Showing papers by "Oscar E. Piro published in 2014"
TL;DR: The design, synthesis, and characterization of 82 new compounds aimed at finding appropriate drugs for treating Chagas disease are reported on.
Abstract: Chagas disease, caused by Trypanosoma cruzi parasite, was described thousands of years ago. Currently, it affects millions of people, mostly in Latin America, and there are not suitable drugs for treating it. As an attempt to find appropriate drugs to deal with this problem, we report here on the design, synthesis, and characterization of 82 new compounds. Trypanosomicidal behavior in vitro showed more than 20 outstanding derivatives with anti-Trypanosoma cruzi activity. Furthermore, we studied the nonspecific toxicity against mammalian cells determining their selectivity and also performed mutagenicity studies. Proof of concept, in vivo studies, was conducted with two of the most promising derivatives (77 and 80). They were identified as candidates because they have (i) very simple and cost-effective syntheses; (ii) activity against different stages and strains of the parasite showing excellent in vivo behavior during the acute phase of Chagas disease; and (iii) neither nonspecific toxicity nor mutagenic activity.
42 citations
TL;DR: Telmisartan and CuTlm show antibacterial and antifungal activities in various strains, and Cu tlm displays improved activity against the Staphylococcus aureus strain as compared with unbounded copper(II).
Abstract: A new Cu(II) complex with the antihypertensive drug telmisartan, [Cu8Tlm16]·24H2O (CuTlm), was synthesized and characterized by elemental analysis and electronic, FTIR, Raman and electron paramagnetic resonance spectroscopy. The crystal structure (at 120 K) was solved by X-ray diffraction methods. The octanuclear complex is a hydrate of but otherwise isostructural to the previously reported [Cu8Tlm16] complex. [Cu8Tlm16]·24H2O crystallizes in the tetragonal P4/ncc space group with a = b = 47.335(1), c = 30.894(3) A, Z = 4 molecules per unit cell giving a macrocyclic ring with a double helical structure. The Cu(II) ions are in a distorted bipyramidal environment with a somewhat twisted square basis, cis-coordinated at their core N2O2 basis to two carboxylate oxygen and two terminal benzimidazole nitrogen atoms. Cu8Tlm16 has a toroidal-like shape with a hydrophobic nanometer hole, and their crystal packing defines nanochannels that extend along the crystal c-axis. Several biological activities of the comple...
35 citations
TL;DR: These pyridine-2-thiol 1-oxide derivatives are promising compounds for the treatment of resistant tuberculosis and showed excellent activity, both in the standard strain H37Rv ATCC 27294 (pan-susceptible) and in five clinical isolates that are resistant to the standard first-line anti-tuberculosis drugs isoniazid and rifampicin.
21 citations
TL;DR: In this paper, the structural and conformational properties of two dixanthogen molecules, [CH3(CH2)2OC(S)S]2 and [(CH3)2CHOCS) S]2, were analyzed using a combined experimental and theoretical approach, with data obtained from structural X-ray diffraction methods, IR, Raman and UV-visible spectroscopies, and DFT calculations.
Abstract: Structural and conformational properties of two dixanthogen molecules, [CH3(CH2)2OC(S)S]2 and [(CH3)2CHOC(S)S]2, have been analyzed using a combined experimental and theoretical approach, with data obtained from structural X-ray diffraction methods, IR, Raman and UV-visible spectroscopies, and DFT calculations. [(CH3)2CHOC(S)S]2 crystallizes in the monoclinic P21/c space group with a = 9.735(1) A, b = 12.588(3) A, c = 12.131(2) A, β = 112.65(1)°, and Z = 4 molecules per unit cell. The interactions in the crystal were modelled and interpreted by NBO analysis. [CH3(CH2)2OC(S)S]2 is liquid at room temperature, and the vibrational spectra were satisfactorily explained in terms of the equilibrium between three conformers, originating from the rotation of the two terminal CH3– groups, in agreement with the DFT predictions. The electronic spectra of both dixanthogens were assigned with the assistance of the TD-DFT calculations.
13 citations
TL;DR: Echeverria et al. this article, Gustavo Alberto et al., this article presented a model of the Instituto de Fisica La Plata (IFLP) in Argentina, which is an extension of the Facultad de Ciencias Exactas.
Abstract: Fil: Echeverria, Gustavo Alberto. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - La Plata. Instituto de Fisica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Fisica La Plata; Argentina
11 citations
TL;DR: The assignment and analysis of the frontier HOMO and LUMO orbitals indicate that the absorption bands are mainly originated from π→π(*) transitions.
10 citations
TL;DR: The crystal structure of BaCoO3−δ was determined by X-ray diffraction methods in this article and the structure was solved from 475 reflections with I < 2σ(I) and refined to an agreement R1-factor of 0.0214.
7 citations
TL;DR: Instead of the expected reaction of the nucleophile in a remote point of the molecule, a product resulted from the electrophile character of the thiocarbonyl moiety on the 3-position of the 1,2-dithiole.
Abstract: In the course of our studies on 3H-1,2-dithiole-3-thione synthesis, a serendipitous reactivity with α-haloketones, in the presence of excess of potassium iodide, has been observed. Instead of the expected reaction of the nucleophile in a remote point of the molecule, we have obtained a product resulted from the electrophile character of the thiocarbonyl moiety on the 3-position of the 1,2-dithiole. In order to obtain an efficient protocol in terms of energy efficiency, this methodology was studied under conventional and microwave heating with similar or better results in the latter conditions. Simplicity and great efficiency in this one-step transformation are some of the advantages of this reaction. Moreover, the results can be explained according to the Pearson's hard and soft acid base theory.
6 citations
TL;DR: The calculated HOMO-LUMO energy gap shows that the intra-molecular charge transfer could easily occur, a prediction closely related to the observed bioactivity of this new compound.
3 citations
TL;DR: In this paper, the infrared and Raman spectra of the [Re(CN) 5 NO] 3-complex were reported as guest diluted in the KCl crystal lattice.
2 citations