981 resultados para 1,3-Benzodioxole
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Purpose: To study the structure-activity relationships of synthetic multifunctional sulfides through evaluation of lipoxygenase and anti-bacterial activities. Methods: S-substituted derivatives of the parent compound 5-(1-(4-chlorophenylsulfonyl) piperidin-3- yl)-1, 3, 4-oxadiazole-2-thiol were synthesized through reaction with different saturated and unsaturated alkyl halides in DMF medium, with NaH catalyst. Spectral characterization of each derivative was carried out with respect to IR, 1H - NMR, 13C - NMR and EI - MS. The lipoxygenase inhibitory and antibacterial activities of the derivatives were determined using standard procedures. Results: Compound 5e exhibited higher lipoxygenase inhibitory potential than the standard (Baicalein®), with % inhibition of 94.71 ± 0.45 and IC50 of 20.72 ± 0.34 μmoles/L. Compound 5b showed significant antibacterial potential against all the bacterial strains with % inhibition ranging from 62.04 ± 2.78, 69.49 ± 0.41, 63.38 ± 1.97 and 59.70 ± 3.70 to 78.32 ± 0.41, while MIC ranged from 8.18 ± 2.00, 10.60 ± 1.83, 10.84 ± 3.00, 9.81 ± 1.86 and 11.73 ± 5.00 μmoles/L for S. typhi, E. coli, P. aeruginosa, B. subtilis and S. aureus, respectively. Compounds 5d, 5e and 5g showed good antibacterial activity against S. typhi and B. subtilis bacterial strains. Conclusion: The results suggest that compound 5e bearing n-pentyl group is a potent lipoxygenase inhibitor, while compound 5b with n-propyl substitution is a strong antibacterial agent. In addition, compounds 5d, 5e and 5g bearing n-butyl, n-pentyl and n-octyl groups, respectively, are good antibacterial agents against S. typhi and B. subtilis.
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Purpose: To synthesize and characterize S-alkylated/aralkylated 2-(1H-indol-3-ylmethyl)-1,3,4- oxadiazole-5-thiol derivatives. Methods: 2-(1H-indol-3-yl)acetic acid (1) was reacted with absolute ethanol and catalytic amount of sulfuric acid to form ethyl 2-(1H-indol-3-yl)acetate (2) which was transformed to 2-(1H-indol-3- yl)acetohydrazide (3) by refluxing with hydrazine hydrate in methanol. Ring closure reaction of 3 with carbon disulfide and ethanolic potassium hydroxide yielded 2-(1H-indol-3-ylmethyl)-1,3,4-oxadiazole-5- thiol (4) which was finally treated with alkyl/aralkyl halides (5a-u) in DMF and NaH to yield Salkylated/ aralkylated 2-(1H-indol-3-ylmethyl)-1,3,4-oxadiazole-5-thiols (6a-u). Structural elucidation was done by IR, 1H-NMR and EI-MS techniques Results: 2-(1H-indol-3-ylmethyl)-1,3,4-oxadiazole-5-thiol (4) was synthesized as the parent molecule and was characterized by IR and the spectrum showed peaks resonating at (cm-1) 2925 (Ar-H), 2250 (S-H ), 1593 (C=N ) and 1527 (Ar C=C ); 1H-NMR spectrum showed signals at δ 11.00 (s, 1H, NH-1ʹ), 7.49 ( br.d, J = 7.6 Hz, 1H, H-4\'), 7.37 (br.d, J = 8.0 Hz, 1H, H-7\'), 7.34 (br.s, 1H, H-2\'), 7.09 (t, J = 7.6 Hz, 1H, H-5\'), 7.00 (t, J = 7.6 Hz, 1H, H-6\') and 4.20 (s, 2H, CH2-10ʹ). EI-MS presented different fragments peaks at m/z 233 (C11H9N3OS)˙+ [M+2]+, 231 (C11H9N3OS)˙+ [M]+, 158 (C10H8NO)+, 156 (C10H8N2)˙+, 130 (C9H8N)+. The derivatives (6a-6u) were prepared and characterized accordingly. Conclusion: S-alkylated/aralkylated 2-(1H-indol-3-ylmethyl)-1,3,4-oxadiazole-5-thiols (6a-u) were successfully synthesized.
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Purpose: To evaluate the antibacterial, enzyme-inhibitory and hemolytic activities of Salkylated/ aralkylated 2-(1H-indol-3-ylmethyl)-1,3,4-oxadiazole-5-thiol derivatives. Methods: Antibacterial activities of the compounds were evaluated using broth dilution method in 96 well plates. Enzyme inhibitory activities assays were investigated against α-glucosidase, butyrylcholinesterase (BchE) and lipoxygenase (LOX) using acarbose, eserine and baicalien as reference standards, respectively. A mixture of enzyme, test compound and the substrate was incubated and variation in absorbance noted before and after incubation. In tests for hemolytic activities, the compounds were incubated with red blood cells and variations in absorbance were used as indices their hemolytic activities. Results: The compounds were potent antibacterial agents. Five of them exhibited very good antibacterial potential similar to ciprofloxacin, and had minimum inhibitory concentrations (MIC) of at least 9.00 ± 4.12 μM against S. aureus, E.coli, and B. subtilis. One of the compounds had strong enzyme inhibitory potential against α-glucosidase, with IC50 of 17.11 ± 0.02 μg/mL which was better than that of standard acarbose (IC50 38.25 ± 0.12 μg/mL). Another compound had 1.5 % hemolytic activity. Conclusion: S-Alkylated/aralkylated 2-(1H-indol-3-ylmethyl)-1,3,4-oxadiazole-5-thiol deviratives with valuable antibacterial, anti-enzymatic and hemolytic activities have been successfully synthesized. These compounds may be useful in the development of pharmaceutical products.
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The use of InGaAs metamorphic buffer layers (MBLs) to facilitate the growth of lattice-mismatched heterostructures constitutes an attractive approach to developing long-wavelength semiconductor lasers on GaAs substrates, since they offer the improved carrier and optical confinement associated with GaAs-based materials. We present a theoretical study of GaAs-based 1.3 and 1.55 μm (Al)InGaAs quantum well (QW) lasers grown on InGaAs MBLs. We demonstrate that optimised 1.3 μm metamorphic devices offer low threshold current densities and high differential gain, which compare favourably with InP-based devices. Overall, our analysis highlights and quantifies the potential of metamorphic QWs for the development of GaAs-based long-wavelength semiconductor lasers, and also provides guidelines for the design of optimised devices.
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The purpose of this study was to find out if preschool teachers use physical concepts included in thecurriculum for grade 1-3 (gravity, center of gravity, equilibrium, balance and friction) with the children in the outdoor environment at the preschool, if preschool teachers believe it is concepts that works to use with children in preschool outdoor environment and if the work could be developed regarding these physical concepts. To conduct the study, observations were done of preschool yards and semi-structured interviewswere conducted with preschool teachers who work in preschool right now. The result shows that it requires little resources to work with these concepts outdoors and teachers are positive to use the concepts but they do not use it to the extent they would like for a variety of reasons. In various ways, the preschool teachers also expresses that it is possible for children to absorb the physical concepts at preschool and it would help to later build a foundation in the form of childrens thinking that science is something fun and exciting that belong in their everyday lives.
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Resultaten av de internationella undersökningarna PISA 2011 och PIRLS 2011 visar att de svenska elevernas resultat inom läsförståelse försämrats. I Skolinspektionen granskning framkommer det att diskussioner och textsamtal har en relativt liten del av undervisningen av läsförståelse i Sverige idag. Tidigare forskning har ringat in fyra metoder som anses effektivast för elevers utveckling av läsförståelse. Textsamtal, diskussioner och reflektioner har avgörande roller inom alla fyra undervisningsmetoder. Syftet med denna studie är att synliggöra hur sex lärare tänker kring, samt konkret arbetar med, undervisningen av läsförståelse, för att se om de fyra metoderna går att återfinna i de sex lärarnas undervisning. Metoderna som används är semistrukturerade intervjuer samt strukturerade observationer. Resultatet av studien visar att den strategiinriktade undervisningen dominerar undervisningen bland de sex lärarna, och att innehållsorienterad undervisning, vilken visats effektivast i forskningen, är ytterst begränsad. Samtidigt beskriver samtliga lärare att samtal och diskussioner bör vara en stor del av undervisningen inom läsförståelse. En slutsats av studien är att synen på undervisningen av läsförståelse varierar mellan de sex lärarna, samt att allt undervisningsmaterial är baserat på läsförståelsestrategier. Dock förekommer knappt diskussioner och samtal i samband med undervisningen av strategier, vilket är en viktig del för att arbetet med strategiinriktad undervisning ska kunna utveckla elevernas läsförståelse på bästa sätt.
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Syftet med denna kvalitativa studie var att undersöka lärares syfte med laborativt arbete i årskurs 1-3 i NO-undervisningen samt vilka svårigheter som lärarna beskriver med det laborativa arbetssättet i NO-undervisningen. Studien har genomförts med hjälp av kvalitativa intervjuer av sex lärare som är verksamma i årskurserna 1-3. Alla tre årskurserna finns representerade i studien. De resultat som framkommit i studien är att lärare har flera olika syftet med det laborativa arbetet i NO-undervisningen. De syften som framkom var att öka förståelsen för naturvetenskapliga fenomen hos eleverna, öka elevernas motivation och intresse för naturvetenskap, erbjuda elever att uppleva naturvetenskap med händerna, erbjuda eleverna en möjlighet att träna på läroplanens mål, erbjuda eleverna en undervisning som utgår från varje elevs förutsättningar. Studiens frågeställningar berör även hur de intervjuade lärarna använder sig av laborativt arbete samt vilka svårigheter som lärarna uppger finnas med arbetssättet. Studien visar då att lärarna främst arbetar laborativt utomhus främst med biologi och att den svårigheten som flest lärare påpekade var avsaknaden av material.
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In this work we reported the synthesis and evaluation of the analgesic, anti-inflammatory, and platelet anti-aggregating properties of new 3-(arylideneamino)-2-methyl-6,7-methylenedioxy-quinazolin-4 (3H)-one derivatives (3a-j), designed as conformationally constrained analogues of analgesic 1,3- benzodioxolyl-N- acylhydrazones (1) previously developed at LASSBio. Target compounds were synthesized in very good yields exploiting abundant Brazilian natural product safrole (2) as starting material. The pharmacological assays lead us to identify compounds LASSBio-1240 (3b) and LASSBio-1272 (3d) as new analgesic prototypes, presenting an antinociceptive pro. le more potent and effective than dipyrone and indomethacin used, respectively, as standards in AcOH-induced abdominal constrictions assay and in the formalin test. These results confirmed the success in the exploitation of conformation restriction strategy for identification of novel cyclic N-acylhydrazone analogues with optimized analgesic profile (C) 2009 Elsevier Ltd. All rights reserved.
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Objectives were to evaluate the role of canonical WNT signaling in development of the preimplantation embryo. Signaling was activated with 2-Amino-4-(3,4-(methylenedioxy)benzylamino)-6-(3-methoxyphenyl)pyrimidine (AMBMP) and inhibited with Dickkopf-related protein 1 (DKK1). Treatment of bovine embryos with AMBMP at day 5 after insemination decreased development to the blastocyst stage at day 7 and reduced numbers of trophectoderm and inner cell mass cells. At high concentrations, AMBMP caused disorganization of the inner cell mass. DKK1 blocked actions of AMBMP but did not affect development in the absence of AMBMP. Examination of gene expression in day 6 morulae by microarray revealed expression of 16 WNT genes and other genes involved in WNT signaling; differences in relative expression were confirmed by PCR for 7 genes. In conclusion, the preimplantation embryo possesses a functional WNT signaling system and activation of the canonical pathway can inhibit embryonic development.
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Os organismos marinhos constituem uma fonte potencial de metabólitos secundários biologicamente ativos. Neste contexto, os micro-organismos isolados de algas marinhas, dentre eles fungos endofíticos, representam alvos para a pesquisa de novas substâncias com potencial farmacológico pronunciado. Substâncias naturais provenientes de espécies de fungos associados às algas marinhas vêm sendo bastante utilizadas em formulações fotoprotetoras devido à ação antioxidante e ao potencial contra a radiação solar. Deste modo, o presente trabalho teve como objetivo a investigação biológica e química dos fungos endofíticos marinhos pertencentes à família Xylariaceae, o Annulohypoxylon stygium, o Cladosporium sp. e o Acremonium implicatum (Hypocreaceae). A princípio, foi realizado um screening para avaliar a absorção de luz ultravioleta na faixa do UVA e UVB pelos extratos obtidos em escala piloto destes fungos endofíticos associados às algas marinhas. O extrato do fungo A. stygium apresentou intensa absorção na região do UV, mostrando-se promissor para a produção de metabólitos secundários com ação fotoprotetora. Além do ensaio proposto, foi realizada a avaliação do potencial antibacteriano e antifúngico da espécie A. stygium. O estudo químico em escala ampliada deste fungo proporcionou o isolamento e identificação de uma substância inédita da classe derivada da 2,5- dicetopiperazina, 3-benzilideno-2-metil-hexahidro-pirrolo [1,2-?] pirazina-1,4-diona (Sf3), e além desta, foram isolados mais quatro metabólitos como, os diasteroisômeros 1-fenil-1,2- propanediol (Sd2) e 1-fenil-1,2-propanediol (Sd3), 1,3-benzodioxole-5-metanol (Sc1), 1,2- propanodiol-1-(1,3-benzodioxol-5-il) (Se1). Ainda foi possível a desreplicação de substâncias via cromatografia gasosa acoplada à espectrometria de massas (CG-EM), entre elas o ácido palmítico, palmitato de metila, ácido metil linoléico, ácido oléico, álcool benzílico e o piperonal. Quanto ao estudo da atividade biológica, não foi observado potencial antibacteriano e antifúngico para os extratos e frações do fungo. Entretanto, notouse um potencial como fotoprotetor in vitro para as frações n-Hexano/AcOEt (2:3) e n- Hexano/AcOEt (1:4) obtidas a partir do extrato do cultivo de 28 dias do fungo A. stygium, extraído com solventes diclorometano/metanol (CH2Cl2/MeOH 2:1) e para a substância (Sf3) isolada do mesmo. Desta forma, o estudo químico e biológico do fungo Annulohypoxylon stygium demonstrou potencial para a produção de metabólitos secundários com atividade fotoprotetora, visto que uma estrutura inédita com esta atividade foi isolada e identificada como produto natural.
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Twelve novel 8-hydroxyquinoline derivatives were synthesized with good yields by performing copper-catalyzed Huisgen 1,3-dipolar cycloaddition (click reaction) between an 8-O-alkylated-quinoline containing a terminal alkyne and various aromatic or protected sugar azides. These compounds were evaluated in vitro for their antiproliferative activity on various cancer cell types. Protected sugar derivative 16 was the most active compound in the series, exhibiting potent antiproliferative activity and high selectivity toward ovarian cancer cells (OVCAR-03, GI50 < 0.25 μg mL(-1)); this derivative was more active than the reference drug doxorubicin (OVCAR-03, GI50 = 0.43 μg mL(-1)). In structure-activity relationship (SAR) studies, the physico-chemical parameters of the compounds were evaluated and docking calculations were performed for the α-glucosidase active site to predict the possible mechanism of action of this series of compounds.
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In the title salt, K(+)center dot C(4)H(7)BF(3)O(-), the K atom is surrounded by six anions making close contacts through seven F [K center dot center dot center dot F = 2.779 (1)-3.048 (1) angstrom] and two O [K center dot center dot center dot O = 2.953 (2) and 3.127 (2) angstrom] atoms in a trivacant fac-vIC-9 icosahedral coordination geometry.
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Em 30 cepas de Bordetella pertussis isoladas de crianças com coqueluche, atendidas no Hospital de Isolamento Emílio Ribas de São Paulo, foram pesquisados os antígenos aglutinantes ''major" 1, 2 e 3. Levando-se em conta a presença combinada dos três antígenos, as provas de soro-aglutinação rápida em lamina revelaram que 25 (83,3%) cepas possuiam os fatores 1, 2 e 3, enquanto que 3 (10,0%) e 2 (6,7%) foram positivas, somente, para 1, 2 e 1, 3, respectivamente. Os resultados foram discutidos, considerando-se a importância deste antígeno no preparo de vacinas.
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The synthesis and biological evaluation of novel 1-aryl-3-[2-, 3- or 4-(thieno[3,2-b]pyridin-7-ylthio)phenyl]ureas 3, 4 and 5 as VEGFR-2 tyrosine kinase inhibitors, are reported. The 1-aryl-3-[3-(thieno[3,2-b]pyridin-7-ylthio)phenyl]ureas 4a-4h, with the arylurea in the meta position to the thioether, showed the lowest IC50 values in enzymatic assays (10-206 nM), the most potent compounds 4d-4h (IC50 10-28 nM) bearing hydrophobic groups (Me, F, CF3 and Cl) in the terminal phenyl ring. A convincing rationalization was achieved for the highest potent compounds 4 as type II VEGFR-2 inhibitors, based on the simultaneous presence of: (1) the thioether linker and (2) the arylurea moiety in the meta position. For compounds 4, significant inhibition of Human Umbilical Vein Endothelial Cells (HUVECs) proliferation (BrdU assay), migration (wound-healing assay) and tube formation were observed at low concentrations. These compounds have also shown to increase apoptosis using the TUNEL assay. Immunostaining for total and phosphorylated (active) VEGFR-2 was performed by Western blotting. The phosphorylation of the receptor was significantly inhibited at 1.0 and 2.5 microM for the most promising compounds. Altogether, these findings point to an antiangiogenic effect in HUVECs.
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Dissertação de mestrado em Química Medicinal