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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...


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, Madalena

Copyright: © 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, Anake

XXIII 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...

Data: 2013   |   Origem: Biblioteca Digital do IPB

Simultaneous characterization and quantification of phenolic compounds in Thymu...

Pereira, Olívia R.; Peres, António M.; Silva, Artur M.S.; Domingues, M.R.M.; Cardoso, Susana M.

Thymus x citriodorus is a Lamiaceae plant extensively cultivated in Mediterranean region and used for centuries in culinary and in traditional medicine. The present work describes the detailed phenolic composition of T. x citriodorus for the first time, the by means of HPLC-DAD, ESI-MS and MSn and nuclear magnetic resonance (NMR) analyses. The ethanolic extract of T. x citriodorus was analyzed by reversed phase...

Data: 2013   |   Origem: Biblioteca Digital do IPB

Synthesis of new 1,8-dihydroxy-9h-xanthen-9-ones

Leal, Stephanie B.; Seca, Ana M. L.; Pinto, Diana C. G. A.; Silva, Artur M. S.; Cavaleiro, José A. S.

XXVth European Colloquium on Heterocyclic Chemistry, Reading, UK, 13 – 17 Agosto de 2012. ; Xanthones have a rather restricted occurrence among higher plants, being found almost exclusively in Guttiferae and Gentianaceae. Xanthones are sometimes found as polyhydroxylated derivatives, exhibiting valuable biological activities [1], but more often bearing a variety of substituents. Xanthones are well known for th...


Bioactive meroditerpenes from Cystoseira abies-marina, collected from the coast...

Gouveia, Vera L. M.; Seca, Ana M. L.; Barreto, Maria do Carmo; Silva, Artur M. S.; Kijjoa, Anake

3rd Portuguese Meeting on Medicinal Chemistry and 1st Portuguese-Spanish-Brazilian Meeting on Medicinal Chemistry, Aveiro, 28-30 Novembro 2012. ; Many substances isolated from marine organisms have demonstrated to possess interesting biological and pharmacological activities and have been used as leads in the development of new pharmaceutical agents. Marine macroalgae are abundant and structuring organisms of ...


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    Financiadores do RCAAP

Fundação para a Ciência e a Tecnologia Universidade do Minho   Governo Português Ministério da Educação e Ciência Programa Operacional da Sociedade do Conhecimento União Europeia