950 resultados para inositol 1,4,5 trisphosphate


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Em palestra realizada no dia 04 de julho, o professor Wilson Nobre (membro fundador e pesquisador do Fórum de Inovação da FGV-EAESP), falou sobre Inovação na Cadeia de Valor

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Esta é uma das seis partes da videoaula que integra o conteúdo do especial P22_ON sobre precificação de carbono. Nesta série, a pesquisadora do GVces Inaiê Takaes Santos faz um exercício teórico no qual analisa o custo-benefício da tributação e do sistema de comércio de emissões

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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

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A new reaction mode of 6,7-bis(methylsulfanyl)-1,4-dihydro-1,4-methanonaphthalene-5,8-dione 1 with the hard nucleophiles sodium benzene- or methane-sulfinate and cyanide, in DMSO, at room temperature, leads to the unexpected hydroquinonoid products 3a-c. All the data are in agreement with a mechanistic pathway involving the initial attack of the hard nucleophile onto the hard carbonyl group, followed by a symbiotic re-attack of the oxygen on the incoming group. In the case of soft nucleophiles, reaction on the olefinic carbon of the enedione system is preferential.

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This paper describes a new method for the preparation of sodium 4-[5-(4-hydroxy-3-methoxyphenyl)-3-oxo-penta-1,4-dienyl]-2-methoxy-phenolate, DM-1, and 3-oxo-penta-1,4-dienyl-bis (2-methoxy-phenolate), DM-2. The aim of this work was to evaluate the antitumor effects of DM-1 in adjuvant chemotherapy for breast cancer treatment. Mice bearing mammary adenocarcinomas (Ehrlich ascites tumors) were treated with paclitaxel alone, DM-1 alone, and paclitaxel + DM-1. Tumor samples were used to perform cytological analysis by the Papanicolaou method and apoptosis analysis by annexin V and phosphorylated caspase 3. The paclitaxel + DM-1 group had decreased tumor areas and tumor volumes, and the frequency of metastasis was significantly reduced. This caused a decrease in cachexia, which is usually caused by the tumor. Furthermore, treatment with paclitaxel + DM-1 and DM-1 alone increased the occurrence of apoptosis up to 40% in tumor cells, which is 35% more than in the group treated with paclitaxel alone. This cell death was mainly caused through phosphorylated caspase 3 (11% increase in paclitaxel + DM-1 compared to the paclitaxel group), as confirmed by reduced malignancy criteria in the ascitic fluid. DM-1 emerges as a potential treatment for breast cancer and may act as an adjuvant in chemotherapy, enhancing antitumor drug activity with reduced side effects.

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A very fast, easy and efficient synthesis is described for a novel and biologically important class of 1,4-disubstituted-4-(5-pyrrolidin-2-one)-1,2,3-triazoles by an ultrasound-assisted one-pot, three-step click reaction sequence of 5-[(trimethylsilyl)ethynyl]pyrrolidin-2-one with organic azides mediated by catalytic Cu-I salts.

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The new triazene-porphyrin dye 5-(1-(4-phenyl)-3-(4-nitrophenyl)triazene)-10,15,20-triphenylporphyrin, encompassing a reactive protonated triazene moiety, was prepared starting from meso-tetraphenylporphyrin (H2TPP), first converting it to the 5-(4-nitrophenyl)-10,15,20-triphenylporphyrin, then reducing to the 5-(4-aminophenyl)-10,15,20-tri(phenyl) porphyrin intermediate, and reacting with the diazonium salt of 4-nitroaniline; and characterized by spectroscopic and electrochemical methods. The absorption spectrum of the neutral species resembled the sum of H2TPP and of 1,3-bis(4-nitrophenyl) triazene spectrum, but the deprotonated anionic species showed more delocalized frontier orbitals, behaving as a push-pull system exhibiting triazenide-to-porphyrin charge-transfer transitions.

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Il progetto di tesi specialistica svolto durante questo anno accademico si è suddiviso in due parti: un primo periodo, da settembre 2010 a gennaio 2011, presso il dipartimento di Chimica Organica “A. Mangini” della Facoltà di Chimica Industriale dell’Università di Bologna e un secondo periodo in Spagna, da marzo ad agosto 2011, presso la Unitat de Química Farmacèutica de la Facultat de Farmàcia de la Universitat de Barcelona. Nel primo periodo a Bologna mi sono occupato della sintesi di 4-bromo-pirazoli da utilizzare come precursori di composti eterociclici condensati. Inizialmente è stato sintetizzato un pirazolo 1,3,5-trisostituito tramite cicloaddizione 1,3-dipolare tra un acetilene e una nitril immina generata in situ da un idrazonoil cloruro. Il pirazolo è stato poi bromurato facendo uno screening di diversi agenti bromuranti e condizioni di reazione per ottenere la migliore resa e chemoselettività. Infine è stata studiata la ciclizzazione intramolecolare del prodotto bromurato tramite reazione di cross-coupling catalizzata da metalli di transizione. Nel secondo periodo a Barcellona mi sono occupato della sintesi di dicarbossimmidi tricicliche con struttura a gabbia con il fine di creare alcheni altamente piramidalizzati e di studiarne la dimerizzazione ad un derivato del dodecaedrano. La strategia sintetica è stata impostata utilizzando come reagente di partenza una semplice succinimmide per giungere, dopo numerosi passaggi, al precursore del prodotto triciclico, del quale è stata studiata la ciclizzazione tramite reazione Diels-Alder intramolecolare.

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Oligomere mit konjugierten pi-Elektronensystemen sind für die Materialwissenschaften von großer Bedeutung. Die vielfältigen und umfangreichen Forschungen auf diesem Gebiet gründen im Potenzial dieser Substanzklassen, das im Bereich der Laserfarbstoffe, Leuchtdioden, Photoleiter, optische Schalter oder auch der molekularen Elektronik angesiedelt ist. Zu diesen gehören auch die in dieser Arbeit synthetisierten und untersuchten Phenylenethinylene. Die Herstellung der Oligomere erfolgt nach der Methode von Sonogashira und Hagihara. Dabei wird ein Halogenaren mit einer Alkinkomponente zur Reaktion gebracht. Als Katalysator dient dabei ein Gemisch aus Bis(triphenylphosphin-palladiumdichlorid), Kupfer-(I)-iodid und Triphenylphosphin. Verwendung fanden bei der Synthese zwei Arten von Schutzgruppen. Es handelt sich dabei einerseits um die Trimethylsilyl- und die Triisopropylsilyl-Funktion, die unabhängig voneinander in ein System eingeführt werden und selektiv wieder entfernt werden können. Die zweite Art sind die Halogene Brom und Iod, die aufgrund ihrer Eigenschaft vielmehr als 'dormant group' bezeichnet werden müssen. Eine Ethinylierung führt zunächst zur Substitution des Iod- und anschließend des Bromatoms. Die so erhaltenen Oligomere werden mit verschiedenen spektroskopischen Methoden untersucht. Besonderes Interesse liegt dabei auf der Bestimmung der effektiven Konjugationslänge (EKL). Damit ist es möglich, die Länge des konjugierten Systems zu bestimmen, das für die betreffenden Eigenschaften des entsprechenden Polymers maßgeblich ist. Das nichtlineare optische Verhalten der Oligomere wird mittels der Third-Harmonic-Generation-Methode (THG) gemessen. Die resultierende Größe, die Suszeptibilität 3. Ordnung, gibt Aufschluß über mögliche industrielle Anwendungen.

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The title compound, C(34)H(24)Cl(4)N(4)O(8)S, is a linear penta-cyclic system formed of two substituted benzoxazinyl groups fused to 2-n-butyl-tetra-hydro-thio-phene. The oxazine ring, which is fused to the n-butyl-substituted side of the thio-phene ring, is in a boat conformation. The other fused oxazine ring and the tetra-hydro-thiene ring are each in an envelope conformation. The bridgehead C atom alpha to both the S and N atoms forms the flap of each envelope. This results in a twist of the penta-cyclic system such that the dihedral angle between the terminal dichloro-benzene rings is 82.92 (8)°. In the crystal, inversion-related mol-ecules form a weakly hydrogen-bonded dimer, with two C-H⋯O inter-actions between an H atom on the oxazine ring and an amide O atom. Additionally, C-H⋯O inter-actions occur between an H atom on a screw-related nitro-benzene ring and an O atom on the nitro-benzene ring of one mol-ecule. One of the Cl atoms and the butyl group are disordered over two sets of sites with occupancy ratios of 0.94 (2):0.06 (2) and 0.624 (4):0.376 (4), respectively.

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PhIP carcinogenesis is initiated by N(2)-hydroxylation, mediated by several cytochromes P450, including CYP1A1. However, the role of CYP1A1 in PhIP metabolic activation in vivo is unclear. In this study, Cyp1a1-null and wild-type (WT) mice were used to investigate the potential role of CYP1A1 in PhIP metabolic activation in vivo. PhIP N(2)-hydroxylation was actively catalyzed by lung homogenates of WT mice, at a rate of 14.9 +/- 5.0 pmol/min/g tissue, but < 1 pmol/min/g tissue in stomach and small intestine, and almost undetectable in mammary gland and colon. PhIP N(2)-hydroxylation catalyzed by lung homogenates of Cyp1a1-null mice was approximately 10-fold lower than that of WT mice. In contrast, PhIP N(2)-hydroxylation activity in lung homogenates of Cyp1a2-null versus WT mice was not decreased. Pretreatment with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) increased lung Cyp1a1 mRNA and lung homogenate PhIP N(2)-hydroxylase activity approximately 50-fold in WT mice, where the activity was substantially inhibited (70%) by monoclonal antibodies against CYP1A1. In vivo, 30 min after oral treatment with PhIP, PhIP levels in lung were similar to those in liver. After a single dose of 0.1 mg/kg [(14)C]PhIP, lung PhIP-DNA adduct levels in Cyp1a1-null mice, but not in Cyp1a2-null mice, were significantly lower (P=0.0028) than in WT mice. These results reveal that mouse lung has basal and inducible PhIP N(2)-hydroxylase activity predominantly catalyzed by CYP1A1. Because of the high inducibility of human CYP1A1, especially in cigarette smokers, the role of lung CYP1A1 in PhIP carcinogenesis should be considered.