A5032621278- Phytochemicals and Antioxidant Activities
- Fermentation and Sensory Analysis
- Biochemical Analysis and Sensing Techniques
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Carbohydrate Chemistry and Synthesis
- Computational Drug Discovery Methods
- Free Radicals and Antioxidants
- Protein Structure and Dynamics
- Enzyme Production and Characterization
- Tea Polyphenols and Effects
- Enzyme Catalysis and Immobilization
- Receptor Mechanisms and Signaling
- Glycosylation and Glycoproteins Research
- Metal complexes synthesis and properties
- Enzyme Structure and Function
- Analytical Chemistry and Chromatography
- Photochemistry and Electron Transfer Studies
- Mass Spectrometry Techniques and Applications
- Polysaccharides and Plant Cell Walls
- Biochemical and biochemical processes
- Epigenetics and DNA Methylation
- Biochemical effects in animals
- Plant Gene Expression Analysis
- Olfactory and Sensory Function Studies
Universidade do Porto
2015-2024
Rede de Química e Tecnologia
2015-2024
Ludwig-Maximilians-Universität München
2022-2023
Faculdade de Tecnologia e Ciências
2014-2018
University of Arizona
2017
University of Coimbra
2011
San Antonio College
2011
Quantum mechanics/molecular mechanics ( QM / MM ) methods offer a very appealing option for the computational study of enzymatic reaction mechanisms, by separating problem into two parts that can be treated with different methods. Hence, in formalism, part system which catalysis actually occurs and involves active site, substrates directly participating amino acid residues is at an adequate quantum mechanical level to describe chemistry taking place. For remaining enzyme, does not...
Association between anthocyanins and carbohydrates has drawn attention over the past few years this interaction is of particularly importance in food chemistry since these compounds are often found together plants foodstuffs. This work intended to bring insights on ionic (pectin) two (cyanidin-3-O-glucoside, cy3glc delphinidin-3-O-glucoside, dp3glc). The flavylium cation hemiketal anthocyanin forms was characterized by saturation transfer difference (STD) NMR spectroscopy respective...
Polyphenols may contribute directly to plant-based foodstuffs flavor, in particular astringency and bitterness. In this work, the bitterness of a small library polyphenols from different classes [procyanidin dimers type B, ellagitannins (punicalagin, castalagin, vescalagin) phenolic acid ethyl esters (protocatechuic, ferulic, vanillic esters] was studied by cell-based assay. The bitter taste receptors (TAS2Rs) activated these half-maximum effective concentrations (EC50) each agonist–TAS2Rs...
Carbohydrates perform a wide range of crucial functions in biological systems and are great interest for the food pharmaceutical industries. β-Galactosidase from Escherichia coli catalyzes both hydrolytic breaking very stable glycosidic bond lactose series transglycosylation reactions. These reactions development new carbohydrate molecules, as well optimization their syntheses. In this work we have used computational methods to study catalytic mechanism hydrolysis set distinct retaining...
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...
The gastric absorption of red wine anthocyanins was evaluated using a MKN-28 cell barrier model. Anthocyanin transport not affected by the presence 4% ethanol and decreased with increase pH. Gastric cells pretreated were found to anthocyanin transport. d-(+)-glucose decrease uptake, suggesting involvement glucose transporters. RT-PCR assays revealed that GLUT1, GLUT3, MCT1 transporters expressed in cells. Computational studies performed provide structural characterization binding site hGLUT1...
Abstract Anthocyanins may protect against a myriad of human diseases. However few studies have been conducted to evaluate their bioavailability so absorption mechanism remains unclear. This study aimed the role two glucose transporters (GLUT1 and GLUT3) in anthocyanins gastric epithelial cells (MKN-28) by using gold nanoparticles silence these transporters. were purified from purple fleshed sweet potatoes grape skin. Silencing GLUT1 and/or GLUT3 mRNA was performed adding AuNP@GLUT1...
Malvidin-3-<italic>O</italic>-coumaroylglucoside molecules self-associate, with this interaction occurring mainly by dispersive contacts (direct π–π stacking and van der Waals interactions).
In this work, sensations elicited by catechin and procyanidins in comparison with those gallocatechin prodelphinidins were evaluated means of a sensory panel. To obtain further insights into the mechanisms action, molecular dynamics (MD) simulations saturation transfer difference nuclear magnetic resonance (STD NMR) experiments have been performed. Results showed clear differences between 2 types flavanols. Dihydroxylated B-ring flavanols more astringent, bitter, dry, rough, unripe,...
Human skin is commonly described as a particularly dynamic and complex environment, with physiological balance continuously orchestrated by numerous internal external factors. Intrinsic aging, exposure to UV radiation pathogens are some of the key players that account for dermatological alterations ailments. In this regard, study intended explore potential skin-health beneficial properties group molecules belonging anthocyanin family: cyanidin- malvidin-3-O-glucosides their structurally...
The kinetics, thermodynamics, and degradation of malvidin mono- diglucosides were studied following a holistic approach by extending to the basic medium. In acidic conditions, reversible kinetics flavylium cation toward equilibrium is controlled hydration cis–trans isomerization steps, while in medium, OH– nucleophilic addition anionic quinoidal bases slowest step. There pH range (transition pHs), between paradigms, that includes physiological (7.4), where reactions occur faster, preventing...
Polyphenols are plant secondary metabolites commonly present in the human diet that possess ability to bind and inhibit digestive proteins. In study, kinetic measurements of porcine pancreatic elastase (PPE) activity were determined using Suc-(Ala)3-p-nitroanilide as substrate polyphenolic compounds inhibitors. A positive relationship between degree polyphenol polymerization capacity polyphenols PPE was observed. Procyanidins with a molecular weight at least 1154 Da necessary observe...
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...
It is known that interactions between wine flavanols and salivary proline-rich proteins (PRPs) are one of the main factors responsible for astringency. The addition commercial yeast mannoproteins (MPs) to wines has been pointed as a possible tool modulate excessive astringency due lack phenolic maturity at harvest time might occur consequence global climate change. aim this work was study by isothermal titration calorimetry molecular dynamics simulation mechanisms which could elicited...
The ionization states of amino acids influence the structure, function, stability, solubility, and reactivity proteins are difficult to determine unambiguously by experimental means. Thus, it is very important be able them theoretically with high reliability. We have analyzed how well DFT functionals, often used characterize complex large models such as proteins, describe zero-point-exclusive proton affinity at 0 K, PAel0K, for ionizable side chains lysine (Lys), histidine (His), arginine...