A5067367458- Free Radicals and Antioxidants
- Photochemistry and Electron Transfer Studies
- Phytochemicals and Antioxidant Activities
- Electron Spin Resonance Studies
- Antioxidant Activity and Oxidative Stress
- Electrochemical Analysis and Applications
- Photodynamic Therapy Research Studies
- Spectroscopy and Quantum Chemical Studies
- Protein Interaction Studies and Fluorescence Analysis
- Porphyrin and Phthalocyanine Chemistry
- Biochemical effects in animals
- bioluminescence and chemiluminescence research
- Surfactants and Colloidal Systems
- Redox biology and oxidative stress
- Photoreceptor and optogenetics research
- Electrocatalysts for Energy Conversion
- Photosynthetic Processes and Mechanisms
- Lipid Membrane Structure and Behavior
- Dye analysis and toxicity
- Advanced Glycation End Products research
- Molecular Sensors and Ion Detection
- Metal complexes synthesis and properties
- Fuel Cells and Related Materials
- Porphyrin Metabolism and Disorders
- Thermodynamic properties of mixtures
Universidad de Santiago de Chile
2015-2025
Instituto de Química y Fisicoquímica Biológicas
2015-2018
Pontificia Universidad Católica de Chile
2009-2012
Universidade Federal do Rio Grande do Sul
2008-2011
Universidade Federal do Rio Grande
2011
University of Ottawa
2003-2008
Instituto de Ciencia y Tecnología de Polímeros
2003
University of Chile
2000
When AAPH is employed as a free radical source, at low concentrations of free, peptide and protein Trp residues, the oxidation mostly induced by alkoxyl radicals. However, high concentrations, both peroxyl radicals are involved.
This study presents a novel photopharmacological strategy to mitigate the cytotoxic effects of apo-hSOD1 S–S , misfolded protein implicated in neurodegenerative diseases.
The chiral-induced spin selectivity effect (CISS) is a breakthrough phenomenon that has revolutionized the field of electrocatalysis. We report first study on electron spin-dependent electrocatalysis for oxygen reduction reaction, ORR, using iron phthalocyanine, FePc, well-known molecular catalyst this reaction. FePc complex belongs to non-precious catalysts group, whose active site, FeN4, emulates catalytic centers biocatalysts such as Cytochrome c. This presents an experimental platform...
We demonstrate from kinetic studies that under the experimental conditions proposed for ORAC protocol, values do not correlate with capacity of antioxidants to trap peroxyl radicals (ROO˙), suggesting a dominant role alkoxyl (RO˙) in assay.
[reaction: see text]. Rate constants for hydrogen abstraction from phenols by a prefluorescent-TEMPO probe are reported. The nitroxide is employed as potential model of peroxyl radicals. works suppression the fluorescence chromophore. restored when abstracts atom to produce diamagnetic hydroxylamine. studied in this project exhibited rate between 0.003 and 0.2 M(-1) s(-1). A deuterium isotope effect 10 TROLOX confirms that mechanism dominated transfer.
A nitroxide prefluorescent probe has been used to evaluate local reactivity of antioxidants in micellar systems. An apparent rate constant that directly reflects the relevance antioxidant hydrophobicity on reaction toward radicals defined. Dramatic increases this parameter for quercetin are shown moving from methanol media: 90 and 230 fold enhancements SDS Triton X100 micelles, respectively. This is a clear consequence favorable partition reactants micelles.
Three different methodologies frequently employed to evaluate the indexes that report antioxidant capabilities of pure compounds and/or complex mixtures antioxidants are applied a series mono- and polyphenols, as well two wine (red white) samples. These based on bleaching stable radical, effect additive upon luminol chemiluminescence induced by peroxyl radicals, fluorescence from dye molecule. Widely responses obtained methodologies. differences interpreted in terms factors (stoichiometric...
Dibenzoylmethane and avobenzone photochemistry involves the formation of transient enol isomers (Z E). Conjugation OH group with carbonyl in these reduces bond energy. A fast reduction pre-fluorescent probe (C343T) was observed after addition to photolysed DBM samples nonpolar solvents. This can be attributed a hydrogen transfer reaction from E accumulated. While no quenching for Z by TEMPO detected laser flash photolysis timescale. Theoretical calculations spin densities distribution...
The photochemical and photophysical properties of 4-(3-hydroxy-2-methyl-4-quinolinoyloxy)-2,2,6,6-tetramethylpiperidine-1-oxyl free radical (QT) have been studied as a prefluorescent probe to monitor processes in polymer films. This methodology takes advantage the efficient intramolecular quenching fluorescence quinoline by paramagnetic nitroxide, which is disabled when TEMPO reacts with carbon-centered radicals. intensity−time profile observed thermal decomposition...
Solvent effects on the kinetics for hydrogen abstraction from a lactone antioxidant were determined alkoxyl and nitroxyl radicals; their reactivity differ by about 7 orders of magnitude. A decrease ∼12 ∼35 H-abstraction tert-butoxyl radicals, respectively, upon changing solvent hexane to acetonitrile. Results isotope studies indicate that properties antioxidants should be attributed enol, not lactone.
Arsenic has been associated with multiple harmful effects at the cellular level. Indirectly these defects could be related to impairment of integrity immune system, in particular lymphoid population. To characterize effect on redox status this population, copper smelter workers and arsenic unexposed donors were recruited for study. We analyzed urine samples lymphocyte enriched fractions from determinate levels proliferation. Moreover, we studied presence oxidative markers MDA, vitamin E SOD...
Pyrogallol red (PGR) presents high reactivity toward reactive (radical and nonradical) species (RS). This property of PGR, together with its characteristic spectroscopic absorption in the visible region, has allowed developing methodologies aimed at evaluating antioxidant capacity foods, beverages, human fluids. These methods are based on evaluation consumption PGR induced by RS inhibition antioxidants. However, present, there no reports regarding degradation mechanism limiting extrapolation...