Marcelo D. Catarino, Ana Silva, Maria Teresa Cruz, Nuno Mateus, Artur M. S. Silva, Susana M. Cardoso,
Due to their large spectrum of bioactive properties, much attention has recently been drawn to phlorotannins-i.e., phenolic compounds characteristic from brown macroalgae. This study aimed to evaluate the antioxidant and anti-inflammatory properties of
Tópico(s): Phytochemicals and Antioxidant Activities
2020 - Multidisciplinary Digital Publishing Institute | International Journal of Molecular Sciences
Joana Oliveira, Nuno Mateus, Artur M. S. Silva, Víctor de Freitas,
The main species in the acid-base equilibria of two pyranoanthocyanins (vitisins B), pyranomalvidin-3-glucoside I and pyranomalvidin-3-O-coumaroylglucoside II, and the respective pK(a) were determined using NMR, visible spectroscopy, and mass spectrometry techniques. The three equilibria involve protonation of the pyranoflavylium cation of vitisin B (pK(a1)) and two deprotonations (pK(a2) and pK(a3)). For pigment I, the values obtained through the titration curves of the chemical shift of some protons ...
Tópico(s): Microbial Metabolism and Applications
2009 - American Chemical Society | The Journal of Physical Chemistry B
Susana González‐Manzano, José Pérez-Alonso, Yolanda Salinas‐Moreno, Nuno Mateus, Artur M. S. Silva, Víctor de Freitas, Celestino Santos‐Buelga,
Tópico(s): Tea Polyphenols and Effects
2008 - Elsevier BV | Journal of Food Composition and Analysis
Carlos A. D. Sousa, Nuno Mateus, Artur M. S. Silva, Ana M. Gonzaléz‐Paramás, Celestino Santos‐Buelga, Víctor de Freitas,
A new pigment, resulting from the reaction between malvidin 3-glucoside and catechin in the presence of vanillin, was detected in a model solution. This newly formed anthocyanin-aryl-flavanol adduct was structurally characterized by 1D and 2D NMR and mass spectrometry, and its chromatic characteristics were studied by UV–Vis techniques. The new pigment was shown to have a wavelength of maximum absorption in the visible region (λmax) of 549 nm, conferring on it a purple colour, and a molar extinction ...
Tópico(s): Fermentation and Sensory Analysis
2006 - Elsevier BV | Food Chemistry
Nuno Mateus, Artur M. S. Silva, Julián C. Rivas‐Gonzalo, Celestino Santos‐Buelga, Víctor de Freitas,
Two newly formed anthocyanin-derived pigments that revealed unique spectroscopic features, showing maximum absorption in their UV−vis spectra at 575 nm, were isolated by TSK Toyopearl HW-40 (S) gel column chromatography and semipreparative HPLC from an aged Port red wine. Further characterization by ESI/MS and NMR (1H, gCOSY) showed them to belong to a new class of pigments described here for the first time, the structure of which consisted of a pyranoanthocyanin moiety linked to a flavanol by a vinyl ...
Tópico(s): Horticultural and Viticultural Research
2003 - American Chemical Society | Journal of Agricultural and Food Chemistry
Nuno Mateus, Artur M. S. Silva, Celestino Santos‐Buelga, Julián C. Rivas‐Gonzalo, Víctor de Freitas,
Three newly formed Port wine pigments were isolated by Toyopearl HW-40(s) gel chromatography and semipreparative HPLC. Furthermore, the pigments were identified by mass spectrometry (LC/MS) and NMR techniques (1D and 2D). These anthocyanin-derived pigments showed UV-visible spectra different from those of the original grape anthocyanins. These pigments correspond to malvidin 3-glucoside linked through a vinyl bond to either (+)-catechin, (-)-epicatechin, or procyanidin dimer B3 [(+)-catechin-(+)-catechin]. NMR ...
Tópico(s): Tea Polyphenols and Effects
2002 - American Chemical Society | Journal of Agricultural and Food Chemistry
Nuno Mateus, Artur M. S. Silva, Joseph Vercauteren, Víctor de Freitas,
Several anthocyanin-derived pigments that showed UV-visible spectra different from those of the original grape anthocyanins were detected by HPLC-DAD analysis in 1-year-old bottled Port wines from the Douro region. Among these, three malvidin 3-glucoside derived pigments were detected in large amounts, representing approximately 60% of the total anthocyanidin monoglucosides content. These pigments were isolated, purified, and identified by LSI-MS and NMR ((1)H, DQF-COSY, ROESY, HSQC, and HMBC) techniques. ...
Tópico(s): Phytochemicals and Antioxidant Activities
2001 - American Chemical Society | Journal of Agricultural and Food Chemistry
Marcelo D. Catarino, Catarina Marçal, Teresa Bonifácio-Lopes, Débora A. Campos, Nuno Mateus, Artur M. S. Silva, Manuela Pintado, Susana M. Cardoso,
Recent studies indicate that plant polyphenols could be pointed as potential prebiotic candidates since they may interact with the gut microbiota, stimulating its growth and the production of metabolites. However, little is known about the fate of brown seaweeds' phlorotannins during their passage throughout the gastrointestinal tract. This work aimed to evaluate the stability and bioaccessibility of
Tópico(s): Phytoestrogen effects and research
2021 - Multidisciplinary Digital Publishing Institute | Marine Drugs
Marcelo D. Catarino, Sónia J. Amarante, Nuno Mateus, Artur M. S. Silva, Susana M. Cardoso,
According to the WHO, cancer was responsible for an estimated 9.6 million deaths in 2018, making it the second global leading cause of death. The main risk factors that lead to the development of this disease include poor behavioral and dietary habits, such as tobacco use, alcohol use and lack of fruit and vegetable intake, or physical inactivity. In turn, it is well known that polyphenols are deeply implicated with the lower rates of cancer in populations that consume high levels of plant derived ...
Tópico(s): Free Radicals and Antioxidants
2021 - Multidisciplinary Digital Publishing Institute | Foods
André Sousa, Nuno Mateus, Artur M. S. Silva, Nicolás Vivas, Marie‐Françoise Nonier, Isabelle Pianet, Víctor de Freitas,
Condensation reactions of malvidin-3-glucoside with two representative oak wood furanic aldehydes (furfural and methylfurfural) were conducted in wine-like model solutions. Methylfurfural led to the formation of malvidin-3-glucoside-methylfurfural (603 m/z), whereas furfural led to the formation of malvidin-3-glucoside-furfural (589 m/z). The latter was structurally characterized by 1D and 2D NMR, allowing an elucidation of the formation mechanism of these anthocyanin-furanic aldehyde adducts in the ...
Tópico(s): Biochemical and biochemical processes
2010 - American Chemical Society | Journal of Agricultural and Food Chemistry
Nuno H.C.S. Silva, Artur Filipe Rodrigues, Isabel F. Almeida, Paulo Costa, Catarina Rosado, Carlos Pascoal Neto, Armando J. D. Silvestre, Carmen S. R. Freire,
Bacterial cellulose (BC) membranes were explored as novel nanostructured transdermal delivery systems for diclofenac sodium salt (a typical non-steroidal anti-inflammatory drug). Diclofenac sodium salt loaded BC membranes were prepared through a simple methodology, using glycerol as plasticizer, and characterized in terms of structure, morphology and swelling behavior. The membranes were very homogeneous, quite flexible and presented a considerably higher swelling behavior when compared with pure ...
Tópico(s): Advanced Cellulose Research Studies
2014 - Elsevier BV | Carbohydrate Polymers
Produção Nacional
Revisado por pares
Sabrina Epiphânio, Marta Campos, Ana Pamplona, Daniel Carapau, Ana C. Pena, Ricardo Ataíde, Carla A. A. Monteiro, Nuno Damácio de Carvalho Félix, Artur Costa-Silva, Cláudio Romero Farias Marinho, Sérgio Dias, Maria M. Mota,
The spectrum of the clinical presentation and severity of malaria infections is broad, ranging from uncomplicated febrile illness to severe forms of disease such as cerebral malaria (CM), acute lung injury (ALI), acute respiratory distress syndrome (ARDS), pregnancy-associated malaria (PAM) or severe anemia (SA). Rodent models that mimic human CM, PAM and SA syndromes have been established. Here, we show that DBA/2 mice infected with P. berghei ANKA constitute a new model for malaria-associated ALI. ...
Tópico(s): Complement system in diseases
2010 - Public Library of Science | PLoS Pathogens
Marcelo D. Catarino, Artur M. S. Silva, Nuno Mateus, Susana M. Cardoso,
Phlorotannins are phloroglucinol-based phenolic compounds, occurring particularly in brown macroalgae, that have been recognized for their promising bioactive properties. In this study, the extraction of phlorotannins from Fucus vesiculosus was evaluated with particular emphasis on the influential parameters, including the solvent concentration, solvent-solid ratio, extraction temperature and extraction time, using a single-factor design followed by a Box-Behnken design. The maximum total phlorotannin ...
Tópico(s): Echinoderm biology and ecology
2019 - Multidisciplinary Digital Publishing Institute | Marine Drugs
Jingren He, Artur M. S. Silva, Nuno Mateus, Víctor de Freitas,
A new group of pyranoanthocyanin-derived polyphenolic compounds was recently found to occur in aged wines and named as oxovitisins, the spectrum of which displayed only a pronounced broad absorption peak around 370 nm in the UV region, being quite different from that of anthocyanin-like chromenylium pigments which present maximum absorption in the visible wavelength ranges. The possibilities and reaction conditions for the oxidative transformation of anthocyanin type flavylium cations into new type ...
Tópico(s): Chromatography in Natural Products
2011 - Elsevier BV | Food Chemistry
Jingren He, Joana Oliveira, Artur M. S. Silva, Nuno Mateus, Víctor de Freitas,
A new class of stable yellowish pigments with similar unique spectral features, displaying only a pronounced broad band around 370 nm in the UV−vis spectrum, was detected in an aged Port wine fraction obtained by a combination of chromatography on TSK Toyopearl HW-40(s) and Polyamide resins. These compounds were identified by liquid chromatography-diode array detector/electrospray ionization mass spectrometry (LC-DAD/ESI/MS) and shown to be direct oxidative derivatives of carboxy-pyranoanthocyanins ( ...
Tópico(s): Horticultural and Viticultural Research
2010 - American Chemical Society | Journal of Agricultural and Food Chemistry
Luís Cruz, José E. Rodríguez‐Borges, Artur M. S. Silva, Nuno Mateus, Víctor de Freitas,
A strategy for the synthesis of 8-vinylcatechin was developed, which involves (+)-catechin silylation with TBDMS-Cl, followed by bromination with NBS, a cross-coupling Suzuki reaction with vinylboronic acid pinacol ester and cleavage of TBDMS groups with TBAF, affording the 8-vinylcatechin. Keywords: (+)-Catechin, silylation, bromination, Suzuki coupling, desilylation, 8-vinylcatechin
Tópico(s): Tea Polyphenols and Effects
2008 - Bentham Science Publishers | Letters in Organic Chemistry
Luís Cruz, Natércia Teixeira, Artur M. S. Silva, Nuno Mateus, José E. Rodríguez‐Borges, Víctor de Freitas,
Reactions between malvidin-3-glucoside (mv3glc) and 8-vinylcatechin were carried out to synthesize pyranomv3glc−(+)-catechin pigment and to study the formation of intermediates. A rapid decrease of mv3glc content concomitant with the formation of more complex structures such as mv3glc−vinylcatechin [precursor of pyranomv3glc−(+)-catechin pigment] and mv3glc−divinylcatechin was observed. On the other hand, 8-vinylcatechin undergoes acid-catalyzed dimerization in model wine solution, giving rise to ...
Tópico(s): Phytochemicals and Antioxidant Activities
2008 - American Chemical Society | Journal of Agricultural and Food Chemistry
Joana Oliveira, Víctor de Freitas, Artur M. S. Silva, Nuno Mateus,
Three new anthocyanin-derived pigments were found to occur in a 2-year-old Port red wine. Their structures were elucidated through LC/DAD-MS and NMR analysis and were found to correspond to a pyranoanthocyanin moiety linked to substituted cinnamyl substituents. The structures of these compounds are very similar to the one already reported for portisins, with a phenolic moiety replacing the catechin moiety. The newly formed anthocyanin-derived compounds display a bathochromic shift of the λmax (∼540 ...
Tópico(s): Biochemical and biochemical processes
2007 - American Chemical Society | Journal of Agricultural and Food Chemistry
Pedro Cardoso, Israel Tojal da Silva, Nuno Oliveira, Artur R. M. Serrano,
Abstract 1. Fields such as ecology, macroecology, and conservation biology rely on accurate and comparable data. This is especially important for mostly unknown and megadiverse taxa such as spiders and regions such as the Mediterranean. Short‐term sampling programmes are increasingly seen as the best option for sampling spiders. Comparability of results, however, demands standard procedures both in methodology and in sampling period. Cost‐efficiency dictates that this period should be the most species ...
Tópico(s): Spider Taxonomy and Behavior Studies
2007 - Wiley | Ecological Entomology
Jingren He, Celestino Santos‐Buelga, Artur M. S. Silva, Nuno Mateus, Víctor de Freitas,
Two newly formed yellow pigments that revealed unique spectral features were detected and isolated from an aged Port red wine by TSK Toyopearl HW-40(s) gel chromatography and characterized by UV−visible spectrophotometry, 1H NMR and 13C NMR, and mass spectrometry (LC-ESI/MS). The UV−vis spectra of these pigments showed maximum absorption at 478 nm that is significantly hypsochromically shifted from those of original grape anthocyanins and other pyranoanthocyanins, exhibiting a more yellow hue in ...
Tópico(s): Horticultural and Viticultural Research
2006 - American Chemical Society | Journal of Agricultural and Food Chemistry
Pedro Cardoso, Israel Tojal da Silva, Nuno Oliveira, Artur R. M. Serrano,
Tópico(s): Genetic diversity and population structure
2004 - Elsevier BV | Biological Conservation
Pedro Cardoso, Israel Tojal da Silva, Nuno Oliveira, Artur R. M. Serrano,
A number of alternative approaches have been suggested during recent years to predict species richness of a given taxa, while retaining information on the identities of the observed individuals. Such information can be extremely useful for choosing conservation priority areas, either by using simple richness values or, preferentially, by considering the complementarity of potential sites. Among the most popular approaches is the use of higher taxa surrogates. Both family and genus richness are here ...
Tópico(s): Genetic diversity and population structure
2003 - Elsevier BV | Biological Conservation
Madalena Martins, Ana Loureiro, Nuno G. Azóia, Carla Silva, Artur Cavaco‐Paulo,
Needs from medical and cosmetic areas have led to the design of novel nanosized emulsions and solid-in-oil dispersions of proteins. Here, we describe the production of those emulsions and dispersions using high-energy methodologies such as high-pressure homogenization or ultrasound. Recent work has resulted in new mechanistic insights related to the formation of protein emulsions and dispersions. The production method and composition of these formulations can determine major parameters such as size, ...
Tópico(s): Lipid Membrane Structure and Behavior
2016 - Elsevier BV | Trends in biotechnology
João Pissarra, Sandra Lourenço, Ana M. Gonzaléz‐Paramás, Nuno Mateus, Celestino Santos‐Buelga, Artur M. S. Silva, Víctor de Freitas,
The condensation reaction between malvidin 3-glucoside and catechin mediated by isobutyraldehyde, benzaldehyde, and isovaleraldehyde was conducted in model solutions at two pH values (1.5 and 3.2). The formation of new alkyl/aryl-linked adducts corresponding to the structures malvidin 3-glucoside-isobutylcatechin, malvidin 3-glucoside-benzylcatechin, and malvidin 3-glucoside-3-methylbutylcatechin was respectively observed from each aldehyde. The structural characterization of these new structures ...
Tópico(s): Fermentation and Sensory Analysis
2004 - American Chemical Society | Journal of Agricultural and Food Chemistry
João Pissarra, Sandra Lourenço, Ana M. Gonzaléz‐Paramás, Nuno Mateus, Celestino Santos‐Buelga, Artur M. S. Silva, Víctor de Freitas,
A condensation reaction between malvidin 3-glucoside (mv3gl) and catechin (cat) mediated by acetaldehyde and propionaldehyde was conducted in model solutions at two pH values (at 1.5 and 3.2). Acetaldehyde led to the formation of mv3gl-8-ethyl-8-cat (m/z at 809) widely reported in the literature, whereas propionaldehyde led to the formation of mv3gl-8-propyl-8-cat (m/z at 823) and its structural characterization is elucidated herein for the first time by 1D and 2D NMR. The formation of these alkyl-linked ...
Tópico(s): Fermentation and Sensory Analysis
2004 - Elsevier BV | Food Chemistry
Artur Silva, Jorge Guilherme, Nuno Horta,
Tópico(s): Low-power high-performance VLSI design
2008 - Elsevier BV | Integration
A. Sofia Santos, Daniel Raydan, José Cunha, Nuno Viduedo, Artur M. S. Silva, M. Manuel B. Marques,
N-heterocycles, both saturated and unsaturated, are ubiquitous biologically active molecules that are extremely appealing scaffolds in drug discovery programs. Although classical synthetic methods have been developed to access many relevant N-heterocyclic scaffolds, representing well-established and reliable routes, some do not meet the needs of sustainability. In this context, several advances have been made towards the sustainable synthesis of N-heterocycles. This review focuses on the most recent ...
Tópico(s): Multicomponent Synthesis of Heterocycles
2021 - Multidisciplinary Digital Publishing Institute | Catalysts
Nuno C. Afonso, Marcelo D. Catarino, Artur M. S. Silva, Susana M. Cardoso,
Due to the balanced nutritional value and abundance of bioactive compounds, seaweeds represent great candidates to be used as health-promoting ingredients by the food industry. In this field, Phaeophyta, i.e., brown macroalgae, have been receiving great attention particularly due to their abundance in complex polysaccharides, phlorotannins, fucoxanthin and iodine. In the past decade, brown algae and their extracts have been extensively studied, aiming at the development of well-accepted products ...
Tópico(s): Algal biology and biofuel production
2019 - Multidisciplinary Digital Publishing Institute | Antioxidants
Madalena Martins, Nuno G. Azóia, Artur Ribeiro, Ulyana Shimanovich, Carla Silva, Artur Cavaco‐Paulo,
Transdermal perfusion of a large protein is reported for the first time, using a nanoemulsion of bovine serum albumin (66 kDa) of 160 nm prepared by a solid-in-oil (S/O) process. Molecular dynamics simulations confirmed skin permeation by these formulations, with integration of the protein into the lipid bilayers. These results demonstrate the real possibility of delivering large proteins transdermally for a range of medical and cosmetic applications.
Tópico(s): Proteins in Food Systems
2013 - Elsevier BV | Colloids and Surfaces B Biointerfaces
Madalena Martins, Nuno G. Azóia, Carla Silva, Artur Cavaco‐Paulo,
Oil-in-water proteinaceous micro-emulsions are described as novel methodology for the stabilization of enzymes. Proteins are tightly packed at the oil–water interface of micro-emulsions and it was found that micro-emulsions of laccases enzymes have enhanced stability under high temperatures and ultrasound fields (see graphical abstract scheme and data). This stabilization technique seems to be a promising methodology to apply on other enzyme-based processes where the operational conditions required ...
Tópico(s): Dye analysis and toxicity
2014 - Elsevier BV | Biochemical Engineering Journal