840 research outputs found
Studies on the reaction of morita-baylis-hillman with indole and carbazole derivatives
Fundação para a Ciência e a Tecnologia (FCT)and FEDE
Synthesis of 5H-pyrido[4,3-b]indole by a modification of Pomeranz-Fritsch isoquinoline synthesis.
5H-Pyrido[4,3-b]indole was obtained from 3-formylindole in 16% overall
yield by Jackson and Shannon modification of the Pomeranz-Fristch isoquinoline
synthesis. The final cyclisation occurred but the removal of the tosyl group and
oxidation of the dihydrocompound was not efficient. Changes in the concentration of
the acid catalyst gave 29% as the best yield for the last step. An NMR study of the
cyclisation is described.Fundação para a Ciência e Tecnologia (FCT)
and FEDE
Cebus cf. apella exhibits rapid acquisition of complex stimulus relations and emergent performance by exclusion
A “second generation” matching-to-sample procedure that minimizes past sources of artifacts involves (1) successive discrimination between sample stimuli, (2) stimulus displays ranging from four to 16 comparisons, (3) variable stimulus locations to avoid unwanted stimulus-location control, and (4) high accuracy levels (e.g., 90% correct on a 16-choice task in which chance accuracy is 6%). Examples of behavioral engineering with experienced capuchin monkeys included four-choice matching problems with video images of monkeys with substantially above-chance matching in a single session and 90% matching within six sessions. Exclusion performance was demonstrated by interspersing non-identical sample-comparison pairs within a baseline of a nine-comparison identity-matching-to-sample procedure with pictures as stimuli. The test for exclusion presented the newly “mapped” stimulus in a situation in which exclusion was not possible. Degradation of matching between physically non-identical forms occurred while baseline identity accuracy was sustained at high levels, thus confirming that Cebus cf. apella is capable of exclusion. Additionally, exclusion performance when baseline matching relations involved non-identical stimuli was shown
Novel benzopsoralen analogues : synthesis, biological activity and molecular docking studies
New benzopsoralen analogues were synthesized and their inhibitory effect on the growth of tumourtumour cell lines (MDA MB231 and TCC-SUP) was evaluated. The in vitro antitumour activity of the new benzopsoralen analogues was discussed in terms of structure–activity relationship. Molecular docking studies with human-CYP2A6 enzymes were also carried out with the synthesized compounds to evaluate the potential of these molecules to interact with the haem group of the enzymes. The results demonstrated that the compounds that are able to interact with the iron ion of the haem cofactor and at the same time with active site Asn297 are those that have better anti-proliferative activity.To the Foundation for the Science and Technology (FCT, Portugal) for financial support to the NMR Portuguese network (PTNMR, Bruker Avance III 400-Univ. Minho). FCT and FEDER (European Fund for Regional Development)-COMPETE-QREN-EU for financial support to the Chemistry Research Centre, CQ/UM [PEst-C/QUI/UI0686/2011 (FCOMP-01-0124-FEDER-022716)], to REQUIMTE (PEst-C/EQB/LA0006/2011), to the Centre of Biological Engineering (PEst-OE/EQB/LA0023/2013) and the PhD grant to C.S.F. (SFRH/BD/48636/2008). The authors also acknowledge the Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP, Porto, Portugal) for kindly providing the breast cancer cell lines used in this work
Synthesis of novel psoralen analogues and their in vitro antitumor activity
New tetracyclic benzofurocoumarin (benzopsoralen) analogues were synthesized and their inhibitory effect on the growth of tumor cell lines was evaluated. The human tumor cell lines used were MDA MB231 (breast adenocarcinoma), HeLa (cervix adenocarcinoma) and TCC-SUP (bladder transitional cell carcinoma). The in vitro antitumor activity of the new benzopsoralens was discussed in terms of structure–activity relationship. Molecular docking studies with human-CYP2A6 enzymes were also carried out with the synthesized compounds in order to evaluate the potential of these compounds to interact with the heme group of the enzymes. The results have demonstrated that the linear compounds have the most pronounced activity against tumor cell lines and this might be related to the better accessibility that these compounds have to the active site in relation to the angular ones that have shown in the majority of the cases multiple binding poses in the active site of CYP2A6.To the Foundation for the Science and Technology (FCT, Portugal) for financial support to the NMR portuguese network (PTNMR, Bruker Avance III 400-Univ. Minho). FCT and FEDER (European Fund for Regional Development)-COMPETE-QREN-EU for financial support to the Research Centre, CQ/UM [PEst-C/QUI/UI0686/2011 (FCOMP-01-0124-FEDER-022716)], (Pest-C/EQB/LA0006/2011) and the PhD grant to C.S.F. (SFRH/BD/48636/2008). The authors also acknowledge the Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP, Porto, Portugal) for kindly providing the breast cancer cell line used in this work
Synthesis of novel psoralen analogues derived from 7-hydroxy-4-methylcoumarin
Fundação para a Ciência e a Tecnologia (FCT) FEDER (European Fund for Regional Development)-COMPETE-QREN-EU FCOMP-01-0124-FEDER-022716FEDER (European Fund for Regional Development)-COMPETE-QREN-EU FCOMP-01-0124-FEDER-02271
Synthesis of esters derived from 2,3,4-tri-O-benzyl-alpha-D-methylglucoside
The synthesis of a set of esters obtained from the D-glucose derivative by reaction with several carboxylic acids: benzoic, phenylacetic, acetylsalicylic, 2-(3-bromopropoxy)benzoic acid and 4-(toluene-4-
sulfonylamino)benzoic acid.FCT (Fundação para a Ciência e Tecnologia) and FEDER for financial support. The Bruker Avance
III 400 spectrometer is part of the National NMR network and was purchased under the framework of the National Programme for Scientific Reequipment,
contract REDE/1517/RMN/2005, with funds from POCI 2010 (FEDER) and (FCT). We are also grateful for research grant VZ MSMT-
0021627501, Czech Republic
Synthesis, wash and light fastness of azo dyes derived from N,N-diethylanilines
A series of monoazo dyes was prepared by coupling carbocyclic and heterocyclic diazo components to four compounds of the N, N-dialkylaniline type. The dyes were characterised by spectroscopic methods, elemental analysis or mass spectrometry. Dispersions of the dyes were applied by conventional techniques to polyester and polyamide, or by reactive dyeing to wool and polyamide, when a CO2H group was present. Wash and light fastness ratings of coloured samples are presented.Foram preparados vários corantes do tipo mono-azo por acoplamento de componentes diazo carboxílicos e heterocíclicos a quatro compostos do tipo N,N-dialquilanilinas. Os corantes foram caracterizados por métodos espectroscópicos, análise elementar ou espectrometria de massa. Foram aplicadas dispersões dos corantes a poliéster e poliamida, ou por tingimento reactivo à lã e poliamida, quando o grupo CO2H estava presente. Apresentam-se os resultados da resistência à luz e à lavagem das amostras coradas
Lack of Aquaporin 3 in bovine erythrocyte membranes correlates with low glycerol permeation
NOTICE: this is the author’s version of a work that was accepted for publication in Biochemical and Biophysical Research Communications. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Biochemical and Biophysical Research Communications. May 2011; 408 (3): 477-481.In general, erythrocytes are highly permeable to water, urea and glycerol. However, expression of aquaporin isoforms in erythrocytes appears to be species characteristic. In the present study, human (hRBC) and bovine (bRBC) erythrocytes were chosen for comparative studies due to their significant difference in membrane glycerol permeability.
Osmotic water permeability (Pf) at 23 ºC was (2.89 ± 0.37) × 10-2 and (5.12 ± 0.61) × 10-2 cm s-1 for human and bovine cells respectively, with similar activation energies for water transport. Glycerol permeability (Pgly) for human ((1.37 ± 0.26) × 10-5 cm s-1) differed in three orders of magnitude from bovine erythrocytes ((5.82 ± 0.37) ×10-8 cm s-1) that also showed higher activation energy for glycerol transport. When compared to human, bovine erythrocytes showed a similar expression pattern of AQP1 glycosylated forms on immunoblot analysis, though in slight higher levels, which could be correlated with the 1.5-fold larger Pf found. However, AQP3 expression was not detectable. Immunofluorescence analysis confirmed the absence of AQP3 expression in bovine erythrocyte membranes.
In conclusion, lack of AQP3 in bovine erythrocytes points to the lipid pathway as responsible for glycerol permeation and explains the low glycerol permeability and high Ea for transport observed in ruminants
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