A5071465080- Phytochemicals and Antioxidant Activities
- Fermentation and Sensory Analysis
- Tea Polyphenols and Effects
- Biochemical Analysis and Sensing Techniques
- Molecular Sensors and Ion Detection
- Free Radicals and Antioxidants
- Photochromic and Fluorescence Chemistry
- Biochemical and biochemical processes
- Nanocomposite Films for Food Packaging
- Enzyme Catalysis and Immobilization
- Radical Photochemical Reactions
- Plant biochemistry and biosynthesis
- Plant Gene Expression Analysis
- TiO2 Photocatalysis and Solar Cells
- Luminescence and Fluorescent Materials
- Oxidative Organic Chemistry Reactions
- Antioxidant Activity and Oxidative Stress
- Synthesis of Organic Compounds
- Essential Oils and Antimicrobial Activity
- Microbial Natural Products and Biosynthesis
- Olfactory and Sensory Function Studies
- Horticultural and Viticultural Research
- Dendrimers and Hyperbranched Polymers
- biodegradable polymer synthesis and properties
- Carbohydrate Chemistry and Synthesis
Rede de Química e Tecnologia
2016-2025
Universidade do Porto
2016-2025
Faculdade de Tecnologia e Ciências
2016
Molina Center for Energy and the Environment
2016
Universidade de Brasília
2016
Universidade Nova de Lisboa
2010
University of Aveiro
2008
Universidad de Guadalajara
1996
In the present work, several compounds bearing similar spectroscopic features were found to occur in aged Port wines and respective sediments (lees). The data obtained revealed two new families of with unique characteristics, displaying a wavelength maximum absorption at high visible spectrum ∼730 ∼680 nm. structure these pigments was elucidated by liquid chromatography/diode array detector−mass spectrometry (LC/DAD−MS) nuclear magnetic resonance (NMR), their formation pathway established....
The copigmentation binding constants (K) for the interaction of different copigments with oenin (major red wine anthocyanin) were determined. All tests performed in a 12% ethanol citrate buffer solution (0.2 M) at pH 3.5, an ionic strength adjusted to 0.5 M by addition sodium chloride. Over past years, several studies made and many tested, but none them included prodelphinidin B3 or dimeric-type adduct like oenin-(O)-catechin, probably due difficulty obtaining them. data yielded from this...
Phenolic compounds, namely, hydrolyzable tannins and low molecular weight phenolic were isolated purified from Portuguese cork Quercus suber L. Some of these compounds studied to evaluate their antioxidant activity, including free-radical scavenging capacity (DPPH method) reducing (FRAP method). All tested showed significant antiradical properties. The seemed increase with the presence galloyl groups. Regarding capacity, this structure-activity relationship was not so clear. These also...
The chemical modification of anthocyanins (water-soluble pigments) into more lipophilic compounds is very important to expand their application in the food, medical and cosmetic industries. In this work, synthesis a pure malvidin-3-glucoside-oleic acid ester derivative was achieved by enzymatic catalysis. This approach allowed us synthesize novel compound, malvidin-3-O-(6''-oleoyl)glucoside (Mv3glc-OA), which structurally characterized mass spectrometry for first time NMR spectroscopy....
Biogenic amines (BAs) are biologically active nitrogen-containing compounds formed during the food spoilage process and often related as key markers of quality, safety, freshness. Because their presence in foods at high levels can cause significant health problems, researchers have been focused on developing novel strategies methods for early detection capture these analytes. Herein, water-soluble sulfonated calix[n]arene macrocycles (SC4, SC6, SC8) a pH-sensitive dye...
Reactions between malvidin-3-glucoside (mv3glc) and 8-vinylcatechin were carried out to synthesize pyranomv3glc−(+)-catechin pigment study the formation of intermediates. A rapid decrease mv3glc content concomitant with more complex structures such as mv3glc−vinylcatechin [precursor pigment] mv3glc−divinylcatechin was observed. On other hand, undergoes acid-catalyzed dimerization in model wine solution, giving rise dimers. These compounds also found reaction (+)-catechin mediated by...
This work is focused on the study of antioxidant properties red wine anthocyanin derivatives (carboxypyranoanthocyanins, methylpyranoanthocyanins, oxovitisins, and pyranoanthocyanin-phenolics) derived from malvidin-3-glucoside. Some features were determined using DPPH assay ability to delay lipid peroxidation in a liposome membrane system by monitoring oxygen consumption. The pyranoanthocyanin-phenolics have higher potential than that malvidin-3-glucoside, suggesting addition catechol or...
This work describes the lipophilization reactions of malvidin 3-glucoside with different saturated fatty acid chain lengths using an enzymatic synthesis and study their physical-chemical antioxidant properties. The lipophilic anthocyanins were obtained satisfactory yields (22-40%) after column chromatography purifications, they revealed same appealing chromatic features parent anthocyanin. All compounds characterized by mass spectrometry, confirming regioselective acylation on glucose...
Anthocyanins are water-soluble pigments with limited application in lipophilic matrices such as lipid-based foods and cosmetic formulations. In this work, the liposolubility improvement of cyanidin-3-glucoside (cy3glc) was performed by enzymatic esterification saturated fatty acids variable chain lengths, their thermostabilities were evaluated at different pH values a medium (an aqueous sodium dodecyl sulfate solution) means UV–vis spectroscopy. Overall, cy3glc derivatives showed improved...
Introdução: As doenças autoimunes sistêmicas (DAS) são condições complexas, caracterizadas pela produção de autoanticorpos que atacam diversos órgãos e sistemas do corpo, resultando em inflamação crônica danos teciduais. ferramentas diagnósticas estão constante evolução, com novos biomarcadores sendo identificados. Nos últimos anos, houve também um grande avanço no manejo das sistêmicas. Objetivo: Revisar as atualizações mais recentes diagnóstico Metodologia: A pesquisa é fundamentada uma...
Introdução: O câncer gástrico é uma das principais causas de morbimortalidade em todo o mundo. Embora as abordagens terapêuticas tenham evoluído ao longo últimas décadas, a cirurgia ainda considerada opções no tratamento do gástrico, principalmente casos doença localizada. No entanto, inovações recentes têm procurado otimizar os resultados e minimizar riscos associados à intervenção cirúrgica. Objetivo: Revisar cirúrgico gástrico. Metodologia: A pesquisa fundamentada revisão abrangente da...
Lipophilization technique has been a promising alternative to reduce anthocyanin's chemical instability and increase their lipid affinity. Enzymatic acylation of cyanidin-3-O-glucoside (C3G) extracted from black rice bran was optimized towards the fatty acid donor, solvent, enzyme concentration, temperature parameters. The most lipophilic conjugate (C3G-C8) obtained with 53 % yield at 60 °C, 15 g/L in acetonitrile:DMSO (10:1). Regarding thermostability, an half-life time for C3G-C8 different...
Anthocyanins are amazing plant-derived colorants with highly valuable properties; however, their chemical and color instability issues limit wide application in different food industry-related products such as active intelligent packaging. In a previous study, it was demonstrated that anthocyanins could be stabilized into green plasticizers namely deep eutectic solvents (DESs). this work, the fabrication of edible films by integrating along DESs biocompatible chitosan (CHT)-based...
The chemical equilibria of the pyranomalvidin-3-glucosides linked to (+)-catechin, (−)-epicatechin, and catechol moieties (and respective coumaroylglucoside compounds) were established by means UV−vis spectroscopy. conjugated double bonds among pyranic rings C D provide a higher electronic delocalization that prevents nucleophilic attack water at position 2. Consequently, besides flavylium cation (AH+), bases A, A−, A2− have been identified increasing pH, acidity constants determined...