A5002212414- Photochemistry and Electron Transfer Studies
- Porphyrin and Phthalocyanine Chemistry
- Photodynamic Therapy Research Studies
- Electrochemical Analysis and Applications
- Free Radicals and Antioxidants
- Spectroscopy and Quantum Chemical Studies
- Antioxidant Activity and Oxidative Stress
- Analytical Chemistry and Sensors
- Surfactants and Colloidal Systems
- Electrochemical sensors and biosensors
- Photoreceptor and optogenetics research
- Nanoplatforms for cancer theranostics
- TiO2 Photocatalysis and Solar Cells
- Advanced Photocatalysis Techniques
- Nanoparticles: synthesis and applications
- Lanthanide and Transition Metal Complexes
- Protein Interaction Studies and Fluorescence Analysis
- Conducting polymers and applications
- Molecular Sensors and Ion Detection
- Microencapsulation and Drying Processes
- Light effects on plants
- bioluminescence and chemiluminescence research
- Photosynthetic Processes and Mechanisms
- Metal complexes synthesis and properties
- Luminescence and Fluorescent Materials
National University of Santiago del Estero
2015-2024
Consejo Nacional de Investigaciones Científicas y Técnicas
2015-2024
Instituto Multidisciplinario de Biología Vegetal
2016
Instituto de Biología Molecular y Celular de Rosario
2015
National University of Rosario
2015
Instituto de Química del Noroeste Argentino
2008-2012
Max Planck Institute for Biophysical Chemistry
2012
National University of Tucumán
2009
National University of Río Cuarto
1993-2007
Universidade Estadual de Campinas (UNICAMP)
2003-2006
The thermal degradation kinetics of the main carotenoids cashew apple in a juice model system was studied by HPLC and related to changes its CIELAB color parameters. Similar isomerization equilibrium constants activation energies were observed for both all-trans-β-carotene all-trans-β-cryptoxanthin. curves decay showed biphasic behavior that best fitted biexponential equation. For same heating conditions (60 or 90 °C), similar rate fast (γ1) slow (γ2) decays obtained chemical (carotenoids)...
Abstract The gene slr1393 from Synechocystis sp. PCC6803 encodes a protein composed of three GAF domains, PAS domain, and histidine kinase domain. GAF3 is the sole domain able to bind phycocyanobilin (PCB) as chromophore accomplish photochemistry: switching between red‐absorbing parental green‐absorbing photoproduct state ( λ max =649 536 nm, respectively). Conversions in both directions were followed by time‐resolved absorption spectroscopy with separately expressed Slr1393. Global fit...
The impact of corn silage supplementation and post mortem aging on the antioxidant status in longissimus thoracis et lumborum (LTL) muscle was assessed using micro-spectroscopic techniques. A total 30 Braford steers were utilized study. Of these, 15 animals supplemented with for 120 days, while remaining fed exclusively pasture. LTL steak samples aged 2, 7, 14, 21 days at a temperature 2 ± 1°C, under conditions darkness vacuum. Several colorimetric assays employed to evaluate capacity both...
Background/Objectives: Parietin (PTN), a blue-light absorbing pigment from Teloschistes spp. lichens, exhibits photosensitizing properties via Type I (superoxide anion, O2•-) and II (singlet oxygen, 1O2) mechanism, inactivating bacteria in vitro after photo-stimulation. We evaluate the antifungal activity of PTN against Candida tropicalis biofilms under actinic irradiation, its role O2•- 1O2 production, cellular stress response. Methods: Minimum Inhibitory Concentration (MIC) was determined...
The photodynamic activities of the free-base 5,10,15,20-tetrakis(4-methoxyphenyl)porphyrin (TMP) and their metal complexes with zinc(II) (ZnTMP), copper(II) (CuTMP) cadmium(II) (CdTMP) have been compared in two systems: reverse micelle n-heptane/sodium bis(2-ethylhexyl)sulfosuccinate/water bearing photooxidizable substrates Hep-2 human larynx carcinoma cell line. quantum yields singlet molecular oxygen, O2(1Δg), production (ΦΔ) TMP, ZnTMP CdTMP tetrahydrofuran, were determined yielding...
The photosensitized isomerization reaction of the natural cis carotenoid bixin (methyl hydrogen 9'-cis-6, 6'-diapocarotene-6, 6'-dioate) with rose bengal or methylene blue as sensitizer in acetonitrile/methanol (1:1) solution was studied using UV-vis spectroscopy, high-performance liquid chromatography (HPLC), and time-resolved spectroscopic techniques, such laser-flash photolysis singlet oxygen phosphorescence detection. In both N(2)- air-saturated solutions, main product formed...
The total structural volume (ΔVstr) and enthalpy (ΔHstr) changes associated with the formation of triplet metal-to-ligand charge transfer (3MLCT) state were determined by laser-induced optoacoustic spectroscopy for complexes Ru(bpy)32+, Ru(bpy)2(CN)2, Ru(bpy)(CN)42- in aqueous solutions 0.1 M monovalent salts. For cyano (bound to water through hydrogen bonds) values ΔVstr vs ΔHstr exhibited a linear relationship salt series, whereas Ru(bpy)32+ independent salt. This correlation is...
The singlet oxygen (1O2) quenching and free radical (DPPH•, ABTS• + O2• −) scavenging ability of three structurally-related flavonoids (7-hydroxyflavanone HF, 2′,4′-dihydroxychalcone DHC 3,7-dihydroxyflavone DHF) present in the Argentinean native shrub Zuccagnia punctata Cav. were studied solution by combining electrochemical kinetic measurements, mass spectroscopy, end-point antioxidant assays computational calculations. results showed that properties these depend on several factors, such...
UV-A radiation (320-400 nm) induces damage to the DNA molecule and its components through photosensitized reactions. Biopterin (Bip) photoproducts 6-formylpterin (Fop) 6-carboxypterin (Cap) accumulate in skin of human beings suffering from vitiligo, a depigmentation disorder where protection against UV fails because lack melanin. This study was aimed evaluate photosensitizing properties oxidized pterins present elucidate mechanisms involved oxidation purine nucleotides by vitro. For this...
Photosensitized reactions contribute to the development of skin cancer and are used in many applications. Photosensitizers can act through different mechanisms. It is currently accepted that if photosensitizer generates singlet molecular oxygen ((1) O2 ) upon irradiation, target molecule undergo oxidation by this reactive species reaction needs dissolved proceed, therefore classified as (1) -mediated (type II mechanism). However, assumption not always correct, an example, a study on...
The influence of the medium heterogeneity upon bimolecular rate constants for physical quenching, kq, and chemical kr, singlet molecular oxygen O2(1Δg) by seven natural three synthetic carotenoids (CAR) with different substituent patterns was studied in a reverse micelle system sodium bis(2-ethylhexyl)sulfosuccinate, hexane water. Because generated inside water pools micelles photosensitization water-soluble dye rose bengal CAR are mainly located external pseudophase, quenching process...