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In the present work, different ferrite-type nanoparticles (Ni0.5Zn0.5Fe2O4, NiFe2O4 and Fe3O4) were incorporated into an epoxy resin to obtain composites loaded with 20 and 40 wt% of filler. The morphology of these monolayered composites was investigated by small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM), which allow identifying a fractal structure of the ferrite-based filler with rough surface. The electromagnetic properties of the monolayer composites with 1 mm thickness were evaluated by the transmission line method in X-band (8.2–12.4 GHz), whose better response in terms of reflection loss was obtained for the composite filled with Ni0.5Zn0.5Fe2O4. Epoxy-based composites containing 20 and 40 wt% of Ni0.5Zn0.5Fe2O4 in the form of plaques were arranged in two types of three-layered structures: (i) stacked monolayers and (ii) low dielectric spacer sandwiches between monolayers (air, honeycomb and foam), whose structure sequence was built based on the reflectivity simulation. The best system, designed by mathematical simulation and experimental results, consisted of ER/NiZn(40)–honeycomb–ER/NiZn(20) arrangement, which presented RL of around − 40 dB at a frequency of 8.75 GHz. Broadband with > 90% attenuation (minimum of − 10 dB) with band width of around 1.2 GHz and minimum RL ≈ 20 dB (Eabs ≈ 99%) was achieved for both three-layered structures contain in PU foam or honeycomb as low dielectric spacer. The ferrite-based multilayer structures with only 6 mm of thickness constitute promising absorbing materials for applications in both civil and military fields.

Cetylpyridinium chloride (CPC) is a cationic surfactant, which has a biocidal activity against a broad spectrum of bacteria, including Staphylococcus aureus. This microorganism, although frequently found in the normal human microbiota, can become a pathogen that causes a wide variety of infections. Thus, the present work aims to investigate the effect of the β-cyclodextrin (βCD) on CPC antimicrobial activity against S. aureus, especially in the mechanism of interaction with S. aureus membrane. For these purposes, in vitro antimicrobial susceptibility of CPC and CPC/βCD compounds against S. aureus were determined by calculating the lower concentration capable of reducing cell viability by 50 and 100 percent, and the kinetics of bacterial death were evaluated by kill curves for the two systems. After that, the colloidal mechanisms of interaction of the CPC and CPC/βCD against S. aureus were investigated by Dynamic Light Scattering (DLS) and Zeta Potential (ZP) titrations. Finally, the thermodynamic parameters of drug-cell interaction were determined by Isothermal Titration Calorimetry (ITC), in order to obtain deeper understanding of the mechanism of drug interactions. The results of DLS, ZP and ITC showed that in presence of βCD occurs a different mechanism of interaction with S. aureus membrane, explaining therefore the higher antimicrobial activity of CPC/βCD system.

This study searched for a new pre-formulation based on the natural compound from the class of the avermectins, named abamectin (ABA), in order to improve its action against Aedes aegypti larvae by complexation with β-cyclodextrin (βCD). Concerning the low aqueous solubility of ABA, even in the presence of βCD, it was also invoked the strategy of working with hydrophobic nanoprecipitates (HNPs). For these purposes, molecular and supramolecular characterizations of 1:1 ABA/βCD complex and evaluation of its toxicity against A. aegypti larvae were performed. In the physical-chemistry characterizations, changes in the infrared spectra and thermal profiles in relation to precursors confirmed the occurrence of interactions between ABA and βCD in solid state. Nuclear magnetic resonance (NMR) data suggest the inclusion of ABA in βCD via benzofuran ring. Isothermal titration calorimetry (ITC) experiments allowed to verify the formation of complex with a 1:1 stoichiometry, which was entropy driven. The dynamic light scattering and zeta potential data from inclusion compounds demonstrated changes in the size of the ABA/βCD HNP if compared with the ABA HNP. Finally, the results for biological assays demonstrate that the strategy to prepare the inclusion compound led to an increase in the larvicidal activity in relation to free ABA.

In the present work we have performed a structural and thermodynamic characterization of supramolecular structures formed by interaction between cethylpyridine chloride (CPC) surfactant and β-cyclodextrin (βCD), using several physical-chemistry methods. Initially, qualitative CPC/βCD interactions in solid state were confirmed by FTIR and TGA/DTA. 2D NMR ROESY experiment showed strong correlations between hydrogens of βCD cavity with aromatic and aliphatic hydrogens of CPC, suggesting the existence of different complexes in solution. This information was corroborated by structures assessed by computational approach and stoichiometric coefficient obtained by ITC (N = 1.45). ITC experiments (at constant concentration of CPC) also showed that host-guest complexation occur with very high binding constant (Kb = 38,300.0), and driven by enthalpy and entropy. However, as CPC is an amphiphilic molecule, it is able to form micelles at critical micellar concentration close to 1 mM. In presence of βCD, it was observed that micellization was delayed, so that the cmc values increased according to the empiric equation: cmc = 1.02 + 0.5[βCD]. Moreover, thermodynamic data obtained by combination of conductometric and isothermal calorimetry titrations showed that the presence of increasing concentrations of βCD causes an increase of free energy of micellization, specially by gradual reduction of entropy of micellization, due to the difficult of micelles encapsulate the inclusion compounds. The overall study was rationalized in terms of competition between micellization vs. host-guest complexation.

Three imidazole hydrazone compounds, namely 2-(4-nitro-1H-imidazol-1-yl)-N′-[1-(pyridin-2-yl)ethylidene]acetohydrazide, C12H12N6O3, (1), 2-(2-nitro-1H-imidazol-1-yl)-N′-[1-(pyridin-2-yl)ethylidene]acetohydrazide, C12H12N6O3, (2), and 2-(2-nitro-1H-imidazol-1-yl)-N′-[(phenyl)(pyridin-2-yl)methylidene]acetohydrazide, C17H14N6O3, (3), were obtained and fully characterized, including their crystal structure determinations. While all the compounds proved not to be cytotoxic to J774.A1 macrophage cells, (1) and (3) exhibited activity against Leishmania chagasi, whereas (2) was revealed to be inactive. Since both (1) and (3) exhibited antileishmanial effects, while (2) was devoid of activity, the presence of the acetyl or benzoyl groups was possibly not a determining factor in the observed antiprotozoal activity. In contrast, since (1) and (3) are 4-nitroimidazole derivatives and (2) is a 2-nitroimidazole-derived compound, the presence of the 4-nitro group probably favours antileishmanial activity over the 2-nitro group. The results suggested that further investigations on compounds (1) and (3) as bioreducible antileishmanial prodrug candidates are called for.

In this work is reported the synthesis, characterization, luminescent properties and positronium formation yields of europium(III) and terbium(III) complexes of stoichiometric formula Ln(dpm)3(2-pyr), where: Ln = Eu and Tb, dpm = 2,2,6,6-tetramethyl-3,5-heptanedionato (dipivaloylmethanate) ion, a β-diketonate ligand, and 2-pyr = 2-pyrrodilidone, a γ-lactam. The crystal structures were determined by single-crystal X-ray diffraction. The complexes crystallize in the space group Pī with one complex in the asymmetric unit. The Eu(III) and Tb(III) ions are seven-coordinated by six O atoms of three β-diketonate ligands, and one O atom of γ-lactam molecule. We present and discuss experimental intensity parameters of 4f-4f transitions in the Eu(III) complexes under UV excitation. The photoluminescent properties of the complexes depend on the energy positions of the ligand-to-metal charge transfer (LMCT) states. The temperature dependence of the Eu(III) 5D0 relaxation rate of the Eu(III) complexes are presented. Positronium formation in Ln(dpm)3 and Ln(dpm)3(2-pyr) (Ln = Eu and Tb) complexes were investigated. A correlation between the parameters of luminescence and positron annihilation spectroscopies has been observed. The results, which strongly evidence the participation of molecular excited states in the positronium formation, were then discussed in terms of the recently proposed Ps formation mechanism, named cybotactic correlated system kinetic mechanism (CCSKM).

The ofloxacin (OFLOX) is a second-generation synthetic antibiotic that can be classified as a multifunctional drug, but is a poorly soluble drug, which influences its efficiency. The inclusion complexes of OFLOX with β-cyclodextrin (βCD) or hydroxypropyl-β-cyclodextrin (HPβCD) can improve the chemical characteristics of the drug; however, studies showing the biological activity of these inclusion complexes are still scarce. The present work aimed to investigate the multifunctionality of the OFLOX and their inclusion complexes. Thus, the 1:1 βCD/OFLOX or HPβCD/OFLOX were prepared and analyzed by Fourier transform infrared spectroscopy (FTIR), thermogravimetric and differential thermal analysis (TGA and DTA), 1H nuclear magnetic resonance (NMR) and isothermal titration calorimetry (ITC). The antitumor and antibacterial effects were assessed. The results confirm the formation of the inclusion complexes, which had lower minimum inhibitory concentration (MIC) values, higher cytotoxicity and promoted the apoptosis. The present study showed, for the first time, the promising effects of the inclusion complexes as antitumor, improving the biological activities of the uncomplexed ofloxacin.

Complexes [In(2Ac4Ph)2]NO3·H2O (1), [In(2Ac4mClPh)2]NO3·1.5H2O (2), [In(2Ac4pClPh)2]NO3·2H2O (3) and [In(2Ac4pIPh)2]NO3·H2O (4) were obtained with N(4)-phenyl-2-acetylpyridine thiosemicarbazone (H2Ac4Ph), and its N(4)-meta-chlorophenyl-(H2Ac4mClPh), N(4)-para-chlorophenyl-(H2Ac4pClPh) and N(4)-para-iodophenyl-(H2Ac4pIPh) derivatives. The crystal structures of [In(2Ac4Ph)2]NO3·MeOH (1a), [In(2Ac4mClPh)2]NO3·EtOH·H2O (2a) and [In(2Ac4pClPh)2]·NO3 (3a) were determined. The cytotoxic effects of the thiosemicarbazone ligands and of complexes (1–4) were evaluated against HL-60, Jurkat and THP-1 leukemia cells and against MCF-7, MDA-MB-231 and HCT-116 solid tumor cells, as well as against mammalian healthy Vero cells. Upon coordination to indium(III) cytotoxicity increased in several cases. In addition, complex (1) was active in sub-micromolar doses against all tested cell lineages, with selectivity indexes (SI = IC50 Vero/IC50 tumor cell) ranging from 3 (against THP-1 cells) to 144 (against HCT-116 cells).

[Cu(HL)2Cl2] complexes (1–6) were prepared with trans-4-stilbenecarboxaldehyde-para-tolyl-hydrazone HStpT (HL1), trans-4-stilbenecarboxaldehyde-para-chloro-phenylhydrazone HStpClPh (HL2), trans-4-stilbenecarboxaldehyde-para-hydroxy-phenylhydrazone HStpOHPh (HL3), trans-4-stilbenecarboxaldehyde-para-nitro-phenylhydrazone HStpNO2Ph (HL4), trans-4-stilbenecarboxaldehyde-acetylhydrazone HStAc (HL5), and trans-4-stilbenecarboxaldehyde-benzoylhydrazone HStBz (HL6). Infrared spectra suggested that the hydrazones act as bidentate ligands which bind to the copper(II) center through the Nimine-O chelating system. EPR spectra of complexes (1–6) were recorded at room temperature for powder samples and at 77 K for DMSO solution. The EPR parameters were compatible with the presence of copper(II). Since the spectroscopic data for complexes (1–6) did not allow the unambiguous determination of the exact geometry of the complexes in the solid state or in solution, theoretical studies were carried out considering five possible isomers, in order to get information on the predominant species. However, although one of the isomers revealed to be the most thermodynamically favorable, free energy differences were not larger than 3 kcal·mol−1. Hence, differences in lattice energy or packing forces could influence the geometry adopted in the solid. The thermodynamic analysis of the five isomers indicated that all of them are in equilibrium in solution. EPR studies suggested that complexes (1–6) interact with bovine (BSA) and human (HSA) serum albumin, with displacement of the hydrazone ligands and coordination of copper(II) to site 1, together with formation of hydrazone-cysteine mixed-ligand copper(II) complexes at site 2 of the albumins.

The aim of the present work was to investigate the rheological properties of different iron oxides (Fe 3 O 4 , NiFe 2 O 4 , ZnFe 2 O 4 and Ni 0.5 Zn 0.5 Fe 2 O 4 ) aqueous suspensions. The oxides were produced through mixing the respective metallic sulfates within a closed isothermal reactor at 100 °C and at pH ≈12, in an oxidant environment (provided by H 2 O 2 0.63% w/v). The reactor was coupled with an adequate real-time data (RTD) acquisition system enabling measurement of temperature, pH and pressure. Obtained RTD data showed that once the isothermal conditions are reached, the pressure slowly decreases over time, which is a result of O 2 consumption through oxidation of Fe 2+ to Fe 3+ . To characterize the suspensions as a function of temperature and shear rate, the steady rheology was used. The results revealed that the effect of temperature on viscosity of all suspensions was insignificant while steady rheology showed pseudoplastic behavior for all ferrites. The magnitude of viscosity and pseudoplasticity turned out to be in agreement with the hydrodynamic diameters of particles complying with the order: NiFe 2 O 4 >Fe 3 O 4 >Ni 0.5 Zn 0.5 Fe 2 O 4 >ZnFe 2 O 4 . Finally, the rheological behavior of suspensions was attributed to the concentration of OH groups on the surface of particles and this hypothesis was effectively supported by DRX, FTIR and TGA/DTA measurements.

In(III) complexes [In(2Ac4oClPh)2]NO3 (1) and [In(2Ac4pFPh)2]NO3·1.5H2O (2) were obtained with N(4)-ortho-chlorophenyl-2-acetylpyridine thiosemicarbazone (H2Ac4oClPh) and N(4)-para-fluorophenyl-2-acetylpyridine thiosemicarbazone (H2Ac4pFPh). Neutron activation of complexes (1) and (2), and of previously prepared [In(2Ac4oClPh)Cl2(MeOH)] (3) and [In(2Ac4pFPh)Cl2(MeOH)] (4) resulted in the formation of 114mIn/115mIn analogues (*1–*4). The cytotoxic activities of the compounds under study were investigated on MCF-7 breast cancer cells as well as against non-malignant MRC-5 fibroblast cells. Upon coordination to In(III) the cytotoxicity against MCF-7 cells significantly increased in complexes (1–4), suggesting that complexation was a good strategy to improve the cytotoxic effect. While both non-radioactive and radioactive In(III) salts were inactive against MCF-7 cells, the radioactive complexes (*1–*4) proved to be 102 to 104 times more potent than the non-radioactive analogues (1–4). For the non-radioactive In(III) complexes (1–4) the selectivity indexes (SI), defined as IC50 MRC-5/IC50 MCF-7, were SI = 0.07–0.36, while high values of SI were found for the radioactive In(III) analogues (*1–*4), SI = 46–4716, indicating that irradiation represented an interesting strategy for increasing the selectivity. Since cytotoxicity was evaluated following 48 h of treatment and 72 h after neutron activation, the observed cytotoxic effects were attributed mainly to 114mIn, the contribution of the 115mIn (t1/2 = 4.5 h) isomer being considered irrelevant. Complexes (*1–*4) induced higher levels of intracellular ROS in MCF-7 cells in comparison to the parent compounds. The results suggest that 114mIn complexes with thiosemicarbazones might show potential for application as radiopharmaceuticals for the treatment of breast cancer.

The aim of this work was to synthesize and characterize the inclusion compounds formed by the complexation of β-cyclodextrin (βCD) with insecticides from the class of benzoylphenylureas (BPUs), named novaluron (NOV) and diflubenzuron (DIF), beyond evaluate their larvicidal activity against Aedes aegypti larvae. Solid state characterization by FTIR showed changes in the main peaks of BPUs and βCD, suggesting the formation of inclusion compounds in solid phase. DTA and TGA thermal analysis showed changes in temperatures of BPUs decomposition as result of molecular interactions. 1H NMR experiments allowed to observe the occurrence of interactions in solution through changes in chemical shifts of BPUs aromatic hydrogens. However, the presence of H–H intermolecular correlations in 2D ROESY was found only for the DIF/βCD complex, suggesting different topology for each complex. Such hypothesis was corroborated by thermodynamic analysis using ITC, which showed different profile of titration curves, beyond endothermic and exothermic interactions for NOV/βCD and DIF/βCD complexes, respectively. DLS titrations of BPUs or BPUs/βCD DMSO solutions in aqueous solution demonstrated that the spontaneously formed hydrophobic nanoprecipitates (HNPs) have different profile of sizes depending on the BPU/βCD system, corroborating also with the hypothesis about the existence of different topologies for each complex. Finally, the HNPs of inclusion compounds showed to be more efficient than free BPUs, allowing proposing a new insecticide formulation.

This work is reports the luminescent properties and positronium formation yields of the Eu(dpm)3 and Eu(dpm)3(2-pyr) complexes, where dpm = 2,2,6,6-tetramethyl-3,5-heptanedionato (dipivaloylmethanate) ion and 2-pyr = 2-pyrrodilidone. We present and discuss experimental intensity parameters of 4f-4f transitions in the Eu3+ complexes under UV excitation. Positron annihilation lifetime spectroscopy (PALS) and Doppler broadening of annihilation radiation lineshape (DBARL) measurements were also performed. It was observed that the photoluminescent properties and Ps formation yields of the complexes are related to intramolecular processes, such as a ligand-to-metal charge transfer (LMCT). The results, which strongly evidence the participation of molecular excited states in the positronium formation, were then discussed in terms of the recently proposed Ps formation mechanism, named cybotactic correlated system kinetic mechanism (CCSKM).This work is reports the luminescent properties and positronium formation yields of the Eu(dpm)3 and Eu(dpm)3(2-pyr) complexes, where dpm = 2,2,6,6-tetramethyl-3,5-heptanedionato (dipivaloylmethanate) ion and 2-pyr = 2-pyrrodilidone. We present and discuss experimental intensity parameters of 4f-4f transitions in the Eu3+ complexes under UV excitation. Positron annihilation lifetime spectroscopy (PALS) and Doppler broadening of annihilation radiation lineshape (DBARL) measurements were also performed. It was observed that the photoluminescent properties and Ps formation yields of the complexes are related to intramolecular processes, such as a ligand-to-metal charge transfer (LMCT). The results, which strongly evidence the participation of molecular excited states in the positronium formation, were then discussed in terms of the recently proposed Ps formation mechanism, named cybotactic correlated system kinetic mechanism (CCSKM).

Complexes [Bi(2AcPh)Cl2]·0.5H2O (1), [Bi(2AcpClPh)Cl2] (2), [Bi(2AcpNO2Ph)Cl2] (3), [Bi(2AcpOHPh)Cl2]·2H2O (4), [Bi(H2BzPh)Cl3]·2H2O (5), [Bi(H2BzpClPh)Cl3] (6), [Bi(2BzpNO2Ph)Cl2]·2H2O (7) and [Bi(H2BzpOHPh)Cl3]·2H2O (8) were obtained with 2-acetylpyridine phenylhydrazone (H2AcPh), its -para-chloro-phenyl- (H2AcpClPh), -para-nitro-phenyl (H2AcpNO2Ph) and -para-hydroxy-phenyl (H2AcpOHPh) derivatives, as well as with the 2-benzoylpyridine phenylhydrazone analogues (H2BzPh, H2BzpClPh, H2BzpNO2Ph, H2BzpOHPh). Upon coordination to bismuth(III) antibacterial activity against Gram-positive and Gram-negative bacterial strains significantly improved except for complex (4). The cytotoxic effects of the compounds under study were evaluated on HL-60, Jurkat and THP-1 leukemia, and on MCF-7 and HCT-116 solid tumor cells, as well as on non-malignant Vero cells. In general, 2-acetylpyridine-derived hydrazones proved to be more potent and more selective as cytotoxic agents than the corresponding 2-benzoylpyridine-derived counterparts. Exposure of HCT-116 cells to H2AcpClPh, H2AcpNO2Ph and complex (3) led to 99% decrease of the clonogenic survival. The IC50 values of these compounds were three-fold smaller when cells were cultured in soft-agar (3D) than when cells were cultured in monolayer (2D), suggesting that they constitute interesting scaffolds, which should be considered in further studies aiming to develop new drug candidates for the treatment of colon cancer.

In this work, we have studied the rheological properties of nickel–zinc and nickel–zinc-β-cyclodextrin (Fe–Ni/Zn and Fe–Ni/Zn/βCD) ferrite suspensions as a function of temperature, solids content, shear rate and NaOH/HNO 3 concentration. The goal was to investigate the conditions where the particle size and viscosity are both lower. In both suspensions, temperature had insignificant impact on viscosity, suggesting no destructive effect on the particles. The Fe–Ni/Zn/βCD suspension exhibited lower viscosity, Newtonian profile and lower dependence of viscosity upon the solids content in comparison with Fe–Ni/Zn, which was pseudoplastic and thixotropic. These differences were ascribed to the lower particle size caused by incorporation of βCD. Considering both ferrites, HNO 3 was more efficient in reducing the particles size and viscosity than NaOH, which affected only the Fe–Ni/Zn. This behavior was rationalized in terms of chemical equilibrium of FeOOH at the surface of particles, which was supported by structural characterization as well as elementary analysis.

Honey is a natural product produced by honey bees whose composition depends on factors such as climate, soil and floral source. It is one of the foods naturally produced, with a characteristic taste and considerable nutritional value. Due to the worldwide demand for large-scale production and seasonality, adulteration has become increasingly frequent. Minas Gerais is the fourth largest Brazilian state producer of honey. Considering that there are few studies on the characterization of honeys in this state and none related to its mesoregions, the objective of this study was to evaluate the physical-chemical, electrical and rheological characteristics of 48 honeys collected in 6 mesoregions of Minas Gerais, corresponding to 75% of its production area. The present study focused on characterization, investigation of the possibility of adulteration and the influence of blossom and regions on the physical-chemical, rheological and electrical properties. Statistical characterization using principal component analysis and clustering were also used. The results suggested that the samples were compatible with the identity and quality standards recommended by Brazilian legislation. Furthermore, the results from rheological analysis and impedance spectroscopy showed that there was a profile specific for each type of blossom. The use of statistical methods on physical-chemical results was a useful tool to characterize different types of honey based on the variables of each group in relation to the similarity between the samples.

In the present work, hydrophobic nanoprecipitates (HNPs) of inclusion complexes formed between β-cyclodextrin (βCD) and the avermectins (AVMs) named eprinomectin (EPRI) and ivermectin (IVER) were synthesized and characterized, and their larvicidal activity against Aedes aegypti and human safety against fibroblasts were evaluated. Initially, thermogravimetric analysis/differential thermal analysis data revealed that inclusion increased the thermal stability of AVMs in the presence of βCD. Nuclear magnetic resonance experiments and density functional theory calculations pointed out the inclusion of the benzofuran ring of the two AVMs in the βCD cavity. Isothermal titration calorimetry experiments allowed identification of different binding constants for EPRI/βCD ( Kb = 1060) and βCD/IVER ( Kb = 1700) systems, despite the structural similarity. Dynamic light scattering titrations of AVMs' dimethyl sulfoxide solution in βCD aqueous solution demonstrated that the formed HNPs have lower sizes in the presence of βCD. Finally, the inclusion of EPRI in βCD increased its larval toxicity and reduced its human cytotoxicity, while for IVER/βCD no beneficial effect was observed upon inclusion. These results were rationalized in terms of structural differences between the two molecules. Finally, the EPRI/βCD complex has great potential as an insecticide against A. aegypti larvae with high human safety.

Antimony(III) [Sb(L)Cl2] complexes were obtained with 2-acetylpyridine-phenylhydrazone (H2AcPh), 2-acetylpyridine-para-chloro-phenylhydrazone (H2AcpClPh), 2-acetylpyridine-para-nitro-phenylhydrazone (H2AcpNO2Ph) and 2-acetylpyridine-para-hydroxy-phenylhydrazone (H2AcpOHPh) along with the 2-benzoylpyridine-phenylhydrazone analogs H2BzPh, H2BzpClPh, H2BzpNO2Ph, H2BzpOHPh (HL). [Sb(2BzpClPh)Cl2], complex (6), (IC50 = 4.91 ± 1.20 μmol L−1) was as active as nystatin (IC50 = 4.44 ± 0.76 μmol L−1) and twofold more active than H2BzpClPh (IC50 = 10.05 ± 0.67 μmol L−1) against Candida dubliniensis. While H2BzpClPh proved to be inactive against Candida glabrata, 6 (IC50 = 10.11 ± 0.64 μmol L−1) was more active than miconazole nitrate (IC50 = 19.50 ± 4.53 μmol L−1). Similarly, H2BzpNO2Ph revealed to be inactive against Candida lusitaniae whereas complex [Sb(2BzpNO2Ph)Cl2] (7) (IC50 = 8.54 ± 2.21 μmol L−1) proved to be as active as nystatin (IC50 = 5.31 ± 0.84 μmol L−1).

O presente trabalho teve como objetivo avaliar o comportamento termico/reologico de tres diferentes composicoes fitoterapicas a base de mel e extratos naturais (denominadas amostras I, II e III), comercializadas na regiao de Governador Valadares – MG. Os espectros de infravermelho dos xaropes apresentaram grandes similaridades entre se a amostras puras de mel, sugerindo qualitativamente composicao quimica semelhante. Do ponto de vista fisico-quimico, as amostras I e II apresentaram comportamentos bem similares, com valores aproximados de massa seca, pH, brix, indice de refracao e tendencia de ionizacao. As amostras I e II apresentaram comportamento quase newtoniano para um ciclo ascendente-descendente de cisalhamento. A amostra III, de maior massa seca, foi a que apresentou maiores valores de viscosidade aparente alem de pseudoplasticidade e histerese reologica, os quais foram atribuidos a presenca de estrutura tridimensional do liquido. Quando diluidas em agua, apesar da brusca queda da viscosidade, as tres amostras assumiram comportamento dilatante, devido a espontânea formacao de nanoestruturas ionicas deformaveis, cujo tamanho se reduz com o aumento de temperatura.

2-Acetylpyridine acetylhydrazone (H2AcMe), 2-benzoylpyridine acetylhydrazone (H2BzMe) and complexes [Cu(H2AcMe)Cl2] (1) and [Cu(H2BzMe)Cl2] (2) were assayed for their cytotoxicity against wild type p53 U87 and mutant p53 T98 glioma cells, and against MRC-5 fibroblast cells. Compounds 1 and 2 proved to be more active than the corresponding hydrazones against U87, but not against T98 cells. Compound 1 induced higher levels of ROS than H2AcMe in both glioma cell lines. H2AcMe and 1 induced lower levels of ROS in MRC5 than in U87 cells. Compound 2 induced lower levels of ROS in MRC5 than in T98 cells. The cytotoxic effect of 1 in U87 cells could be related to its ability to provoke the release of ROS, suggesting that the cytotoxicity of 1 might be somehow p53 dependent.

One of the hallmarks of Alzheimer's disease (AD) in the brain are amyloid-β (Aβ) plaques, and metal ions such as copper(II) and zinc(II) have been shown to play a role in the aggregation and toxicity of the Aβ peptide, the major constituent of these extracellular aggregates. Metal binding agents can promote the disaggregation of Aβ plaques, and have shown promise as AD therapeutics. Herein, we describe the syntheses and characterization of an acetohydrazone (8-H 2 QH), a thiosemicarbazone (8-H 2 QT), and a semicarbazone (8-H 2 QS) derived from 8-hydroxyquinoline. The three compounds are shown to be neutral at pH 7.4, and are potent antioxidants as measured by a Trolox Equivalent Antioxidant Capacity (TEAC) assay. The ligands form complexes with Cu II , 8-H 2 QT in a 1:1 metal:ligand ratio, and 8-H 2 QH and 8-H 2 QS in a 1:2 metal:ligand ratio. A preliminary aggregation inhibition assay using the Aβ 1–40 peptide showed that 8-H 2 QS and 8-H 2 QH inhibit peptide aggregation in the presence of Cu II . Native gel electrophoresis/Western blot and TEM images were obtained to give a more detailed picture of the extent and pathways of Aβ aggregation using the more neurotoxic Aβ 1 −42 in the presence and absence of Cu II , 8-H 2 QH, 8-H 2 QS and the drug candidate PBT2. An increase in the formation of oligomeric species is evident in the presence of Cu II . However, in the presence of ligands and Cu II , the results match those for the peptide alone, suggesting that the ligands function by sequestering Cu II and limiting oligomer formation in this assay.

In this work, a contribution to understanding of the formation of metal(II)/losartan hydrophobic nanoprecipitate is reported. A Ni(II)/Los system was prepared and characterized in solid state and in solution. Solubility studies confirmed the formation of hydrophobic precipitate. Obtained spectroscopic data suggest a sort of coordination between tetrazolic ring as well as OH, and a D 4h geometry around the nickel cation. Thermodynamic studies demonstrated that complexation is a stepwise process, with equal enthalpic and entropic contributions for free energy of complexation. DLS and zeta potential titrations indicate the formation of stable nanoparticles of size and charge dependent on the molar ratio. Finally, rheological studies demonstrate a Bingham plastic behavior for Ni(II)/Los suspension.

Complexes [In(2Ac4oClPh)Cl2(MeOH)] (1), [In(2Ac4pFPh)Cl2(MeOH)] (2), [In(2Ac4pClPh)Cl2(MeOH)] (3) and [In(2Ac4pIPh)Cl2(MeOH)] (4) were obtained with N(4)-ortho-chlorophenyl-2-acetylpyridine thiosemicarbazone (H2Ac4oClPh), N(4)-para-fluorophenyl-2-acetylpyridine thiosemicarbazone (H2Ac4pFPh), N(4)-para-chlorophenyl-2-acetylpyridine thiosemicarbazone (H2Ac4pClPh) and N(4)-para-iodophenyl-2-acetylpyridine thiosemicarbazone (H2Ac4pIPh). Theoretical studies suggested that the coordinated methanol molecule can be easily replaced by DMSO used in the preparation of stock solutions, with the formation of [In(L)Cl2(DMSO)] (HL = thiosemicarbazonate ligand), and that the replacement of DMSO by water is unfavorable. However, for all complexes the displacement of one or two chloride ligands by water in aqueous solution is extremely favorable. The cytotoxic activity of the compounds was evaluated against HL-60, Jurkat and THP-1 leukemia and against MDA-MB-231 and HCT-116 solid tumor cell lines, as well as against Vero non-malignant cells. The cytotoxicity and selectivity indexes (SI) increased in several cases for the indium(III) complexes in comparison with the free thiosemicarbazones. The antimicrobial activity of the compounds was investigated against Candida albicans, Candida dubliniensis, Candida lusitaniae and Candida parapsilosis. In many cases complexation resulted in a substantial increase of the antifungal activity. Complexes (1–4) were revealed to be very active against C. lusitaniae and C. dubliniensis. Structure–activity relationship (SAR) studies were carried out to identify the physico-chemical properties that might be involved in the antifungal action, as well as in the cytotoxic effect of the compounds against HL-60 cells. In both cases, correlations between the bioactivity and physico-chemical properties did not appreciably change when the chloride ligands in [In(L)Cl2(DMSO)] were replaced by water molecules, suggesting [In(L)Cl(H2O)(DMSO)]+ or [In(L)(H2O)2(DMSO)]2+ to be the species that interact with the biological media.

Complexes [Bi(HCQ)2(H2O)Cl3] (1), [Pt(CQ)2]·2KCl (2) and [Pt(CQ)2Cl2]·KCl (3) were obtained with 5-chloro-7-iodo-8-hydroxyquinoline, “clioquinol”, HCQ. Upon coordination to bismuth(III) the antimicrobial activity improved. Complex (1) was 70-fold more active than fluconazole against Candida albicans. HCQ proved to be cytotoxic to HL-60 and Jurkat human leukemia cells. Although coordination to bismuth(III) did not result in significant modification of HCQ’s cytotoxic effect, on coordination to platinum(II, IV) cytotoxicity improved against both cell lines. Complexes (2) and (3) were more active than HCQ against HL-60 cells. Complex (2) also revealed to be the most cytotoxic compound against Jurkat cells, being fivefold more active than cisplatin. Although HCQ and 1 did not show a pro-apoptotic effect, 2 and 3 presented moderate pro-apoptotic activity.

Chalcone-derived 3-phenyl-1-pyridin-2-ylprop-2-en-1-one thiosemicarbazone (HPyCTPh) (1), 3-(4-chlorophenyl)-1-pyridin-2-ylprop-2-en-1-one thiosemicarbazone (HPyCT4ClPh) (2), 3-(4-bromophenyl)-1-pyridin-2-ylprop-2-en-1-one thiosemicarbazone (HPyCT4BrPh) (3), and 3-(4-nitrophenyl-1-pyridin-2-ylprop-2-en-1-one thiosemicarbazone (HPyCT4NO2Ph) (4) were obtained as well as their gallium(III) and zinc(II) complexes [Ga(PyCTPh)2]NO3 (Ga1), [Ga(PyCT4ClPh)2]NO3 (Ga2), [Ga(PyCT4BrPh)2]NO3 (Ga3), [Ga(PyCT4NO2Ph)2]NO3 (Ga4), [Zn(PyCTPh)2] (Zn1), [Zn(PyCT4ClPh)2] (Zn2), [Zn(PyCT4BrPh)2] (Zn3), and [Zn(PyCT4NO2Ph)2] (Zn4). The chalcones, thiosemicarbazones, and zinc(II) complexes were not active against Pseudomonas aeruginosa. The thiosemicarbazones proved to be more active than the parent chalcones against Staphylococcus aureus and Candida albicans. Coordination to zinc(II) resulted in activity improvement of most thiosemicarbazones against S. aureus. Coordination to gallium(III) significantly improved the antimicrobia...

Fourteen phthalazine-triones bearing different substituents at C-4 position were synthesized through multicomponent reactions (MCR) by using phthalhydrazide, dimedone and diferent aldehydes as starting materials, p-sulfonic acid calix[4]arene as catalyst and ethyl lactate as solvent under microwave irradiation. Compounds 7–16 were obtained in excellent to moderate yields (94–51%) in only 10 min of reaction using this methodology. The antiproliferative activity against cancer cells was disclosed, for the first time, for synthesized compounds. The capacity of all compounds to inhibit cancer cells growth was dependent on the histological origin of cells. Compound 20 was active against more than one strain. Keywords: Catalysis, Green chemistry, Microwave assisted synthesis, Antiproliferative activity, p-Sulfonic acid calix[4]arene

Complexes [Au(PyCT4BrPh)Cl]Cl (1), [Pt(PyCT4BrPh)Cl]0.5KCl (2), and [Pd(PyCT4BrPh)Cl]KCl (3) were obtained with 3-(4-bromophenyl)-1-pyridin-2-ylprop-2-en-1-one thiosemicarbazone (HPyCT4BrPh). Although complexes (2) and (3) did not exhibit potent cytotoxic activity, HPyCT4BrPh and its gold(III) complex (1) proved to be highly cytotoxic against HL-60 (human promyelocytic leukemia) and THP-1 (human monocytic leukemia) cells, and against MDA-MB 231 and MCF-7 (human breast adenocarcinoma) solid tumor cells. Except for HL-60 cells, upon coordination to gold(III) a 2- to 3-fold increase in the cytotoxic effect was observed. An investigation on the possible biological targets of the gold(III) complex was carried out. Complex (1) but not the free thiosemicarbazone inhibits the enzymatic activity of thioredoxin reductase (TrxR). The affinity of 1 for TrxR suggests metal binding to a selenol residue in the active site of the enzyme. While HPyCT4BrPh was inactive, 1 was able to inhibit topoisomerase IB (Topo IB) activity. Hence, inhibition of TrxR and Topo IB could contribute to the mechanism of cytotoxic action of complex (1).

Complexes [Bi(2Fo4Ph)Cl(2)] (1), [Bi(2Ac4Ph)Cl(2)] (2), [Bi(2Bz4Ph)Cl(2)] (3), [Bi(H(2)Gy3DH)Cl(3)] (4), [Bi(H(2)Gy4Et)(OH)(2)Cl] (5), and [Bi(H(2)Gy4Ph)Cl(3)] (6) were prepared with pyridine-2-carbaldehyde 4-phenylthiosemicarbazone (H2Fo4Ph), 1-(pyridin-2-yl)ethanone 4-phenylthiosemicarbazone (H2Ac4Ph), phenyl(pyridin-2-yl)methanone 4-phenylthiosemicarbazone (H2Bz4Ph), as well as with glyoxaldehyde bis(thiosemicarbazone) (H(2)Gy4DH) and its 4-Et (H(2)Gy4Et) and 4-Ph (H(2)Gy4Ph) derivatives. The complexes exhibited antibacterial activities against Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, and Pseudomonas aeruginosa. Coordination to Bi(III) proved to be an effective strategy to increase the antibacterial activity of the thiosemicarbazones and bis(thiosemicarbazones).

Complexes [Sb(HAcPh)Cl(2)] (1), [Sb(HAcpClPh)Cl(2)] (2), [Sb(HAcpNO(2)Ph)Cl(2)] (3) and [Bi(HAcPh)Cl(2)] (4), [Bi(HAcpClPh)Cl(2)] (5), [Bi(HAcpNO(2)Ph)Cl(2)] (6) were obtained with 2,6-diacetylpyridine bis(benzoylhydrazone) (H(2)AcPh), 2,6-diacetylpyridine bis(para-chlorobenzoylhydrazone) (H(2)AcpClPh), and 2,6-diacetylpyridine bis(para-nitrobenzoylhydrazone) (H(2)AcpNO(2)Ph). The bis(benzoylhydrazones) were inactive as antimicrobial agents against gram-positive and gram-negative bacteria and against Candida albicans but upon coordination to antimony(III) and bismuth(III) antimicrobial activity was demonstrated. The studied compounds were tested for their cytotoxic activities against Jurkat and HL60 (leukemia), MCF-7 (breast tumor), HCT-116 (colorectal carcinoma) and peripheral blood mononuclear (PBMC) cells. All bis(benzoylhydrazones) proved to be poorly cytotoxic. Upon coordination of the bis(benzoylhydrazones) to antimony(III) and bismuth(III) cytotoxicity significantly improved. Complex (5) presented high therapeutic indexes (TI = 11-508) against all cell lineages.

N(4)-Phenyl 2-acetylpyridine thiosemicarbazone (H2Ac4Ph; N-(phenyl)-2-(1-(pyridin-2-yl)ethylidene)hydrazinecarbothioamide) and its N(4)-ortho-, -meta- and -para-fluorophenyl (H2Ac4oFPh, H2Ac4mFPh, H2Ac4pFPh), N(4)-ortho-, -meta- and -para-chlorophenyl (H2Ac4oClPh, H2Ac4mClPh, H2Ac4pClPh), N(4)-ortho-, -meta- and -para-iodophenyl (H2Ac4oIPh, H2Ac4mIPh, H2Ac4pIPh) and N(4)-ortho-, -meta- and -para-nitrophenyl (H2Ac4oNO(2)Ph, H2Ac4mNO(2)Ph, H2Ac4pNO(2)Ph) derivatives were assayed for their cytotoxicity against human malignant breast (MCF-7) and glioma (T98G and U87) cells. The compounds were highly cytotoxic against the three cell lineages (IC(50): MCF-7, 52-0.16 nM; T98G, 140-1.0 nM; U87, 160-1.4 nM). All tested thiosemicarbazones were more cytotoxic than etoposide and did not present any haemolytic activity at up to 10(-5)M. The compounds were able to induce programmed cell death. H2Ac4pClPh partially inhibited tubulin assembly at high concentrations and induced cellular microtubule disorganization.

In the present work N(3)-meta-chlorophenyl-(HAc3mCl, 1) and N(3)-meta-fluorphenyl-(HAc3mF, 2) acetophenone thiosemicarbazone, and N(3)-meta-chlorophenyl-(HBz3mCl, 3) and N(3)-meta-fluorphenyl-(HBz3mF, 4) benzophenone thiosemicarbazone were obtained, as well as their zinc(II) complexes [Zn(Ac3mCl)2] (5), [Zn(Ac3mF)2] (6), [Zn(Bz3mCl)2] (7) and [Zn(Bz3mF)2] (8). Upon re-crystallization in DMSO:acetone conversion of 8 into [Zn(Bz3mF)2]·(DMSO) (8a) occurred. The crystal structures of 2, 5 and 8a were determined.

[(n-Bu)Sn(2Ac4oClPh)Cl2] (1), [(n-Bu)Sn(2Ac4oFPh)Cl2] (2), [(n-Bu)Sn(2Ac4oNO2Ph)Cl2] (3), [(n-Bu)Sn(2Bz4oClPh)Cl2] (4), [(n-Bu)Sn(2Bz4oFPh)Cl2] (5) and [(n-Bu)Sn(2Bz4oNO2Ph)Cl2] (6) were obtained by reacting [(n-Bu)SnCl3] with 2-acetylpyridine-N4-orthochlorophenyl thiosemicarbazone (H2Ac4oClPh), 2-acetylpyridine-N4-orthofluorphenyl thiosemicarbazone (H2Ac4oFPh), 2-acetylpyridine-N4-orthonitrophenyl thiosemicarbazone (H2Ac4oNO2Ph), and with the corresponding 2-benzoylpyridine-derived thiosemicarbazones (H2Bz4oClPh, H2ABz4oFPh and H2Bz4oNO2Ph). The antifungal activity of the studied compounds was evaluated against several Candida species. Upon coordination of H2Bz4oNO2Ph to tin in complex (6) the antifungal activity increased three times against Candida albicans and Candida krusei and six times against Candida glabrata and Candida parapsilosis. The minimum inhibitory concentration (MIC) values of H2Ac4oNO2Ph and its complex (3) against C. albicans, C. parapsilosis and C. glabrata are similar to that of fluconazole. All studied compounds were more active than fluconazole against C. krusei.

Reaction of N(4)-phenyl-2-formylpyridine thiosemicarbazone (H2Fo4Ph), N(4)-phenyl-2-acetylpyridine thiosemicarbazone (H2Ac4Ph) and N(4)-phenyl-2-benzoylpyridine thiosemicarbazone (H2Bz4Ph) with gallium nitrate gave [Ga(H2Fo4Ph)2](NO3)3 (1), [Ga(2Ac4Ph)2]NO3 (2) and [Ga(2Bz4Ph)2]NO3 (3). In all complexes coordination of the thiosemicarbazone via the Npy–N–S chelating system occurs. In 1 the thiosemicarbazone acts as a neutral ligand while in 2 and 3 the ligand is anionic. Upon slow diffusion of 2 in DMSO [Ga(2Ac4Ph)2]NO3·DMSO (2a) was formed. The crystal structure of 2a was determined. Upon coordination the antibacterial activity of both gallium and thiosemicarbazones against Pseudomonas aeruginosa significantly increases.

Reaction of N(4)-p-tolyl-2-formylpyridine thiosemicarbazone (H2Fo4pT), N(4)-p-tolyl-2-acetylpyridine thiosemicarbazone (H2Ac4pT), and N(4)-p-tolyl-2-benzoylpyridine thiosemicarbazone (H2Bz4pT) with ZnCl2 gave [Zn(H2Fo4pT)Cl2] (1), [Zn(H2Ac4pT)Cl2] (2), and [Zn(H2Bz4pT)Cl2] (3). In the first two complexes a tridentate Npy–N–S thiosemicarbazone binds to the zinc while in the latter N–S coordination occurs. Upon coordination the antibacterial activity against Salmonella typhimurium increases in 1 and 3.

2-Benzoylpyridine-methyl hydrazone (HBzMe) has been obtained as well as its copper(II) [Cu(HBzMe)Cl2] (1) and zinc(II) [Zn(HBzMe)Cl2] (2) complexes. Upon re-crystallization in 1 – 9 DMSO:acetone conversion of 1 into dimeric [Cu(BzMe)Cl]2 (1a) occurred. The crystal structures of HBzMe, 1, 1a, and 2 were determined. HBzMe adopts the ZE conformation in the solid. In all complexes the hydrazone adopts the E configuration to attach to the metal through the Npy N2 O chelating system. In 1 and 2 a neutral hydrazone coordinates to the metal center while in 1a deprotonation occurs with coordination of an anionic ligand. 1a presents a dimeric structure, having two copper(II) ions per asymmetric unit. Two chlorides are also present in the copper coordination sphere, which act as bridging ligands and connect the copper centers to each other.

Reaction of 2-acetylpyridine semicarbazone (H2APS), 3-acetylpyridine semicarbazone (H3APS) and 4-acetylpyridine semicarbazone (H4APS) with [VO(acac)2] (acac = acetylacetonate) gave [VO(H2APS)(acac)2] (1), [VO(H3APS)(acac)2] (2) and [VO(4APS)(acac)(H2O)] · 1/2H2O (3). Oxidation of complex 1 in acetonitrile gave [VO2(2APS)] (4). The crystal structures of complexes 1 and 4 have been determined. Complexes 1–3 were able to enhance glucose uptake and to inhibit glycerol release from adipocytes, which indicate their potential to act as insulin-mimics.

Two novel organoantimony(V) and two organobismuth(V) complexes of the type ML2 were synthesized, with L = acetylsalicylic acid (HL1) or 3-acetoxybenzoic acid (HL2) and M = triphenylantimony(V) (M1) or triphenylbismuth(V) (M2). Complexes, [M1(L1)2] (1), [M1(L2)2]∙CHCl3 (2), [M2(L1)2], (3) and [M2(L2)2] (4), were characterized by elemental analysis, IR and NMR. Crystal structures of triphenylantimony(V) dicarboxylate complexes 1 and 2 were determined by single crystal X-ray diffraction. Structural analyses revealed that 1 and 2 adopt five-coordinated extremely distorted trigonal bipyramidal geometries, binding with three phenyl groups in the equatorial position and two deprotonated organic ligands (L) in the axial sites. The metal complexes, their metal salts and ligands were evaluated in vitro for their activities against Leishmania infantum and amazonensis promastigotes and Staphylococcus aureus and Pseudomonas aeruginosa bacteria. Both the metal complexes showed antileishmanial and antibacterial activities but the bismuth complexes were the most active. Intriguingly, complexation of organobismuth(V) salt reduced its activity against Leishmania, but increased it against bacteria. In vitro cytotoxic test of these complexes against murine macrophages showed that antimony(V) complexes were the least toxic. Considering the selectivity indexes, organoantimony(V) complexes emerge as the most promising antileishmanial agents and organobismuth(V) complex 3 as the best antibacterial agent.

New anionic complexes of lanthanide picrates containing 1-ethyl-3-methylimidazolium (EMIm) as countercation have been prepared. The Ln(III) complexes were characterized by complexometric titration, elemental analyses, infrared spectroscopy and molar conductivity. The molecular structures of the (EMIm)2[Ln(Pic)4(H2O)2]Pic complexes, Ln(III)=Sm, Eu, Gd and Tb, and Pic=picrate, were determined by X-ray crystallography. In these structures the picrate anion appears in three forms: as uncoordinated counteranion, as monodentated and bidentate ligand. The coordination polyhedron around the Ln(III) atom can be described as tricapped trigonal prismatic molecular geometry. The theoretical molecular structures of the complexes were also calculated using the Sparkle/PM3 model for Ln(III) complexes, allowing analysis of intramolecular energy transfer processes of the Eu(III) compound. The spectroscopic properties of the 4f(6) intraconfigurational transitions of the Eu(III) complex were then studied experimentally and theoretically. The low value of emission quantum efficiency of (5)D0 emitting level (η) of Eu(III) ion (ca. 10%) is due to the vibrational modes of the water molecule that act as luminescence quenching. In addition, the luminescence decay curves, the experimental intensity parameters (Ωλ), lifetimes (τ), radiative (Arad) and non-radiative (Anrad) decay rates, theoretical quantum yield (q) were also determined and discussed.

New imidazole derived thiosemicarbazones and hydrazones were prepared by condensation of 4(5)-imidazole carboxaldehyde, 4-(1H-imidazole-1-yl)benzaldehyde and 4-(1H-imidazole-1-yl)acetophenone with a thiosemicarbazide or hydrazide. All compounds were characterized by quantitative elemental analysis, IR and NMR techniques. Eight structures were determined by single crystal X-ray diffraction. The antifungal activities of the compounds were evaluated. None of the compounds exhibited significant activity against Aspergillus flavus and Candida albicans, while 4(5)-imidazolecarboxaldehyde thiosemicarbazone (ImT) and 4-(1H-imidazole-1-yl)benzaldehyde thiosemicabazone (4ImBzT) were highly and selectively active against Cladosporium cladosporioides. 4(5)-Imidazolecarboxaldehyde benzoyl hydrazone (4(5)ImPh), 4(5)-imidazolecarboxaldehyde-para-chlorobenzoyl hydrazone (4(5)ImpClPh), 4(5)-imidazolecarboxaldehyde-para-nitrobenzoyl hydrazone (4(5)ImpNO2Ph), 4-(imidazole-1-yl)acetophenone-para-chloro-benzoyl hydrazone (4ImAcpClPh) and 4-(imidazole-1-yl)acetophenone-para-nitro-benzoylhydrazone (4ImAcpNO2Ph) were highly active against Candida glabrata. 4(5)ImpClPh and 4(5)ImpNO2Ph were very effective against C. cladosporioides. In many cases, activity was superior to that of the reference compound nystatin.

Complexes [Au(2Ac4oT)Cl][AuCl2] (1), [Au(Hpy2Ac4mT)Cl2]Cl·H2O (2), [Au(Hpy2Ac4pT)Cl2]Cl (3), [Pt(H2Ac4oT)Cl]Cl (4), [Pt(2Ac4mT)Cl]·H2O (5), [Pt(2Ac4pT)Cl] (6) and [Pt(L)Cl2OH], L = 2Ac4mT (7), 2Ac4oT (8), 2Ac4pT (9) were prepared with N(4)-ortho- (H2Ac4oT), N(4)-meta- (H2Ac4mT) and N(4)-para- (H2Ac4pT) tolyl-2-acetylpyridine thiosemicarbazone. The cytotoxic activities of all compounds were assayed against U-87 and T-98 human malignant glioma cell lines. Upon coordination cytotoxicity improved in 2, 5 and 8. In general, the gold(III) complexes were more cytotoxic than those with platinum(II,IV). Several of these compounds proved to be more active than cisplatin and auranofin used as controls. The gold(III) complexes probably act by inhibiting the activity of thioredoxin reductase enzyme whereas the mode of action of the platinum(II,IV) complexes involves binding to DNA. Cells treated with the studied compounds presented morphological changes such as cell shrinkage and blebs formation, which indicate cell death by apoptosis induction.

Reaction of highly soluble orally active, non-peptide antihypertensive drug losartan with copper(II) leads to the spontaneous formation of a very insoluble 2:1 covalent complex, which self assembles in a hydrophobic supramolecular structure of nanometric dimensions. Thermal analysis showed that Los/Cu(II) complex presents intermediate stability in comparison with its precursors KLos and Cu(OAc)2·H2O. Isothermal titration calorimetry indicated complexation to be a stepwise process, driven by enthalpy and entropy. Zeta potential and DLS measurements showed that it is possible to control the size and charge of nanoprecipitates by adjusting the relative concentration of Los(-) and Cu(II).

N(4)-Phenyl 2-acetylpyridine thiosemicarbazone (H2Ac4Ph; N-(phenyl)-2-(1-(pyridin-2-yl)ethylidene)hydrazinecarbothioamide) and its N(4)-ortho-, -meta- and -para-fluorophenyl (H2Ac4oFPh, H2Ac4mFPh, H2Ac4pFPh), N(4)-ortho-, -meta- and -para-chlorophenyl (H2Ac4oClPh, H2Ac4mClPh, H2Ac4pClPh), N(4)-ortho-, -meta- and -para-iodophenyl (H2Ac4oIPh, H2Ac4mIPh, H2Ac4pIPh) and N(4)-ortho-, -meta- and -para-nitrophenyl (H2Ac4oNO(2)Ph, H2Ac4mNO(2)Ph, H2Ac4pNO(2)Ph) derivatives were assayed for their cytotoxicity against human malignant breast (MCF-7) and glioma (T98G and U87) cells. The compounds were highly cytotoxic against the three cell lineages (IC(50): MCF-7, 52-0.16 nM; T98G, 140-1.0 nM; U87, 160-1.4 nM). All tested thiosemicarbazones were more cytotoxic than etoposide and did not present any haemolytic activity at up to 10(-5)M. The compounds were able to induce programmed cell death. H2Ac4pClPh partially inhibited tubulin assembly at high concentrations and induced cellular microtubule disorganization.

Six new lanthanide complexes of stoichiometric formula (C)(2)[Ln(Pic)(5)]--where (C) is a imidazolium cation coming from the ionic liquids 1-butyl-3-methylimidazolium picrate (BMIm-Pic), 1-butyl-3-ethylimidazolium picrate (BEIm-Pic), and 1,3-dibutylimidazolium picrate (BBIm-Pic), and Ln is Eu(III) or Gd(III) ions--have been prepared and characterized. To the best of our knowledge, these are the first cases of Ln(III) pentakis(picrate) complexes. The crystal structures of (BEIm)(2)[Eu(Pic)(5)] and (BBIm)(2)[Eu(Pic)(5)] compounds were determined by single-crystal X-ray diffraction. The [Eu(Pic)(5)](2-) polyhedra have nine oxygen atoms coordinated to the Eu(III) ion, four oxygen atoms from bidentate picrate, and one oxygen atom from monodentate picrate. The structures of the Eu complexes were also calculated using the sparkle model for lanthanide complexes, allowing an analysis of intramolecular energy transfer processes in the coordination compounds. The photoluminescence properties of the Eu(III) complexes were then studied experimentally and theoretically, leading to a rationalization of their emission quantum yields.

Complexes [Au(H2Ac4DH)Cl]∙MeOH ( 1 ) [Au(H 2 2Ac4Me)Cl]Cl ( 2 ) [Au(H 2 2Ac4Ph)Cl]Cl∙2H 2 O ( 3 ) and [Au(H 2 2Bz4Ph)Cl]Cl ( 4 ) were obtained with 2-acetylpyridine thiosemicarbazone (H2Ac4DH), its N (4)-methyl (H2Ac4Me) and N (4)-phenyl (H2Ac4Ph) derivatives, as well as with N (4)-phenyl 2-benzoylpyridine thiosemicarbazone (H2Bz4Ph). The compounds were cytotoxic to Jurkat (immortalized line of T lymphocyte), HL-60 (acute myeloid leukemia), MCF-7 (human breast adenocarcinoma) and HCT-116 (colorectal carcinoma) tumor cell lines. Jurkat and HL-60 cells were more sensitive than MCF-7 and HCT-116 cells. Upon coordinating to the gold(I) metal centers in complexes ( 2) and ( 4 ), the cytotoxic activity of the H2Ac4Me and H2Bz4Ph ligands increased against the HL-60 and Jurkat tumor cell lines. 2 was more active than auranofin against both leukemia cells. Most of the studied compounds were less toxic than auranofin to peripheral blood mononuclear cells (PBMC). All compounds induced DNA fragmentation in HL-60 and Jurkat cells indicating their pro-apoptotic potential. Complex ( 2 ) strongly inhibited the activity of thioredoxin reductase (TrxR), which suggests inhibition of TrxR to be part of its mechanism of action.

In the present work 2-formylpyridine-para-chloro-phenyl hydrazone (H2FopClPh) and 2-formylpyridine-para-nitro-phenyl hydrazone (H2FopNO2Ph) were obtained, as well as their copper(II) and zinc(II) complexes [Cu(H2FopClPh)Cl2] (1), [Cu(2FopNO2Ph)Cl] (2), [Zn(H2FopClPh)Cl2] (3) and [Zn(H2FopNO2Ph)Cl2] (4). Upon re-crystallization in DMSO:acetone conversion of 2 into [Cu(2FopNO2Ph)Cl(DMSO)] (2a) and of 4 into [Zn(2FopNO2Ph)Cl(DMSO)] (4a) occurred. The crystal structures of 1, 2a, 3 and 4a were determined.

2-Benzoylpyridine-phenylhydrazone (H2BzPh), 2-benzoylpyridine- para -chloro-phenylhydrazone (H2BzpClPh), and 2-benzoylpyridine- para -nitro-phenyl (H2BzpNO 2 Ph) hydrazone were obtained and fully characterized, as well as their zinc(II) complexes [Zn(H2BzPh)Cl 2 ] ( 1 ), [Zn(H2BzClPh)Cl 2 ] ( 2 ) and [Zn(H2BzpNO 2 Ph)Cl 2 ] ( 3 ). During the syntheses of complex 1 a second product crystallized, which was characterized as [Zn(2BzPh) 2 ] ( 1a ). Upon re-crystallization in 1:9 DMSO:acetone conversion of 2 into [Zn(H2BzpClPh)Cl 2 ] · H 2 O ( 2a ) and of 3 into [Zn(2BzpNO 2 Ph)Cl(DMSO)] ( 3a ) occurred. The crystal structures of 1a , 2a and 3a were determined. In 1a the two nearly perpendicular H2BzPh ligands give rise to a distorted octahedral environment around the metal. The 5-fold coordination around the metal is completed with two chloride ions in 2a and with one chloride and one oxygen atom from DMSO in 3a .