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Xanthenedione derivatives, new promising antioxidant and acetylcholinesterase i...
Seca, Ana M. L.; Leal, Stephanie B.; Pinto, Diana C. G. A.; Barreto, Maria do Carmo; Silva, Artur M. S.Natural and synthetic xanthone derivatives are well-known for their ability to act as antioxidants and/or enzyme inhibitors. This paper aims to present a successful synthetic methodology towards xanthenedione derivatives and the study of their aromatization to xanthones. Additionally their ability to reduce Fe(III), to scavenge DPPH radicals and to inhibit AChE was evaluated. The results demonstrated that xanth...
Diálogos de modernidade no Azulejo em Portugal (1949 -1970)
Silva, Artur Manuel Pedro daDissertação apresentada para cumprimento dos requisitos necessários à obtenção do grau de Mestre em História da Arte Contemporânea
Chemical study and biological activity evaluation of two Azorean Macroalgae: Ul...
Silva, Madalena; Vieira, Luís M.; Almeida, Ana Paula; Silva, Artur M. S.; Seca, Ana M. L.; Barreto, Maria do Carmo; Neto, Ana I.; Pedro, MadalenaCopyright: © 2013 Silva M, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credite. ; The green macroalga Ulva rigida C. Agardh (Chlorophyta) and the red macroalga Gelidium microdon Kützing (Rhodophyta), collected from the Azore...
Valuable compounds on conifers, macroalgae and halophyte species
Isca, Vera M. S.; Gouveia, Vera F.; Seca, Ana M. L.; Barreto, Maria do Carmo; Pinto, Diana C. G. A.; Silva, Artur M. S.; Kijjoa, AnakeXXIII Encontro Nacional da Sociedade Portuguesa de Química, Aveiro 12 a 14 de Junho de 2013. ; As part of our on-going investigation on bioactive secondary metabolites, we carried out the phytochemical study of the endemic conifer Juniperus brevifolia and the macroalga Cystoseira abies-marine from Azores Islands, and also of the halophyte Salicornia ramosissima from Aveiro lagoon. This communication gives an o...
Salicornia ramosissima: secondary metabolites and testicular protection induced...
Ferreira, Daniela; Isca, Vera M. S.; Seca, Ana M. L.; Pereira, M. Lourdes; Silva, Helena; Pinto, Diana C. G. A.; Silva, Artur M. S.XXIII Encontro Nacional da Sociedade Portuguesa de Química. Aveiro, 12-14 de Junho 2013. ; The structure and spectroscopic characterization of the isolated compounds from etanol and dichloromethane extracts (PUFA omega3 ethylated, sterol and a rare wax) will be presented and discussed. Concerning the effect of ethanolic extract on mice testicular tissue under carbon tetrachloride exposure, it was clearly demon...
Organic compounds isolated from Juniperus brevifolia bark
Vieira, Amélia; Martins, Marcele; Seca, Ana M. L.; Pinto, Diana C. G. A.; Silva, Artur M. S.10º Encontro Nacional de Química Orgânica e 1º Simpósio Luso-Brasileiro de Química Orgânica, Lisboa, 4-6 Setembro de 2013 ; In continuation of our study on the chemical characterization of endemic plants of the Azores archipelago, we have examined Juniperus brevifolia. Our interest in this plant was stimulated by the wide range of biological activities reported for other species of this genus and/or of their c...
New syntheses of potential biologically active xanthones and benzoxanthones
Rocha, Djenisa H. A.; Leal, Stephanie B.; Seca, Ana M. L.; Pinto, Diana C. G. A.; Silva, Artur M. S.10º Encontro Nacional de Química Orgânica e 1º Simpósio Luso-Brasileiro de Química Orgânica, Lisboa, 4-6 Setembro de 2013. ; The synthesis of xanthones, adequately functionalized for a specific application, is a challenging task. In this presentation, will be disclosed our recent studies with this unique family of compounds, namely the one-pot photoinduced electrocyclisation of (E)-3-styrylflavones 1 and in si...
Six-membered ring systems: with O and/or S atoms
Santos, Clementina M. M.; Silva, Artur M.S.A large variety of publications have emerged in 2012 involving O- and S-6- membered ring systems. The increasing number of reviews and other communica- tions dedicated to natural and synthetic derivatives and their biological significance highlights the importance of these heterocycles. Reviews on natural products involve biosynthesis and isolation of enantiomeric derivatives h12AGE4802i, biosynthesis, isolatio...
Electrochemical characterization of bioactive hydroxyxanthones by cyclic voltam...
Santos, Clementina M.M.; Garcia, Beatriz; Silva, Artur; Santus, René; Morlière, Patrice; Fernandes, EduardaThe present study reports the electrochemical behavior of several phenolic and catecholic-substituted 2,3-diarylxanthones on a glassy carbon electrode, challenged by cyclic voltammetry at different pH values (4.0, 7.4, and 11.0). Higher pH values required lower anodic and cathodic peak voltages. The oxidation of catecholic groups occurred at lower peak potentials in a reversible and pH dependent manner. Anodic ...
Synthesis of 2-{2-[5(4)-aryl-2H-[1,2,3]-triazol-4(5)-yl]vinyl}chromen-4-ones
Albuquerque, Hélio; Santos, Clementina M.M.; Silva, Artur; Cavaleiro, José A.S.Chromones are a family of oxygen-containing heterocyclic compounds that have been shown particular relevant biological activity. In what concerns to 2-methylchromones, their reactivity is well-known and allowed to exploit many different kinds of chemical reactions. The acidic character of the 2-methyl group, due to the low electron density at C-2 caused by carbonyl group enable this class of compounds to underg...
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