs is reported herein (C*=N1 hexylcytosine). Remarkably, it is the first crystal structure containing infinite and consecutive C*-AgI -C* base pairs that form a double helix. The AgI ion occupies the center between two C* residues with N(3)-Ag bond lengths of 2.1 Šand short AgI -AgI distances (3.1 Å) suggesting an interesting argentophilic attraction as a stabilization source of the helical disposition. The solid-state structure is further stabilized by metal-mediated base-pairs, hydrogen bonding and π-stacking interactions. Moreover, the angle N(3)-Ag-N(3) is almost linear in the [Ag(N1 hexylcytosine)2 ]+ motif and the bases are not coplanar, thus generating a double-strand helical aggregate in the solid state. The noncovalent and argentophilic interactions have been rationalized based on DFT calculations.

Crystal structures and DFT calculations of new chlorido-dimethylsulfoxide-M(III) (M = Ir, Ru, Rh) complexes with the N-pyrazolyl pyrimidine donor ligand: kinetic vs. thermodynamic isomers.

New chlorido-dimethylsulfoxide-iridium(III), ruthenium(III) and rhodium(III) complexes with the 2-(1H-pyrazol-1-yl)-pyrimidine (pyrapyr) ligand (OC-6-N1)-[Rh(III)Cl3(DMSO-κS)(pyrapyr)] (1a, N = 3 and 1b, N = 4); (OC-6-N1)-[Ru(III)Cl3(DMSO-κS)(pyrapyr)] (2a, N = 3 and 2b, N = 4) and (OC-6-N1)-[Ir(III)Cl3(DMSO-κS)(pyrapyr)] (3a, N = 3 and 3b, N = 4) have been synthesized and characterized by spectroscopic techniques and by single crystal X-ray diffraction studies (1a, 1b, 2a, 2b, a disordered crystal 3a/3b and a cocrystal 3a·3b). In all cases, the metal centers show octahedral geometry coordinated to three chloride ligands and one S coordinated dimethylsulfoxide (DMSO-κS). The coordination sphere of the metal is completed by the pyrapyr molecule. Two different coordination modes are observed: (i) the DMSO-κS is opposite to the pyrimidinic N atom (IUPAC nomenclature is OC-6-31 denoted herein as trans); (ii) DMSO-κS is opposite to the pyrazolic N atom (IUPAC nomenclature is OC-6-41 denoted as cis). For Rh(III) the kinetic product (cis) yields the thermodynamic (trans) upon heating a solution of the kinetic product and both isomers have been X-ray characterized. Conversely for Ru(III), both kinetic and thermodynamic complexes have been obtained by using different procedures. Both isomers have been characterized by X-ray crystallography and the kinetic product does not yield the thermodynamic upon heating a solution of the former. Furthermore, the Ir(III) behaves differently, since both isomers are energetically equivalent and both isomers co-crystallize in the solid state. The kinetic/thermodynamic mechanism that yields the different isomers has been studied by using theoretical DFT calculations for each metal. Finally, two Ru(II) complexes (OC-6-N1)-[Ru(II)Cl2(DMSO-κS)2(pyrapyr)] (1a, N = 3 and 4b, N = 4) are also described and X-ray characterized. They were obtained as minor products during the synthesis of 2a.

Experimental and theoretical studies on the coordination chemistry of the N1-hexyl substituted pyrimidines (uracil, 5-fluorouracil and cytosine).

N(1)-Hexyl substituted pyrimidines were shown to present solubility properties closer to the real bases than the commonly used methyl and ethyl derivatives, yielding bi-layered structures in the solid state. The study of their coordination capabilities, mainly with Ag(I) and Hg(II), is presented in order to prove their reactivity. A series of coordination complexes, namely, [Hg(N(1)-hexyl-5-fluorouracilate)2]4·6H2O (1), (Ag(+))·[Ag(N(1)-hexyl-5-fluorouracilate)2](-) (2), [Ag(NO3)(N(1)-hexyluracil-κO(4))4] (3), [ZnBr2(N(1)-hexylcytosine)2] (4), [CdBr2(N(1)-hexylcytosine)2] (5), [HgBr2(N(1)-hexylcytosine)2] (6) and [CoBr2(N(1)-hexylcytosine)2] (7), have been synthesized in good yields and X-ray characterized. The presence of the hexyl chains and the fluorine atoms causes the formation of interesting 3D architectures in the solid state. Their structures have been further characterized by infrared spectra (IR) and elemental analyses. In addition, DFT-D3 calculations are used to study interesting noncovalent interactions observed in the solid state, like fluorine-fluorine, fluorine-π and hydrophobic interactions.

Los jóvenes y las jóvenes en el Estado de México: sociodemografía y empleo 2010 / Youngsters from the State of Mexico: socialdemographics and employment 2010 / Os jovens, homens e mulheres no Estado do México: características sociodemográficas e emprego 2010

El presente estudio aborda el tema de los jóvenes mexiquenses de 14 a 29 años de edad que se encuentran en condición de inactividad en el ámbito de lo laboral y educativo, que se integran al recientemente creado concepto de NiNi; el de los jóvenes que ni estudian ni trabajan, la investigación se desarrolló desde una óptica de análisis teórico Socio Antropológico, que permitió observar los componentes mismos del fenómeno, así como, bajo qué especificidades se desarrolla dicho fenómeno. Así, el objetivo del presente artículo, consiste en ofrecer una disertación en torno al actual concepto de NiNi, a partir de información referida, proponiendo como elemento final una conceptualización mucho más acorde a la realidad de la población inmersa en el fenómeno.

This study approaches the topic concerning youngsters from the State of Mexico, with ages ranging from 14 to 29 years who are inactive both in the work and educational fields, who have been integrated to the recent NiNi concept; youngsters who do not study or work. The research is conducted from a Socio-Anthropological theoretical analysis perspective, which allows to observe the components of the phenomenon themselves, as well as under what specificities it develops. Accordingly, its objective consists of offering a dissertation around the current NiNi concept, from referred information, thus proposing, as the final element, a final conceptualization much more in accord with the reality of the population immersed in this phenomenon.

O presente estudo aborda o tema de jovens mexiquenses de 14 e 29 anos de idade que se encontram em condição de inatividade no ámbito do laboral e do educativo que se integram ao recentemente criado conceito de NiNi; os jovens que nem estuam e nem trabalham, a pesquisa de uma ótica de análise téorica sócio-antropológica, que permite observar os componentes mesmos do fenômeno bem como as especificidades que se desenvolvem. Assim, o objetivo do presente artigo, consite em oferecer uma dissertação sobre o atual conceito de NiNi, a partir da informação referida, propondo como elemento final uma conceitualização que esteja muitomais de acordo com a realidade da população imersa no fenómeno.

RNAs' uracil quartet model with a non-essential metal ion.

We have recently communicated the resemblance of 1-hexyluracil in the crystal state with a lipid bilayer (CrystEngComm, 2010, 12, 362-365). Treatment of this molecule with silver nitrate yields a model, using a non-essential metal ion, of a uracil quartet with geometric parameters comparable to those previously found in RNA strands.

Intermolecular C-H...pi interactions in 1,5-diphenyl-3-(2-pyridyl)-2-pyrazoline.

The title compound, C(20)H(17)N(3), is a derivative of 1,3,5-triaryl-2-pyrazoline and can act as an N,N'-bidentate ligand. This molecule features strong fluorescence that can be explained by an extended pyridyl-C=N-N-phenyl system. The three-dimensional structure is formed by means of an extended network of weak C-H...pi hydrogen bonds supported by pi-pi interactions.

Di-µ-chlorido-bis-{chlorido[(R)/(S)-1,5-di-phenyl-3-(2-pyridyl-κN)-2-pyrazoline-κN]zinc(II)}.

In the centrosymmetric binuclear title compound, [Zn(2)Cl(4)(C(20)H(17)N(3))(2)], the coordination geometry of the Zn(II) ion can be described as a distorted ZnN(2)Cl(3) trigonal bipyramid (τ = 0.89), arising from the N,N'-bidentate ligand, a terminal chloride ion and two bridging chloride ions. The N atoms occupy one axial and one equatorial site and the terminal chloride ion occupies an equatorial site. The dihedral angle between the pyridine and pyrazole rings is 12.8 (2)°. In the crystal, aromatic π-π stacking [centroid-centroid separations = 3.812 (3) and 3.848 (3) Å] and C-H⋯Cl and C-H⋯π inter-actions help to establish the packing.

[Histological characteristics of head and neck paragangliomas]. / Anatomía patológica de los paragangliomas cervicocefálicos.

Paragangliomas arise from the extra-adrenal paraganglion system. Histologically, paragangliomas are usually easy to diagnose, with well-defined characteristics. These lesions are clearly delimited and highly vascular and are composed of cell balls (Zellballen) separated by thin fibrous septa. These cell balls are composed of two types of cells: chief cells and sustentacular cells. Other, less frequent patterns, which are nearly always focal, can also be found and hamper diagnosis: angiomatoid, fusocellular and clear cell. Some paragangliomas show intense fibrosis, which can compress and distort the cell balls, giving rise to a pseudoinfiltrative appearance (sclerosing paragangliomas). With immunohistochemical techniques, the chief cells are positive for neuroendocrine markers (neuron specific enolase, chromogranin A, synaptophysin, serotonin) while sustentacular cells are positive for S-100 protein. Ultrastructurally, the chief cells contain neurosecretory granules with dense centers and simple intercellular junctions without desmosomes. From a practical point of view, paragangliomas can be divided into three groups: non-invasive (circumscribed or encapsulated), locally invasive and metastatic. Although some invasive tumors can be fatal, there are no histological data that can predict the malignancy of paragangliomas, and the only absolute criterion for malignancy is the presence of metastasis.

Anatomía patológica de los paragangliomas cervicocefálicos / Histological characteristics of head and neck paragangliomas

Los paragangliomas son tumores que derivan del sistema paragangliónico extra adrenal. Desde el punto de vista histológico, los paragangliomas son, por lo general, tumores de fácil diagnóstico, con unas características bien definidas. Son lesiones bien delimitadas, muy vascularizadas y formadas por nidos celulares (Zellballen) separados por finos septos conjuntivos. Los nidos celulares están constituidos por 2 tipos de células: las principales y las sustentaculares. En ocasiones, existen otros patrones, menos frecuentes y casi siempre focales, que pueden dificultar el diagnóstico: angiomatoide, fusocelular y de células claras. Algunos paragangliomas se acompañan de intensa fibrosis, que puede comprimir y distorsionar los nidos celulares, dando una apariencia seudoinfiltrativa (paragangliomas esclerosantes). Con técnicas inmunohistoquímicas, las células principales son positivas para marcadores neuroendocrinos (enolasaneuronal específica, cromogranina A, sinaptofisina, serotonina) y las células sustentaculares para proteína S-100. Desde el punto de vista ultra estructural, las células principales muestran gránulos de centro denso, de tipo neurosecretor y uniones simples intercelulares sin desmosomas. Desde un punto de vista práctico, los paragangliomas pueden dividirse en 3 grupos: no invasivos (circunscritos o encapsulados), localmente invasivos y metastásicos. A pesar de que algunos tumores de crecimiento infiltrante pueden ser letales, no existe ningún dato histopatológico que pueda predecir el comportamiento maligno de los paragangliomas, y sólo la existencia de metástasis es criterio absoluto de malignidad (AU)

Paragangliomas arise from the extra-adrenal paraganglion system. Histologically, paragangliomas are usually easy to diagnose, with well-defined characteristics. These lesions are clearly delimited and highly vascular and are composed of cell balls (Zellballen) separated by thin fibrous septa. These cell balls are composed of two types of cells: chief cells and sustentacular cells. Other, less frequent patterns, which are nearly always focal, can also be found and hamper diagnosis: angiomatoid, fusocellular and clear cell. Some paragangliomas show intense fibrosis, which can compress and distort the cell balls, giving rise to a pseudo -infiltrative appearance (sclerosing paragangliomas). Withimmunohistochemical techniques, the chief cells are positive for neuroendocrine markers (neuron specific enolase, chromogran in A, synaptophys in, serotonin) while sustentacular cells are positive for S-100 protein. Ultrastructurally, the chief cells contain neurosecretory granules with densecenters and simple intercellular junctions without desmosomes. From a practical point of view, paragangliomas can be divided into three groups: non-invasive (circumscribed or encapsulated), locally invasive and metastatic. Although some invasive tumors can be fatal, there are no histological data that can predict the malignancy of paragangliomas, and the only absolute criterion for malignancy is the presence of metast (AU)

Foliculitis por Trichophyton rubrum (granuloma de Majocchi) / Folliculitis caused by Tricophyton rubrum (Majocchi's granuloma)

El granuloma de Majocchi (también conocido como tinea folicular y granulomatosa) es una infección bien conocida, aunque rara, de la dermis y tejido celular subcutáneo producida por hongos dermatofitos, siendo el más frecuentemente asociado el Trichophyton rubrum. Generalmente ocurre en las piernas de mujeres de edad media y suele precederse de algún factor traumático local. Hemos tenido la oportunidad de ver una mujer de 48 años con antecedentes de onicomicosis en uñas de pie, con una placa en pierna de 4 años de evolución sin clara evidencia de traumatismo previo, en la que se demostró una infección profunda por T. rubrum que remitió tras tratamiento con terbinafina (AU)

Xantogranuloma necrobiótico: a propósito de un caso / Necrobiotic xanthogranuloma: report of a case

El xantogranuloma necrobiótico (XGN) es una entidad clinicopatológica poco frecuente que se incluye dentro de las histiocitosis no X. Clínicamente se caracteriza por pápulas y placas induradas de color rojo-violáceo y localización variable, siendo la región periorbitaria la más frecuente (80% de los casos). Histológicamente se observan en dermis y tejido celular subcutáneo granulomas en empalizada mal delimitados con necrobiosis central y hendiduras de colesterol rodeadas por abundantes células histiocitarias xantomizadas, multinucleadas gigantes, nidos linfocitarios e incluso folículos linfoides dispuestos en la periferia. El hallazgo de laboratorio más constante (80-90%) es la presencia de una paraproteinemia, generalmente gammapatía monoclonal IgG kappa. El curso de la enfermedad es crónico. No existe un tratamiento de elección, aunque el más empleado es el clorambucil. Presentamos el caso de un varón de 69 años que desde los 60 comenzó a presentar placas de color rojo- violáceo en tronco y miembros superiores, con histología diagnóstica de XGN. Las pruebas complementarias objetivaron una paraproteinemia IgG kappa, con una médula ósea sin alteraciones. Aunque han aparecido progresivamente numerosas lesiones, la región periorbitaria nunca se ha afectado. Ha realizado tratamiento con clorambucil con una mejoría parcial (AU)

Complexation of Nickel(II) with Guanosine 5'-Monophosphate and Inosine 5'-Monophosphate: A Potentiometric and Calorimetric Study.

The constants (K(s)) and enthalpies (DeltaH(s)) for stacking interactions between purine nucleoside monophosphates were determined by calorimetry; the values thus obtained were guanosine as follows: K(s) = 2.1 +/- 0.3 M(-)(1) and DeltaH(s) = -41.8 +/- 0.8 kJ/mol for adenosine 5'-monophosphate (5'AMP); K(s) = 1.5 +/- 0.3 M(-1) and DeltaH(s) = -42.0 +/- 1.5 kJ/mol for guanosine 5'-monophosphate (5'GMP); and K(s) = 1.0 +/- 0.2 M(-1) and DeltaH(s) = -42.3 +/- 1.1 kJ/mol for inosine 5'-monophosphate (5'IMP). The interaction of nickel(II) with purine nucleoside monophosphates was studied using potentiometric and calorimetric methods, with 0.1 M tetramethylammonium bromide as the background electrolyte, at 25 degrees C. The presence in solution of the complexes [Ni(5'GMP)(2)](2)(-) and [Ni(5'IMP)(2)](2)(-) was observed. The thermodynamic parameters obtained were log K(ML) = 3.04 +/- 0.02, log K(ML2) = 2.33 +/- 0.02, DeltaH(ML) = -18.4 +/- 0.9 kJ/mol and DeltaH(ML2) = -9.0 +/- 1.9 kJ/mol for 5'GMP; and log K(ML) = 2.91 +/- 0.01, log K(ML2) = 1.92 +/- 0.01, DeltaH(ML) = -16.2 +/- 0.9 kJ/mol and DeltaH(ML2) = -0.1 +/- 2.3 kJ/mol for 5'IMP. The relationships between complex enthalpies and the degree of macrochelation, as well as the stacking interaction between purine bases in the complexes are discussed in relation to previously reported calorimetric data.