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‣ Structural study of the interaction of vanadate with the ligand 1,2-dimethyl-3-hydroxy-4-pyridinone (Hdmpp) in aqueous solution

Castro, M. M. C. A.; Geraldes, C. F. G. C.; Gameiro, P.; Pereira, E.; Castro, B.; Rangel, M.
Fonte: Universidade de Coimbra Publicador: Universidade de Coimbra
Tipo: Artigo de Revista Científica Formato: aplication/PDF
Português
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76.33872%
The interaction of vanadate with the ligand 1,2-dimethyl-3-hydroxy-4-pyridinone (Hdmpp) was studied in aqueous solution using a combination of multinuclear NMR and EPR spectroscopies, as well as potentiometry and cyclic voltammetry. The different species in solution were identified and characterized, and their pKa values and stability constants determined. The vanadium complexes formed in solution are strongly dependent on media composition (ionic strength, presence of buffer), pH and metal-to-ligand ratio (M:L). Two major species -- V(V)/dmpp and V(V)/(dmpp)2 -- are formed in a 140 mM NaCl solution within the pH range 4.5 to 9.0, when M:L=1:2. In the presence of excess ligand (M:L<=1:5), only the 1:2 complex is present, and at pH<4 paramagnetic species are detected by EPR in solution, thus indicating a reducing capacity of the ligand. Cyclic voltammetry shows that redox processes in solution are not just electron transfer, but are accompanied by chemical reactions. The pKa values and stability constants were determined both by 51V NMR spectroscopy and potentiometry. The present results have a particular interest in the understanding of the aqueous solution chemistry in aerobic conditions of bis(1,2-dimethyl-3-hydroxy-4-pyridinonato) oxovanadium(IV) complex...

‣ Involvement of sensory nerves and TRPV1 receptors in the rat airway inflammatory response to two environment pollutants: diesel exhaust particles (DEP) and 1,2-naphthoquinone (1,2-NQ)

TELES, Aila Mirtes; KUMAGAI, Yoshito; BRAIN, Susan D.; TEIXEIRA, Simone A.; VARRIANO, Ana A.; BARRETO, Maria Alice A. G.; LIMA, Wothan Tavares de; ANTUNES, Edson; MUSCARA, Marcelo N.; COSTA, Soraia K. P.
Fonte: SPRINGER Publicador: SPRINGER
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
76.38796%
The environmental chemical 1,2-naphthoquinone (1,2-NQ) is implicated in the exacerbation of airways diseases induced by exposure to diesel exhaust particles (DEP), which involves a neurogenic-mediated mechanism. Plasma extravasation in trachea, main bronchus and lung was measured as the local (125)I-bovine albumin accumulation. RT-PCR quantification of TRPV1 and tachykinin (NK(1) and NK(2)) receptor gene expression were investigated in main bronchus. Intratracheal injection of DEP (1 and 5 mg/kg) or 1,2-NQ (35 and 100 nmol/kg) caused oedema in trachea and bronchus. 1,2-NQ markedly increased the DEP-induced responses in the rat airways in an additive rather than synergistic manner. This effect that was significantly reduced by L-732,138, an NK(1) receptor antagonist, and in a lesser extent by SR48968, an NK(2) antagonist. Neonatal capsaicin treatment also markedly reduced DEP and 1,2-NQ-induced oedema. Exposure to pollutants increased the TRPV1, NK(1) and NK(2) receptors gene expression in bronchus, an effect was partially suppressed by capsaicin treatment. In conclusion, our results are consistent with the hypothesis that DEP-induced airways oedema is highly influenced by increased ambient levels of 1,2-NQ and takes place by neurogenic mechanisms involving up-regulation of TRPV1 and tachykinin receptors.

‣ ANTI-TRYPANOSOMAL ACTIVITY OF 1,2,3,4,6-PENTA-O-GALLOYL-beta-D-GLUCOSE ISOLATED FROM Plectranthus barbatus Andrews (Lamiaceae)

Santos, Roberta T. dos; Hiramoto, Liliane L.; Lago, Joao Henrique G.; Sartorelli, Patricia; Tempone, Andre G.; Pinto, Erika G.; Lorenzi, Harri
Fonte: SOC BRASILEIRA QUIMICA; SAO PAULO Publicador: SOC BRASILEIRA QUIMICA; SAO PAULO
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
76.350327%
MeOH extract from the leaves of Plectranthus barbatus Andrews (Lamiaceae), showed in vitro anti-trypanosomal activity. The bioassay-guided fractionation resulted in the isolation of a gallic acid derivative, identified as 1,2,3,4,6-penta-O-galloyl-beta-D-glucose (PGG), after thorough NMR and MS spectral analysis. Finally, this compound was tested against trypomastigote forms of T. cruzi and displayed an EC50 value of 67 mu M, at least 6.6-fold more effective than the standard drug benznidazole. This is the first occurrence of PGG in the Plectranthus genus and the first anti-parasitic activity described for PGG in the literature.; FAPESP; CNPq; CAPES; PIBIC/UNIFESP

‣ Immunomodulatory Effects of Palladium(II) Complexes of 1,2,4-Triazole on Murine Peritoneal Macrophages

Bego, Amadeu M.; Frem, Regina C. G.; Netto, Adelino V. G.; Mauro, Antonio E.; Ananias, Sandra R.; Carlos, Iracilda Z.; da Rocha, Michelle C.
Fonte: Soc Brasileira Quimica Publicador: Soc Brasileira Quimica
Tipo: Artigo de Revista Científica Formato: 437-444
Português
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76.515557%
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); The 1,2,4-triazolyl-bridged polynuclear complexes [{PdCl(2)(mu-Htrz)}(n)] (1) and [{PdBr(2)(mu-Htrz)}(n)] (2) have been obtained in this work. Compound 1 is prepared by the displacement of acetonitrile from [PdCl(2)(MeCN)(2)] by 1,2,4-triazole (Htrz). Further addition of potassium bromide to the reaction medium afforded complex 2. The new complexes have been isolated, purified and characterized by means of elemental analysis, IR and UV-visible electronic spectroscopies and thermogravimetric (TG) curves. The experimental data suggested that, in both cases, the coordination of 1,2,4-Htrz takes place through the N(2) and N(4) atoms, bridging the palladium centers. The square-planar coordination polyhedron of palladium(II) is determined by two nitrogen atoms from the triazole ligands, while the other two coordination positions are occupied by the chloro (1) or bromo (2) ligands. TG curves indicated that the nature of the anionic ligand does not affect significantly the thermal stability of 1 and 2. The final products of the thermal decompositions were identified as metallic palladium by X-ray powder diffractometry. Preliminary tests involving the evaluation of the effects of compounds 1...

‣ Involvement of sensory nerves and TRPV1 receptors in the rat airway inflammatory response to two environment pollutants: diesel exhaust particles (DEP) and 1,2-naphthoquinone (1,2-NQ)

TELES, Aila Mirtes; KUMAGAI, Yoshito; BRAIN, Susan D.; TEIXEIRA, Simone A.; VARRIANO, Ana A.; BARRETO, Maria Alice A. G.; LIMA, Wothan Tavares de; ANTUNES, Edson; MUSCARA, Marcelo N.; COSTA, Soraia K. P.
Fonte: SPRINGER Publicador: SPRINGER
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
76.38796%
The environmental chemical 1,2-naphthoquinone (1,2-NQ) is implicated in the exacerbation of airways diseases induced by exposure to diesel exhaust particles (DEP), which involves a neurogenic-mediated mechanism. Plasma extravasation in trachea, main bronchus and lung was measured as the local (125)I-bovine albumin accumulation. RT-PCR quantification of TRPV1 and tachykinin (NK(1) and NK(2)) receptor gene expression were investigated in main bronchus. Intratracheal injection of DEP (1 and 5 mg/kg) or 1,2-NQ (35 and 100 nmol/kg) caused oedema in trachea and bronchus. 1,2-NQ markedly increased the DEP-induced responses in the rat airways in an additive rather than synergistic manner. This effect that was significantly reduced by L-732,138, an NK(1) receptor antagonist, and in a lesser extent by SR48968, an NK(2) antagonist. Neonatal capsaicin treatment also markedly reduced DEP and 1,2-NQ-induced oedema. Exposure to pollutants increased the TRPV1, NK(1) and NK(2) receptors gene expression in bronchus, an effect was partially suppressed by capsaicin treatment. In conclusion, our results are consistent with the hypothesis that DEP-induced airways oedema is highly influenced by increased ambient levels of 1,2-NQ and takes place by neurogenic mechanisms involving up-regulation of TRPV1 and tachykinin receptors.

‣ The use of an oil–absorber–bioscrubber system during biodegradation ofsequentially alternating loadings of 1,2-dichloroethane and fluorobenzene in awaste gas

Koutinasa, Michalis; Baptista, Inês I. R.; Meniconib, Andrea; Peeva, Ludmila G. Ludmila; Mantalaris, Athanasios; Castro, Paula M. L.; Livingston, Andrew G.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em //2007 Português
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This work seeks to improve the robustness of vapour phase bioscrubbing by applying an absorber prior to a bioscrubber during the dynamic treatment of sequentially alternating loads of inhibitory pollutants. Rhizobiales sp. strain F11 and Xanthobacter autotrophicus sp. GJ10, exhibiting specific degradation capabilities for fluorobenzene (FB) and 1,2-dichloroethane (DCE), respectively, were used as a compound-strain model system. The stability of a combined oil–absorber–bioscrubber (OAB) was compared to the stability of a bioscrubber only (BO) system, during sequentially alternating periods (duration 3–6 d) of FB and DCE in the gas feed. The OAB achieved >66% degradation of FB, while in the BO system the FB removal efficiency dropped to 0% upon restoring FB feed after a 3 d FB starvation period. Following 6 d of FB starvation the BO failed to recover within 10 d, while the OAB required only 2 d to recover. In contrast, during the DCE treatment periods the OAB system did not show any advantage over the BO system. Further investigation showed that the F− (a main metabolic product from FB degradation) has a strong inhibitory effect on strain GJ10 even at concentrations below 50mg L−1. In the OAB system the inhibitory effect persisted for longer periods due to the absorber...

‣ Heterociclos 1,2,3-triazólicos: histórico, métodos de preparação, aplicações e atividades farmacológicas

Melo,Júlio O. F.; Donnici,Claudio Luis; Augusti,Rodinei; Ferreira,Vitor F.; Souza,Maria Cecília B. V. de; Ferreira,Maria Lourdes G.; Cunha,Anna C.
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2006 Português
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The 1,2,3-triazole, known since the end of 19th century, is a very widely used heterocyclic system present in many synthetic substances and commercial pharmaceutical compounds. In fact, 1,2,3-triazoles show several applications in many areas especially as medicines against many diseases like cancer, AIDS, Parkinson and Alzheimer. Nowadays there is a large variety of known methods to obtain these heterocyclic compounds comprising mainly three synthetic routes. Nevertheless, there is no article that gives an objective overview of the synthetic methods for obtaining these kinds of azoheterocycles. This paper presents a brief history of this class of compounds, and a synthetic discussion concerning the main synthetic methods for its preparation, such as cyclization through hydrazones, concerted cycloadditon [2+3] and pseudopericyclic cyclization - and some others of restricted application, but also important. Finally, this paper also provides a brief overview on pharmacological applications of some 1,2,3-triazoles.

‣ Anti-trypanosomal activity of 1,2,3,4,6-penta-O-galloyl-β -D-glucose isolated from Plectranthus barbatus Andrews (Lamiaceae)

Santos,Roberta T. dos; Hiramoto,Liliane L.; Lago,João Henrique G.; Sartorelli,Patrícia; Tempone,André G.; Pinto,Erika G.
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2012 Português
Relevância na Pesquisa
76.350327%
MeOH extract from the leaves of Plectranthus barbatus Andrews (Lamiaceae), showed in vitro anti-trypanosomal activity. The bioassay-guided fractionation resulted in the isolation of a gallic acid derivative, identified as 1,2,3,4,6-penta-O-galloyl-β-D-glucose (PGG), after thorough NMR and MS spectral analysis. Finally, this compound was tested against trypomastigote forms of T. cruzi and displayed an EC50 value of 67 µM, at least 6.6-fold more effective than the standard drug benznidazole. This is the first occurrence of PGG in the Plectranthus genus and the first anti-parasitic activity described for PGG in the literature.

‣ Aspectos virológicos e clínico-patológicos da infecção genital aguda e latente pelo herpesvírus bovino tipo 1.2 em bezerras infectadas experimentalmente

Henzel,Andréia; Diel,Diego G.; Arenhart,Sandra; Vogel,Fernanda S. Flores; Weiblen,Rudi; Flores,Eduardo F.
Fonte: Colégio Brasileiro de Patologia Animal - CBPA; Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA) Publicador: Colégio Brasileiro de Patologia Animal - CBPA; Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA)
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2008 Português
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76.30822%
A infecção genital de vacas pelo herpesvírus bovino tipo 1.2 (BoHV-1.2) pode resultar em vulvovaginite e infertilidade temporária. Após a infecção aguda, o BoHV-1 estabelece infecção latente, que pode cursar com episódios periódicos de reativação. O presente trabalho descreve os aspectos virológicos e clínico-patológicos da vulvovaginite aguda e infecção latente resultantes da inoculação de bezerras com uma amostra de BoHV-1.2 isolada de casos de balanopostite em touros. A inoculação do vírus em quatro bezerras pela via genital (10(8.1)TCID50/animal) resultou em replicação viral na mucosa genital e no desenvolvimento de vulvovaginite moderada a severa. Os animais inoculados excretaram o vírus nas secreções genitais até o dia 10 pós-inoculação (p.i.) com título máximo de 10(7.3)TCID50/mL. Foram observados congestão e edema da mucosa vulvovestibular, e formação de pequenas vesículas e pústulas. Durante a progressão clínica, as vesículas e pústulas aumentaram de tamanho e eventualmente se tornaram coalescentes e recobertas por um exsudato fino de coloração amarelada. Estes sinais foram observados a partir do dia 2 p.i. e aumentaram progressivamente de severidade até os dias 5-8 p.i. A administração de dexametasona no dia 55 p.i. resultou em excreção viral nas secreções genitais dos quatro animais por até 10 dias. A reativação da infecção latente foi acompanhada de recrudescência clínica...

‣ Long-term aerobic swimming training by rats reduces the number of aberrant crypt foci in 1,2-dimethylhydrazine-induced colon cancer

Lunz,W.; Peluzio,M.C.G.; Dias,C.M.G.C.; Moreira,A.P.B.; Natali,A.J.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/11/2008 Português
Relevância na Pesquisa
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We determined the effect of long-term aerobic swimming training regimens of different intensities on colonic carcinogenesis in rats. Male Wistar rats (11 weeks old) were given 4 subcutaneous injections (40 mg/kg body weight each) of 1,2-dimethyl-hydrazine (DMH, dissolved in 0.9% NaCl containing 1.5% EDTA, pH 6.5), at 3-day intervals and divided into three exercise groups that swam with 0% body weight (EG1, N = 11), 2% body weight (EG2, N = 11), and 4% body weight of load (EG3, N = 10), 20 min/day, 5 days/week for 35 weeks, and one sedentary control group (CG, N = 10). At sacrifice, the colon was removed and counted for tumors and aberrant crypt foci. Tumor size was measured and intra-abdominal fat was weighed. The mean number of aberrant crypt foci was reduced only for EG2 compared to CG (26.21 ± 2.99 vs 36.40 ± 1.53 crypts; P < 0.05). Tumor incidence was not significantly different among groups (CG: 90%; EG1: 72.7%; EG2: 90%; EG3: 80%). Swimming training did not affect either tumor multiplicity (CG: 2.30 ± 0.58; EG1: 2.09 ± 0.44; EG2: 1.27 ± 0.19; EG3: 1.50 ± 0.48 tumors) or size (CG: 1.78 ± 0.24; EG1: 1.81 ± 0.14; EG2: 1.55 ± 0.21; EG3: 2.17 ± 0.22 cm³). Intra-abdominal fat was not significantly different among groups (CG: 10.54 ± 2.73; EG1: 6.12 ± 1.15; EG2: 7.85 ± 1.24; EG3: 5.11 ± 0.74 g). Aerobic swimming training with 2% body weight of load protected against the DMH-induced preneoplastic colon lesions...

‣ Preparation and reactions of 3-[3-(aryl)-1,2,4-oxadiazol-5-yl]: propionic acids

Srivastava,R.M; Seabra,G.M
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/1997 Português
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76.4138%
The synthesis of title compounds 3a-g, from arylamidoximes 1a-g and succinic anhydride in high yields is described. 1,2,4-Oxadiazoles 3a-f were also obtained by carrying out the reaction in a domestic microwave oven. Preliminary pharmacological evaluations demonstrated that 3b-e possess analgesic properties. Ab initio molecular orbital calculations of the type STO-3G have been performed for compounds 3a, 4a, 5a and 6a.

‣ Immunomodulatory effects of palladium(II) complexes of 1,2,4-triazole on murine peritoneal macrophages

Bego,Amadeu M.; Frem,Regina C. G.; Netto,Adelino V.G.; Mauro,Antonio E.; Ananias,Sandra R.; Carlos,Iracilda Z.; Rocha,Michelle C. da
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2009 Português
Relevância na Pesquisa
76.50065%
The 1,2,4-triazolyl-bridged polynuclear complexes [{PdCl2(µ-Htrz)}n] (1) and [{PdBr2(µ-Htrz)}n] (2) have been obtained in this work. Compound 1 is prepared by the displacement of acetonitrile from [PdCl2(MeCN)2] by 1,2,4-triazole (Htrz). Further addition of potassium bromide to the reaction medium afforded complex 2. The new complexes have been isolated, purified and characterized by means of elemental analysis, IR and UV-visible electronic spectroscopies and thermogravimetric (TG) curves. The experimental data suggested that, in both cases, the coordination of 1,2,4-Htrz takes place through the N(2) and N(4) atoms, bridging the palladium centers. The square-planar coordination polyhedron of palladium(II) is determined by two nitrogen atoms from the triazole ligands, while the other two coordination positions are occupied by the chloro (1) or bromo (2) ligands. TG curves indicated that the nature of the anionic ligand does not affect significantly the thermal stability of 1 and 2. The final products of the thermal decompositions were identified as metallic palladium by X-ray powder diffractometry. Preliminary tests involving the evaluation of the effects of compounds 1, 2 and Htrz on H2O2 and NO production in cultures of peritoneal macrophages from BALB/c mice were carried out in vitro.

‣ Synthesis, urease inhibition, antioxidant and antibacterial studies of some 4-amino-5-aryl-3H-1,2,4-triazole-3-thiones and their 3,6-disubstituted 1,2,4-triazolo[3,4-b]1,3,4-thiadiazole derivatives

Hanif,Muhammad; Saleem,Muhammad; Hussain,Muhammad Tahir; Rama,Nasim Hasan; Zaib,Sumera; Aslam,Muhammad Adil M.; Jones,Peter G.; Iqbal,Jamshed
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/05/2012 Português
Relevância na Pesquisa
76.3171%
A new series of 4-amino-5-aryl-3H-1,2,4-triazole-3-thiones, bearing various methoxybenzyl- and methoxyphenethyl groups, was synthesized by refluxing potassium hydrazinecarbodithioate salts in dilute aqueous solution of hydrazine hydrate. These salts were formed by the reaction of acid hydrazides and carbon disulfide in methanolic potassium hydroxide solution at 0-5 °C. 4-Amino-5-aryl-3H-1,2,4-triazole-3-thiones were condensed with different substituted aromatic acids to yield 3,6-disubstituted-1,2,4-triazolo[3,4-b]1,3,4-thiadiazoles. The structures of the synthesized compounds were characterized by infrared (IR), ¹H and 13C nuclear magnetic resonance (NMR), elemental analysis and mass spectrometric (MS) studies. All the synthesized compounds were screened for their urease inhibition, antioxidant and antibacterial activities. Some compounds showed excellent urease inhibition activity, more than the standard drug. Others exhibited potent antioxidant activity. All the compounds showed significant antibacterial activities as compared to the standard drug.

‣ Synthesis of N-substituted phthalimidoalkyl 1H-1,2,3-triazoles: a molecular diversity combining click chemistry and ultrasound irradiation

Silva,Moara T. da; Oliveira,Ronaldo N. de; Valença,Wagner O.; Barbosa,Fernanda C. G.; Silva,Mauro G. da; Camara,Celso A.
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2012 Português
Relevância na Pesquisa
76.36893%
A series of 1,2,3-triazole derivatives was synthesized from N-phthalimidoalkyl-azides (A1 -A4) and alkynes (a-e) under ultrasound irradiation in the presence of CuI, Et3N and DMF as solvent. The present protocol afforded 18 new 1,2,3-triazoles (1-4) in good-to-excellent yields (67-98%).

‣ Fragmento 1+2 da protrombina em indivíduos submetidos à angiografia coronariana

Lima,Luciana M.; Sousa,Marinez O.; Fernandes,Ana P.; Loures-Vale,Andréia A.; Fonseca Neto,Cirilo P.; Garcia,José C. F.; Saad,Jamil A.; Carvalho,Maria G.
Fonte: Associação Brasileira de Hematologia e Hemoterapia e Terapia Celular Publicador: Associação Brasileira de Hematologia e Hemoterapia e Terapia Celular
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2005 Português
Relevância na Pesquisa
76.265933%
A trombina exerce um papel fundamental na conversão do fibrinogênio em fibrina, no processo de coagulação. O fator X ativado transforma a protrombina em trombina e fragmento 1+2 da protrombina (F1+2). Os níveis plasmáticos de F1+2 refletem a geração de trombina e podem ser usados como um marcador de hipercoagulabilidade in vivo, já que a trombina é uma substância instável e facilmente degradada, que não pode ser medida diretamente no plasma. O presente estudo teve como objetivo determinar os níveis plasmáticos do F1+2 de um grupo de indivíduos submetidos à angiografia coronariana, buscando estabelecer a possível correlação entre este parâmetro e a gravidade da doença arterial coronariana (DAC). Os níveis plasmáticos do F1+2 foram determinados em amostras de sangue de 17 indivíduos com ausência de ateromatose nas coronárias (controles), 12 indivíduos apresentando ateromatose leve/moderada e 28 indivíduos apresentando ateromatose grave, utilizando-se o conjunto diagnóstico Enzignost F1+2 (Behring® Diagnostics GmbH, Marburg, Germany). Não foram encontradas diferenças estatisticamente significativas entre as médias dos três grupos para o parâmetro avaliado. Portanto, as médias obtidas nos três grupos para os níveis plasmáticos de F1+2 não sinalizam para a existência de um estado de hipercoagulabilidade na população estudada. Entretanto...

‣ Membrane Orientation of Gαiβ1γ2 and Gβ1 γ2 Determined via Combined Vibrational Spectroscopic Studies

Yang, Pei; Boughton, Andrew; Homan, Kristoff T.; Tesmer, John J.G.; Chen, Zhan
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
76.709526%
The manner in which the heterotrimeric G protein complexes Gβ1γ2 and Gαiβ1γ2 interact with membranes is likely related to their biological function. We combined complementary measurements from sum frequency generation (SFG) vibrational and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy to determine the possible membrane orientations of Gβ1γ2 and the Gαiβ1γ2 heterotrimer more precisely than could be achieved using SFG alone. The most likely orientations of Gβ1γ2 and the Gαiβ1γ2 heterotrimer were both determined to fall within a similar narrow range of twist and tilt angles, suggesting that Gβ1γ2 may bind to Gαi without a significant change in orientation. This “basal” orientation seems to depend primarily on the geranylgeranylated C-terminus of Gγ2 along with basic residues at the N-terminus of Gαi, and suggests that activated G protein-coupled receptors (GPCRs) must reorient G protein heterotrimers at lipid bilayers to catalyze nucleotide exchange. The innovative methodologies developed in this paper can be widely applied to study the membrane orientation of other proteins in situ.

‣ Synthese von neuartigen alpha-Aminosäuren sowie Analytik elektrochemisch erzeugter, trisubstituierter 1,2,4-Triazole; Synthesis of novel alpha-amino acids as well as analysis of electrochemically generated trisubstituted 1,2,4-triazoles

Probst, Katrin
Fonte: Universidade de Tubinga Publicador: Universidade de Tubinga
Tipo: Dissertação
Português
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76.40579%
Im Rahmen dieser Arbeit wurde eine kombinatorische Festphasensynthese von neuartigen alpha-Aminosäuren entwickelt sowie analytische Untersuchungen von elektrochemisch erzeugten, trisubstituierten 1,2,4-Triazolen durchgeführt. Der erste Teil der Arbeit ist ein Beitrag zur Kombinatorischen Festphasensynthese von neuartigen alpha-Aminosäuren. Hierbei sindalpha-Aminonitrile die zentralen Bausteine für die Strecker-Drei-Komponenten-Reaktion (S-3CR) wie auch für eine Reihe weiterer Synthesen. Nach der Entwicklung der Festphasensynthese vonalpha-Aminonitrilen wurde eine Reihe verschiedeneralpha-Aminonitril-Kollektionen durch Umsetzung von festphasengebundenem Piperazin mit verschiedenen aliphatischen und aromatischen Aldehyden unter Zugabe von Acetoncyanhydrin hergestellt. Zwei verschiedene Linker-Modelle wurden untersucht: Ein Acrylamino-Wang-Harz lieferte durch Abspaltung mit TFA (25 % in CH2Cl2) Propionsäure-Derivate mit einer Rohproduktreinheit von 70 - 97 %. Durch Quarternisierung des Acrylamino-Wang-Harzes mit verschiedenen Alkylbromiden wurde eine N-Alkylierung des Piperazinrings erreicht. Mit Allylbromid wurden Rohproduktreinheiten von 75 - 99 % erreicht. Bei Verwendung eines Urethan-Linkers wurden durch Abspaltung mit TFA (25 % in CH2Cl2) der freie Stickstoff im Piperazin-Ring erhalten. Die Reinheiten der Rohprodukte bewegten sich hier zwischen 73 und 95 % für aromatische Aldehyde. Durch Verseifung der Nitrilfunktion wurden neuartigealpha-Aminosäuren erhalten...

‣ Utilização de parte da região codificadora da glicoproteína b na diferenciação do herpesvírus bovino 1.1, herpesvírus bovino 1.2 e herpesvírus bovino 5

Costa,E.A.; Barbosa-Stancioli,E.F.; Leite,R.C.; Oliveira,G.D.R.; Rocha,M.A.
Fonte: Universidade Federal de Minas Gerais, Escola de Veterinária Publicador: Universidade Federal de Minas Gerais, Escola de Veterinária
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2005 Português
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Utilizou-se uma reação em cadeia de polimerase (PCR) previamente desenvolvida para a amplificação de parte da região única longa 27 (UL27) do genoma de herpesvírus bovino 1.1 (BoHV-1), que codifica a glicoproteína B, buscando a diferenciação entre isolados de BoHV-1.1 e BoHV-5. Os produtos de PCR gerados a partir de isolados de BoHV-1.1 e BoHV-5 mostraram padrão de amplificação diferenciado em seus tamanhos moleculares. Analisando as seqüências de nucleotídeos dos produtos de PCR obtidos de dois isolados de BoHV-5, juntamente com as seqüências dos produtos de PCR obtidos de um isolado de BoHV-1.1 e de três isolados de BoHV-1.2, previamente depositados no GenBank, verificou-se que a diferença observada na amplificação se deve ao número de repetições de G-C presentes no final da região codificadora da gB, particularmente nas seqüências 5'-G(A/T)CC-3'. A análise dessas seqüências-motivo desponta como uma ferramenta auxiliar na diferenciação entre isolados de BoHV-1.1, BoHV-1.2 e BoHV-5.

‣ Synthesis of novel isatin-type 5'-(4-Alkyl/Aryl-1H-1,2,3-triazoles) via 1,3-dipolar cycloaddition reactions

Silva,Bianca N. M.; Silva,Bárbara V.; Silva,Fernando C.; Gonzaga,Daniel T. G.; Ferreira,Vitor F.; Pinto,Angelo C.
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2013 Português
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Isatin and 1H-1,2,3-triazoles are two classes of compounds with great prominence in organic synthesis and medicinal chemistry as they are heterocycle nuclei with a high reactivity allowing to obtain several compounds with important biological properties. Herein, the synthesis of novel 5'-(4-alquil/aril-1H-1,2,3-triazole)-isatin via reaction of 1,3-dipolar cycloaddition catalyzed by acetic acid is reported.

‣ Evaluación de catalizadores mono- y bimetálicos soportados en Al2O3-TiO2 en la hidrodecloración de 1,2-dicloroetano

García M.,C.; Woolfolk,L. G.; Martín,N.; Granados,A.; De los Reyes,J. A.
Fonte: UAM, Unidad Iztapalapa, División de Ciencias Básicas e Ingeniería Publicador: UAM, Unidad Iztapalapa, División de Ciencias Básicas e Ingeniería
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2012 Português
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En este trabajo se evaluó el efecto de cambios en la fase activa (Pd, Pt, Rh y el bimetálico PdPt (relación molar Pd/Pt=4)) en la reacción de hidrodecloración en fase gaseosa de 3,2 dicloroetano. Como soporte se utilizaron el óxido mixto Al2O3-TiO2 con la relación atómica Al/Ti=25 (AT) y Al2O3 (A). Estos se prepararon por el método sol-gel y sus propiedades texturales se obtuvieron por medio de la fisisorción de N2 (Área BET, volumen de poro y diámetro promedio de poro). La fase activa se impregno con 1% en masa de carga metálica total. La reacción se llevó a caito a 523 K y presión atmosférica en un reactor diferencial de lecho fijo. El soporte AT presentó un área superficial de 422 m²/g, ligeramente mayor a la exhibida por el soporte A (374 m²/g). La velocidad de reacción en la hidrodecloración de 1,2-dicloroetano para los catalizadores soportados en AT resultó en el orden siguiente: Pt