New isoniazid complexes, promising agents against mycobacterium tuberculosis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Synthesis, characterization, x-ray structure, DNA cleavage, and cytotoxic activities of palladium(ii) complexes of 4-phenyl-3-thiosemicarbazide and triphenylphosphane

Complexes of the type [PdX(PPh3)(1)]X [1 = 4-phenyl-3- thiosemicarbazide; X = Cl- (2), Br- (3), I- (4), and SCN- (5)] have been synthesized and characterized by elemental analyses and IR, UV/Vis, and 1H and 13C NMR spectroscopy. The molecular structure of complex 4 was determined by single-crystal X-ray diffraction. The binding of the complexes with a purine base (guanosine) was investigated by 1H NMR spectroscopy and mass spectrometry, which showed the complexes to coordinate to guanosine through N7. A gel electrophoresis assay demonstrated the ability of 2-5 to cleave DNA plasmid. All the complexes were tested in vitro by means of the MTT assay for their cytotoxicity against two murine cell lines, LM3 (mammary adenocarcinoma) and LP07 (lung adenocarcinoma), and compared with cisplatin. Complexes 2-5 exhibited good cytotoxicity that surpasses that of cisplatin in the case of LM3. A series of thiosemicarbazide/phosphane palladium(II) complexes have been synthesized and fully characterized. These complexes are able to cleave DNA plasmid and show cytotoxicity against adenocarcinoma (mammary LM3 and lung LP07), surpassing the cytotoxicity of cisplatin in the case of LM3. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis, cytotoxic activity and DNA interaction of Pd(II) complexes bearing N′-methyl-3,5-dimethyl-1-thiocarbamoylpyrazole

A new series of complexes of general formulae [PdX2(tmdmPz)] {X = Cl (1), Br (2), I (3), SCN (4); tmdmPz = N′-methyl-3,5-dimethyl-1- thiocarbamoylpyrazole} have been synthesized and characterized by elemental analysis, molar conductivities, IR, 1H and 13C{ 1H} NMR spectroscopy. In these complexes, the tmdmPz coordinates to Pd(II) center as a neutral N,S-chelating ligand. The geometries of the complexes have been optimized with the DFT method. Cytotoxicity evaluation against LM3 (mammary adenocarcinoma) and LP07 (lung adenocarcinoma) cell lines indicated that complexes 1-4 were more active than cisplatin. The binding of the complexes with a purine base (guanosine) was investigated by 1H NMR and mass spectrometry, showing that the coordination of guanosine occurs through N7. Electrophoretic DNA migration studies showed that all of them modify the DNA tertiary structure. © 2013 Elsevier Ltd. All rights reserved.

Antitumour and anti-inflammatory effects of palladium(II) complexes on Ehrlich tumour

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Synthesis, crystal structures, antimicrobial, antifungal and antituberculosis activities of mixed ligand silver(I) complexes

The biological activity of some new mixed silver-phosphane-thio-ligand complexes, with 1:1:2, 1:1:1 and 1:2:1 (Ag:phospine:ligand) compositions, have been examined. Ten compounds were prepared using a series of silver(I) salts [AgX, where X = NO3, ClO4, PF6 and Br], tertiary phosphines and the ligands thi-osemicarbazide, 2-(propan-2-ylidene) hydrazinecarbothioamide, and thiazolidine-2-thione. The syntheses were carried out under ambient conditions, and the ten complexes obtained were found to be light stable. All 10 compounds were characterized by elemental analysis, FTIR, and NMR spectroscopy, whereas nine compounds were characterized by X-ray diffraction analysis. The anti-proliferative activities were evaluated by minimum inhibitory concentration (MIC: lg/mL) in an aqueous suspension system and they all show promising potential activity against selective strains of Gram-positive and Gram-negative bacteria, fungous and Mycrobaterium tuberculosis H37Rv. © 2013 Elsevier Ltd. All rights reserved.

Silver(I) complexes with symmetrical Schiff bases: Synthesis, structural characterization, DFT studies and antimycobacterial assays

Synthesis, structural and spectroscopic characterizations, molecular modeling and antimycobacterial assays of new silver(I) complexes with two Schiff bases - MBDA and MBDB - are reported. The complexes [Ag(MBDA) 2]NO3, or AgMBDA, and [Ag(MBDB)NO3] or AgMBDB, were obtained by the reaction of the respective ligands with silver(I) nitrate in methanol. The Schiff bases were previously obtained by mixing ethylenediamine or 1,3-diaminopropane with p-anisaldehyde. The characterizations of the complexes were based on elemental (C, H and N) and thermal (TG-DTA) analyses and 13C and 1H NMR and FT-IR spectroscopic measurements, as well as X-ray structure determination for AgMBDA. Spectroscopic data predicted by DFT calculations are in agreement with the experimental data for the AgMBDA complex. The AgMBDA complex has a monomeric structure with a molar proportion 1:2 Ag/ligand, while AgMBDB presents a 1:1 proportion. The complexes AgMBDA and AgMBDB showed to be more effective against Mycobacterium tuberculosis than antibacterial agent silver sulfadiazine - SSD. © 2013 Elsevier Ltd. All rights reserved.

Theoretical investigation of geometric configurations and vibrational spectra in citric acid complexes

The performance of advanced electronic ceramics is directly related to the synthesis route employed. Sol-gel methods are widely used for this purpose. However, the physicochemical intermediate steps are still not well understood. Better understanding and control of these processes can improve the final quality of samples. In this work, we studied theoretically the formation of metal complexes between citric acid and lithium or barium metal cations with different citric acid/metal proportions, using Density Functional Theory electronic structure calculations. Infrared and Raman scattering spectra were simulated for the more stable geometric configurations. Using this methodology, we identified some features of complexes formed in the synthesis process. Our results show that the complexes can be distinguished by changes in the bands assigned to C=O, COH-, and COO- group vibrations. An estimate of the most stable complexes is made based on total energy.

Photochemical transformation of antibiotics by excitation of Fe(III)-complexes in aqueous medium

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Manganese(II) complexes with thiosemicarbazones as potential anti-Mycobacterium tuberculosis agents

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Characterization, inclusion mode, phase-solubility and in vitro release studies of inclusion binary complexes with cyclodextrins and meglumine using sulfamerazine as model drug

In order to investigate the effect on the aqueous solubility and release rate of sulfamerazine (SMR) as model drug, inclusion complexes with beta-cyclodextrin (beta CD), methyl-beta-cyclodextrin (M beta CD) and hydroxypropyl-beta-cyclodextrin (HP beta CD) and a binary system with meglumine (MEG) were developed. The formation of 1: 1 inclusion complexes of SMR with the CDs and a SMR: MEG binary system in solution and in solid state was revealed by phase solubility studies (PSS), nuclear magnetic resonance (NMR), Fourier-transform infrared spectroscopy (FT-IR), thermal analysis and X-Ray diffractometry (XRD) studies. The CDs solubilization of SMR could be improved by ionization of the drug molecule through pH adjustments. The higher apparent stability constants of SMR:CDs complexes were obtained in pH 2.00, demonstrating that CDs present more affinity for the unionized drug. The best approach for SMR solubility enhancement results from the combination of MEG and pH adjustment, with a 34-fold increment and a S-max of 54.8 mg/ml. The permeability of the drug was reduced due to the presence of beta CD, M beta CD, HP beta CD and MEG when used as solubilizers. The study then suggests interesting applications of CD or MEG complexes for modulating the release rate of SMR through semipermeable membranes.

Thermal and spectroscopic studies on solid ibuprofen complexes of lighter trivalent lanthanides

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Cyclodextrin Inclusion Complexes Loaded in Particles as Drug Carrier Systems

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)