Cobalt(II) complexes with disubstituted 3-aminopyrazole derivative: Mononuclear Co(II) complex with in situ prepared formamidine ligand
JOURNAL OF ORGANOMETALLIC CHEMISTRY
Authors: Leovac, Vukadin M.; Tomic, Zoran D.; Kovacs, Attila; Joksovic, Milan D.; Jovanovic, Ljijana S.; Szecsenyi, Katalin Meszaros
Abstract
In the reaction of Co(NO3)(2) center dot 6H(2)O with 4-acetyl-3-amino-5-methylpyrazole (aamp) two octahedral Co(II) complexes, [Co(aamp)2(H2O)(4)](NO3)(2), 1, and [Co(ampf)(MeOH)(2)NO3]NO3 (ampf= N,N'-bis(4-acetyl-5-metliylpyrazole-3-yl)formamidine), 2, were obtained, depending on the reaction conditions. The presence of water in the reaction system leads to incorporation of water molecules into the crystal lattice and I was formed. In all anhydrous environment, due to addition of CH(OEt)3, the fusion of two aamp) was induced through their NH2-groups, incorporating the methine group of CH(OEt)(3). As a result, complex 2, containing an adenino-mimetic NNO pharmacophore ligand, was obtained. The crystal and molecular structure of both compounds was determined. The coordination of aamp in I was achieved through N2 of the pyrazole ring. On the contrary, in 2, an unusual coordination mode of pyrazole is found: one of the pyrazole moieties, due to steric hindrance, coordinates through the oxygen atom of the acetyl group instead of N2. The complexes were characterized by elemental analysis and electronic spectra. For 2 a comprehensive IR spectral analysis is given. The metalligand interactions in 2 are analyzed by quantum chemical computations. The desolvation mechanism of both compounds is discussed in detail. (c) 2007 Elsevier B.V. All rights reserved.
Transdifferentiation Potentiality of Human Wharton's Jelly Stem Cells Towards Vascular Endothelial Cells
JOURNAL OF CELLULAR PHYSIOLOGY
Authors: Alaminos, Miguel; Perez-Koehler, Barbara; Garzon, Ingrid; Garcia-Honduvilla, Natalio; Romer, Beatriz; Campos, Antonio; Bujan, Julia
Abstract
Human Wharton's jelly stem cells (HWJSC) emerged as a potential source of viable cells for use in tissue engineering. In this work, we have analyzed the transdifferentiation capabilities of HWJSC towards transdifferentiated endothelial-like cells (Tr-ELC) in order to establish the potential usefulness of these cells in vascular tissue engineering. Our results show that Tr-ELC became more polygonal and less proliferative than HWJSC, resembling the structure and proliferation rate of the endothelial cells. In addition, the markers of mesenchymal undifferentiation CD9, E-cad, PODXL, and SSEA-4 are downregulated in Tr-ELC, suggesting that these cells can be in the process of adult differentiation. Besides, RT-PCR and microarray analyses revealed that some genes with a role in defining the endothelial phenotype and structure are upregulated (VEGF-R1, EDF1, AAMP, CD31, CD34, CDH5, and ICAM2) or downregulated (VEGF) in Tr-ELC, although a number of genes related to relevant endothelial cell functions (CD36, ECE2, VWF, THBD, PG12, ECE1, and ACE) did not change or were only partially induced. All this implies that HWJSC are able to efficiently transdifferentiate towards Tr-ELC at the phenotypical level following a hierarchical pattern of gene activation, with an earlier induction of morphological and phenotypical genes. J. Cell. Physiol. 223: 640-647, 2010. (C) 2010 Wiley-Liss, Inc.