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In this work, three complexes were synthesized from the trivalent europium ion (EuIII), using the picrate anion (pic), and delta-valerolactam (DVL), epsilon-caprolactam (EPK), and oenantholactam (OEN). The synthesized complexes [Eu(pic)3∙(DVL)3], [Eu(pic)3∙(EPK)3], and [Eu(pic)3∙(OEN)3] were studied as luminescent markers for application as security elements in Brazilian banknotes. All complexes showed red color emission with absorption at 397 nm and emission at 614 nm. Qualitative luminescence tests were performed on R$10, R$20, R$50, and R$100 Brazilian banknotes. The complexes were applied on the surface of the banknotes and were exposed to different wavelengths of 254, 312, 365, and 320-400 nm. The chemical profiles of the complexes were identified on the banknotes employing the laser desorption ionization mass spectrometry (LDI (±) MS) technique. Generally, tests were promising, and can thus provide a simple, fast, and easy method to identify the authenticity of questioned documents, with an average cost of R$0.65 per mg.

Made available in DSpace on 2018-12-11T17:36:55Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-06-01. Added 1 bitstream(s) on 2019-10-09T18:33:12Z : No. of bitstreams: 1 S0103-50532018000601256.pdf: 1399196 bytes, checksum: 4adcb58edc86aa2a4ea4357033d86303 (MD5) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) The syntheses, characterization, cytotoxicity against tumor cells and anti-Mycobacterium tuberculosis activity assays of PtII/PPh3/N,N-disubstituted-N’-acylthioureas complexes with general formulae [Pt(PPh3)2(L)]PF6, PPh3 = triphenylphosphine; L = N,N-disubstituted-N’-acylthiourea, are here reported. The complexes were characterized by elemental analysis, molar conductivity, infrared (IR), nuclear magnetic resonance (NMR) (1H, 13C{1H} and 31P{1H}) spectroscopy. The 31P{1H} NMR data are consistent with the presence of two PPh3 ligands cis to each other position, and one N,N-disubstituted-N’-acylthiourea coordinated to the metal through O and S, in a chelate form. The structures of the complexes were determined by X-ray crystallography, forming distorted square-planar structures. The complexes were tested in human cell lines carcinomas and also screened with respect to their anti-Mycobacterium tuberculosis activity (H37RvATCC 27294). It was found that complexes with N,N-disubstituted-N’-acylthiourea containing open and small chains as R2 groups show higher cytotoxic and higher anti-Mycobacterium tuberculosis activity than those containing rings in this position. Laboratorio de Síntesis Orgánica Facultad de Química Universidad de La Habana Instituto de Física de São Carlos Universidade de São Paulo Departamento de Química Universidade Federal de São Carlos Faculdade de Ciências Farmacêuticas Universidade Estadual Paulista (Unesp) Faculdade de Ciências Farmacêuticas Universidade Estadual Paulista (Unesp) CNPq: 2014/10516-7 CNPq: 2014/12566-1 CAPES: 339/2011 CAPES: CSS/CGCI/ 23038009487/2011-25/DRI/CAPES

We herein report the preparation of AgAu nanotubes displaying controlled surface morphologies and optical properties by varying the reaction temperature during the galvanic reaction between Ag nanowires and AuCl4-(aq). As the AgAu nanotubes presented similar sizes and compositions, they enabled us to isolate the influence of surface morphology and optical properties over their catalytic and plasmonic photocatalytic activities towards methylene blue oxidation. At 25 °C, AgAu nanotubes (AgAu 25) presented branched walls and surface plasmon resonance (SPR) band with low intensities in the visible were obtained. However, at 100 °C, the AgAu nanotubes (AgAu 100) presented smooth surfaces and SPR bands that closely matched the emission spectra of a commercial halogen-tungsten lamp. The AgAu 25 nanotubes displayed better catalytic performances in classical heterogeneous catalysis as a result of its branched walls that lead to increased surface areas relative to the smooth nanotubes. Conversely, AgAu 100 nanotubes showed better activities in plasmonic photocatalysis due to its broader and more intense SPR bands. Thus, our results demonstrate the potential of the control over morphological and optical features towards the optimization of distinct catalytic phenomena.

The labdane diterpenes copalic acid, 3β-acetoxy-copalic acid, 3β-hydroxy-copalic acid and ent-agathic acid were isolated from Copaifera langsdorffii oleoresin. These four compounds were submitted to structural modifications by reduction with hydrogen/palladium, esterification with diazomethane, esterification with methanol/sulfuric acid and conversion into sodium salt, furnishing 15 compounds. All compounds were assayed in vitro against Mycobacterium tuberculosis (H37Rv, ATCC 27294). The four compounds displayed minimum inhibitory concentration (MIC) value of 125 μg mL, and were not considered active. A methylated derivative of compound 3β-hydroxy-copalic acid, and a sodium salt of copalic acid displayed MIC values of 25 μg mL (71.7 μM) and 6.25 μg mL (19.2 μM), respectively. The sodium salt of copalic acid stood out by displaying similar activity in comparison with streptomycin (MIC 6.25 μg mL) and a better activity compared to μM value of pyrazinamide (MIC 3.12 μg mL; 25.34 μM). Therefore, the methylated derivative of compound 3β-hydroxy-copalic acid and the sodium salt of copalic acid should be considered for further studies.

A series of 2-hydroxy-3-arylnaphthalene-1,4-diones (3-aryllawsones) were synthesized by Suzuki-Miyaura cross coupling reaction of 3-iodolawsone with arylboronic acids/esters. The hydroxylated resulting products were transformed into their corresponding N,N-diethyl carbamates. The antineoplastic and antileishmanial activities of the compounds were evaluated and compared with lapachol and its carbamate, providing promising results.

Microcapsules of sugarcane bagasse lignin loaded with organic extracts of neem (Azadirachta indica) were prepared and evaluated as potential bioinsecticides. Lignins were extracted and modified by oxidation and acetylation reactions providing different biopolymers. Afterwards, they were characterized through several analytical techniques. The formulations were initially prepared as colloidal suspension of lignin nanoparticles, which were then spray-dried. The products were submitted to quality control protocols using high performance liquid chromatography (HPLC), thermal and photochemical degradation studies, followed by biological assays against Spodoptera frugiperda and Diatraea saccharalis. The formulations showed increases in both thermal and photo stability of approximately 40% compared with control samples. All the formulated microparticles were efficient against the insects evaluated and required a shorter time to achieve 100% mortality than the controls. The use of sugarcane bagasse lignins to prepare microparticles improved the resistance of neem extracts against abiotic factors, retaining the biological activity of this biopesticide.

Este trabalho descreve a imobilização por ligação covalente de uma ferroporfirina, cloreto de 5,10,15,20-tetraquis(pentafluorofenil)porfirinaferro(III) (FeTFPP), sobre nanoesferas de maguemita cobertas com sílica aminofuncionalizada. O material resultante (nomeadoγ-Fe2O3/SiO2-NHFeP) foi caracterizado por espectroscopia no infravermelho por refletância difusa (DRIFTS) e espectroscopia de absorção UV-Vis. A atividade catalítica desta ferroporfirina magnética foi investigada em reações de oxidação de hidrocarbonetos (estireno, (Z)-cicloocteno e R-(+)-limoneno) e de um herbicida (simazina), utilizando-se peróxido de hidrogênio ou ácido metacloroperbenzóico. Os produtos das reações de oxidação de hidrocarbonetos e simazina foram analisados por cromatografia em fase gasosa (GC) e cromatografia líquida de alta resolução (HPLC), respectivamente. Este sistema catalítico provou ser eficiente e seletivo na oxidação dos hidrocarbonetos, levando a altos rendimentos na oxidação do estireno (89%), cicloocteno (71%) e (+)-limoneno (86%). Na oxidação da simazina catalisada pelo γ-Fe2O3/SiO2-NHFeP, obteve-se 100% de seletividade para um produto desalogenado (OEAT), enquanto a mesma reação em meio homogêneo levou à formação de diversos produtos de oxidação. O catalisador pode ser facilmente recuperado pela aplicação de um campo magnético externo e lavado ao final das reações. Nos estudos de reutilização do catalisador para a oxidação do (+)-limoneno, a atividade catalítica foi mantida em 90%, mesmo após 10 reações consecutivas. This work describes the covalent immobilization of an ironporphyrin, 5,10,15,20- tetrakis(pentafluorophenyl)porphyrin iron(III) chloride (FeTFPP), onto maghemite/silica magnetic nanospheres covered with aminofunctionalized silica. The resulting material (γ-Fe2O3/SiO2-NHFeP) was characterized by diffuse reflectance infrared spectroscopy (DRIFTS) and UV-Vis absorption spectroscopy. The catalytic activity of this magnetic ironporphyrin was investigated in the oxidation of hydrocarbons (styrene, (Z)-cyclooctene and R-(+)-limonene) and an herbicide (simazine) by hydrogen peroxide or 3-chloroperoxybenzoic acid. Hydrocarbon and simazine oxidation reaction products were analyzed by gas chromatography (GC) and high performance liquid chromatography (HPLC), respectively. This catalytic system proved to be efficient and selective for hydrocarbon oxidation, leading to high product yields from styrene (89%), cyclooctene (71%) and R-(+)-limonene (86%). Simazine oxidation was attained with 100% selectivity for a dechlorinated product (OEAT), while several oxidation products were obtained for the same catalyst in homogeneous media. The catalyst can be easily recovered through application of an external magnetic field and washed after reaction. Catalyst reuse experiments for R-(+)-limonene oxidation have shown that the catalytic activity is kept at 90% after 10 consecutive reactions.

Countercurrent chromatography (CCC) was employed as a useful, fast and economic alternative to conventional chromatography techniques for the purification of a synthetic pterocarpanquinone, LQB-118. The separation was performed in a two-step CCC with the solvent system hexane-chloroform-methanol-water 2:1.5:5:2 in both steps. Traditional purification of these reaction products by silica gel column chromatography demanded a large amount of solvent and time, besides allowing the irreversible adsorption of the compound in the column. The use of 1H NMR for the calculation of KD of target compound is proposed as an alternative for HPLC measurements.

Two new furanoflavonoids, 5-hydroxy-2’’-isopropenyl-3-methoxyfurane-(2",3":7,8)-flavone and 5-hydroxy-2’’-(1-hydroxy-1-methylethyl)-3-methoxyfurane-(2",3":7,8)-flavone, along with thirteen other known compounds, were isolated from the root barks of Lonchocarpus obtusus (Leguminosae). The structures of all compounds were determined by spectrometric methods such as 1D and 2D NMR (COSY, HSQC and HMBC) and HREISMS beside comparison with spectral data for similar compounds. Dois novos furanoflavonoides, 5-hidróxi-2’’-isopropenil-3-metoxifurano-(2",3":7,8)-flavona e 5-hidróxi-2’’-(1-hidróxi-1-metiletil)-3-metoxifurano-(2",3":7,8)-flavona, juntamente com treze compostos conhecidos, foram isolados das cascas das raízes de Lonchocarpus obtusos (Leguminosae). As estruturas de todos os compostos isolados foram determinadas usando métodos espectrométricos tais como RMN 1D e 2D (COSY, HSQC e HMBC) e EMAR, além da comparação com dados espectrais descritos na literatura para compostos de estruturas semelhantes.

The reaction between iodo and N-methyl-piperazine or thiomorpholine in water, in the presence of KI, led to the formation of stable and easy to handle amine-iodine complexes, as the complex morpholine-iodo previously reported in the literature. However, the complex obtained using N,N-tetrametylethylenediamine proved less stable, while no complex was formed when piperidine was used as base. These results show that the presence of a second heteroatom in the structure of amines is of fundamental importance for the formation and stability of these complexes. In this work we describe, for the first time, the use of complexes morpholine-iodo, N-methyl-piperazine-iodo and thiomorpholine-iodo as iodinating reagents of several substituted phenols, leading to iodinated products in good to excellent yields.

The reactions of crotonaldehyde (8) with thiophenol (2) and benzalacetone (10) with ethane-1,2-dithiol (11) yield Michael addition products. The reactions of thiophenol (2) with (R)-carvone (13) and (S)-perillaldehyde (15) lead to (2S,3R,5S)-5-isopropenyl-2-methyl-3-(phenylthio)cyclohexanone (14) and (1R,2R,4S)-4-isopropenyl-2-(phenylthio)cyclohexanecarbaldehyde (16), respectively. An unambiguous elucidation of the stereochemistry of 14 and 16 by NMR is also presented.

The influence of electrolyte composition (pure sulphuric or perchloric acid and their mixtures) on the kinetics of the oxygen evolution reaction (OER) and the electrochemical ozone production (EOP) on b-PbO2 electrodes was investigated by electrochemical impedance spectroscopy and quasi-stationary polarisation curves. Analysis of the impedance spectra revealed a dependency of the electric double layer capacity and the adsorption pseudocapacitance, due to reaction intermediates, on electrolyte composition. The pseudocapacitance is a function of electrode potential and electrolyte composition, indicating the surface coverage by the reaction intermediates depends on these parameters. Tafel slope data support primary water discharge as rate determining step of the OER and EOP electrode processes. EOP current efficiency data (FEOP) show pure electrolytes lead to maximum O3 production when compared to mixed electrolytes. According to the theoretical analysis of the electrode mechanism, this behaviour is a consequence of the reduction in surface concentration of the active centres leading to EOP caused by anion adsorption.

N-Chloro- and N-bromosaccharins react with electron rich aromatic compounds (anisole, acetanilide, N,N-dimethylaniline) producing halogenated compounds. The reaction with N-bromosaccharin gives para- substituted compounds only, whereas N-chlorosaccharin produces orto and para mixtures (para isomer predominantly, ca. 4-5 : 1). The reactions of the N-halosaccharins with alkenes (cyclohexene, styrene, a-methylstyrene, and 1-hexene) give the corresponding halohydrins. N-Cloro e N-bromo-sacarinas reagem com compostos aromáticos ricos em elétrons (anisol, acetanilida, N,N-dimetilanilina) para fornecer os produtos de halogenação do anel. As reações com a N-bromo-sacarina fornecem somente os produtos com substituição na posição para, enquanto que a utilização de N-cloro-sacarina gera mistura de produtos orto e para, com predominância do isômero para (ca. 4-5 : 1). Já as reações das halo-sacarinas com alquenos (cicloexeno, estireno, a-metilestireno e 1-hexeno) em acetona aquosa fornecem as respectivas haloidrinas.

A systematic investigation of the mechanistic and electrocatalytic properties of the chlorine evolution reaction, ClER, on mixed rutile/spinel oxides of nominal composition Ti/[RuO2(x)+Co3O4(1-x)] was done. Electrodes were prepared using the thermal decomposition procedure (Tcalc. = 470oC; tcalc. = 1h), with x varied between 0 and 1, changed in 0.1 steps. Kinetics were studied recording quasi-stationary current-potential curves and reaction order determined with respect to H+ and Cl-. A constant Tafel slope of about 33 mV was found for the 0 - 80 mol% RuO2 concentration interval, increasing to 40 mV for higher RuO2 contents. Experimental data support the mechanism originally proposed by Erenburg et al. for the ClER. The edge effect exerts an influence on the electronic transfer coefficient values. Analysis of the electrocatalytic activity reveals an increase in the apparent electrocatalytic activity for the mixed oxides.

This work presents the construction of a novel electrochemical sensor for detection of organic analytes, using a glassy carbon electrode (GCE) modified with a chitosan-supported ruthenium film. The ruthenium-chitosan film was obtained starting from the mer-[RuCl3(dppb)(H2O)] complex as a [1,4-bis(diphenylphosphine)butane] (dppb) precursor, and chitosan (QT). The structure of the chitosan-supported ruthenium film on the surface of the glassy carbon electrode was characterized by UV-Vis spectroscopy, electron paramagnetic resonance (EPR), scanning electron microscopy (SEM), atomic force microscopy (AFM), powder X-ray diffraction (XRD) and atomic absorption spectroscopy (AAS) techniques. The glassy carbon electrode was modified with a film formed from the evaporation of 5 µL of a solution composed of 5 mg chitosan-supported ruthenium (RuQT) in 10 mL of 0.1 mol L-1 acetic acid. The modified electrode was tested as a sensor for sildenafil citrate (Viagra® 50 mg) and acetaminophen (Tylenol®) detection. The technique utilized for these analyses was differential pulse voltammetry (DPV) in 0.1 mol L-1 H2SO4 (pH 1.0) and 0.1 mol L-1 CH3COOK (pH 6.5) as supporting electrolyte. All analyses were carried out during a month using the same electrode. The electrode was washed only with water in between the analyses, keeping it in the refrigerator when it was not in use. This electrode was stable during the period utilized showing no degradation and presenting a linear response over the evaluated concentration interval (1.25 × 10-5 to 4.99 × 10-4 mol L-1).

This work presents a simple, fast and low-cost methodology for the simultaneous determination of paracetamol (PC) and ibuprofen (IB) in pharmaceutical formulations by differential pulse voltammetry using a boron-doped diamond (BDD) electrode. A well-defined oxidation peak was observed using the BDD electrode for each analyte (0.85 V for PC and 1.72 V for IB (vs. Ag/AgCl)) in 0.1 mol L-1 H2SO4 solution containing 10% (v/v) of ethanol. Calibration curves for the simultaneous determination of PC and IB showed a linear response for both drugs in a concentration range of 20 to 400 µmol L-1 (r² = 0.999), with a detection limit of 7.1 µmol L-1 for PC and 3.8 µmol L-1 for IB. The addition-recovery studies in samples were about 100% and the results were validated by chromatographic methods. O presente trabalho apresenta uma metodologia simples, rápida e de baixo custo para determinação simultânea de paracetamol (PC) e ibuprofeno (IB) em formulações farmacêuticas por voltametria de pulso diferencial usando eletrodo de diamante dopado com boro (BDD). Os analitos apresentaram picos de oxidação definidos em 0,85 V para o PC e 1,72 V para o IB (vs. Ag/AgCl) sobre o eletrodo de trabalho de BDD em meio de uma solução de H2SO4 0,1 mol L-1 com 10% (v/v) de etanol. As curvas de calibração mostraram uma resposta linear para determinação simultânea dos analitos entre 20 a 400 µmol L-1 (r² = 0,999) e os limites de detecção obtidos pelas regressões foram de 7,1 µmol L-1 e 3,8 µmol L-1 para PC e IB, respectivamente. Os estudos de adição e recuperação nas amostras ficaram próximos de 100% e os resultados foram validados por métodos cromatográficos.

An improved procedure for the "one-pot" preparation of cathecols from methylenedioxy-ring cleavage reaction of safrole derivatives with aluminum chloride is described. In substrates substituted by conjugated electron-withdrawing groups (carboxyaldehyde or nitro groups) the regioselective formation of the easily isolable chloromethyl ether intermediates was observed. From these intermediates the syntheses of mono-O-methylated phenols (3-hydroxy-4-methoxybenzaldehyde, 2-bromo-4-methoxy-5-hydroxybenzaldehyde, 2-nitro-4-methoxy-5-hydroxybenzaldehyde and 2-methoxy-4-(2-oxoprop-1-yl)-5-nitrophenol) were accomplished. Based on these experimental data and semi-empirical (MNDO) molecular orbital calculations, a mechanistic rationale that explains the observed regioselectivities was also proposed. Um procedimento otimizado para a preparação de catecóis através da reação de quebra da ponte metilenodioxílica de derivados do safrol com cloreto de alumínio é descrito. Em substratos com grupos substituintes atraentes de elétrons (carboxaldeído e nitro) observou-se a formação regiosseletiva de éteres clorometílicos facilmente isoláveis. A partir desses intermediários foram sintetizados os fenóis mono O-metilados (3-hidroxi-4-metoxibenzaldeído, 2-bromo-4-metoxi-5-hidroxibenzaldeído, 2-nitro-4-metoxi-5-hidroxibenzaldeído, e 2-metoxi-4-(2-oxoprop-1-il)-5-nitrofenol). Com base nesses dados experimentais e em cálculos semi-empíricos (MNDO) de orbitais moleculares foi proposta uma racionalização mecanística para explicar as regiosseletividades observadas.

Isatins (1H-indole-2,3-dione) are synthetically versatile substrates, where they can be used for the synthesis of a large variety of heterocyclic compounds, such as indoles and quinolines, and as raw material for drug synthesis. Isatins have also been found in mammalian tissue and their function as a modulator of biochemical processes has been the subject of several discussions. The advances in the use of isatins for organic synthesis during the last twenty-five years, as well as a survey of its biological and pharmacological properties are reported in this review and in the accompanying supplementary information. Isatinas (1H-indol-2,3-diona) são compostos de grande versatilidade sintética, podendo ser utilizados na obtenção de diversos sistemas heterociclos, como derivados indólicos e quinolínicos, o que as tornam importantes matérias-primas na síntese de fármacos. Isatinas também têm sido detectadas em tecidos de mamíferos, o que tem despertado o interesse em seu estudo como moduladores em diversos processos bioquímicos. Os avanços na aplicação de isatinas em síntese orgânica, bem como na compreensão de seus efeitos biológicos e farmacológicos nos últimos vinte e cinco anos encontram-se relatados nesta revisão e seus respectivos materiais suplementares.

Cohalogenation of (R)-limonene and (R)-carvomenthene with I2/H2O/Cu(OAc)2·H 2O in aqueous dioxane followed by base treatment produced stereospecifically the corresponding trans-epoxides. Same methodology of cohalogenation applied to related monoterpenic unsaturated alcohols produced pinol derivatives [from (5R)-cis-carveol and (S)-a-terpineol] or iodohydrins [from (S)-perillyl alcohol and (5R)-trans-carveol].

The Heck reaction between E- and Z-enoates and iodobenzene was studied in the presence of Pd(OAc)2. The stereochemistry in resulting adducts was dependent on the enoate geometry (stereospecific reaction). Best yields were obtained from Z-isomers in acetone using Ag2CO3 as base. The main cationic palladium intermediates possibly involved in the catalytic cycle could be intercepted and characterized by electrospray ionization mass spectrometry (ESI-MS). The stereoselectivity observed was rationalized through the classic mechanism of the Heck reaction.

We report the first synthesis of (±)-3,4-dihydroxy-8,9-methylenedioxypterocarpan, a natural isoflavonoid that shows antitumoral activity. The key step involved the Heck reaction between the 7,8-dibenzyloxychromen and the organomercurial derived from sesamol, followed by debenzylation. The Heck adduct was also employed in the synthesis of the corresponding coumestan derivative, using DDQ as oxidant agent.

Tiofenois reagem com nitro olefinas em meio aquoso dando os correspondentes nitro-sulfetos em 58 - 95 % de rendimento. Este processo leva a formacao, predominante, de produtos anti. Para o caso da nitro olefina ciclica 1-nitro-ciclo-hexeno e observada unicamente a formacao de cis-1-nitro-2-(tio-fenil)-ciclo-hexano. Esta metodologia e interessante porque utiliza-se agua como solvente levando a minimizacao do custo, diminuindo os problemas de toxidez e poluicao ambiental