A5065336088- Free Radicals and Antioxidants
- Antioxidant Activity and Oxidative Stress
- Photochemistry and Electron Transfer Studies
- Phytochemicals and Antioxidant Activities
- Photochromic and Fluorescence Chemistry
- Chemical and Physical Properties in Aqueous Solutions
- Luminescence and Fluorescent Materials
- Process Optimization and Integration
- Advanced Chemical Physics Studies
- Bioactive Compounds and Antitumor Agents
- Lanthanide and Transition Metal Complexes
- Dendrimers and Hyperbranched Polymers
- Molecular Junctions and Nanostructures
- Advanced oxidation water treatment
- Synthesis and Properties of Aromatic Compounds
- Nanocluster Synthesis and Applications
- Plant biochemistry and biosynthesis
- Catalytic Processes in Materials Science
- Chemistry and Chemical Engineering
- Fullerene Chemistry and Applications
Universidad Autónoma Metropolitana
2011-2017
Universidad Nacional Autónoma de México
2013-2016
Rede de Química e Tecnologia
2016
The reactions of caffeine (CAF) with different reactive oxygen species (ROS) have been studied using density functional theory. Five mechanisms reaction considered, namely, radical adduct formation (RAF), hydrogen atom transfer (HAT), single electron (SET), sequential proton (SEPT), and coupled (PCET). SET, SEPT, PCET ruled out for the CAF •OH, O2•−, ROO•, RO• radicals. It was found that is inefficient directly scavenging O2•− •OOCH3 radicals most likely other alkyl peroxyl overall...
Two empirically fitted parameters have been derived for 74 levels of theory. They allow fast and reliable pKa calculations using only the Gibbs energy difference between an acid its conjugated base in aqueous solution (ΔGs(BA)). The were obtained by least-squares fits ΔGs(BA) vs experimental values phenols, carboxylic acids, amines training sets 20 molecules each chemical family. Test 10 per family—completely independent from set—were used to verify reliability fitting method. It was found...
The peroxyl radical scavenging activity of four hydroxycinnamic acid derivatives (HCAD) has been studied in non-polar and aqueous solutions, using the density functional theory. HCAD are: ferulic (4-hydroxy-3-methoxycinnamic acid), p-coumaric (trans-4-hydroxycinnamic caffeic (3,4-dihydroxycinnamic dihydrocaffeic (3-(3,4-dihydroxyphenyl)-2-propionic acid). It was found that polarity environment plays an important role relative efficiency these compounds as scavengers. also solution pH is a...
Several chemical descriptors have been evaluated for thirty polyphenols within the frame of Density Functional Theory (DFT). They were used to investigate donor and accepting electron capabilities, fractional charge transfer feasibility, H ability these compounds. It was found that deactivating free radicals Myricetin has highest activity via transfer, while Galangin piceatannol are best scavengers through single mechanism nucleophilic electrophilic radicals, respectively.
The peroxyl radical scavenging activity of five guaiacol derivatives (GD) has been studied in nonpolar and aqueous solutions, using the density functional theory. GD are guaiacol, vanillin, vanillic alcohol, acid, eugenol. It was found that environment plays an important role these compounds. They were all to react faster solution than media. order reactivity environments be alcohol > eugenol vanillin while, solution, at physiological pH, it becomes acid ≈ vanillin. also as pH increases so...
The most likely deprotonation route of 12 anthocyanidins was elucidated, their p<italic>K</italic><sub>a</sub>s are calculated and used to estimate the populations different species depending on pH.
The reactions of uric and 1-methyluric acids in nonpolar environments, as well those the corresponding urate anions aqueous solution, with (•)OH, (•)OCH(3), (•)OOH, (•)OOCH(3) have been studied using density functional theory. Different mechanisms taken into account, their relative importance on antiradical activity these compounds is analyzed. Both methyluric are better scavengers solution than media, which indicates that most active species. free radical scavenging was found to be...
Abstract The reactions of caffeine's main metabolites [paraxanthine, theobromine, theophylline, and 1‐methylxanthine] with • OH, OCH 3 , OOH, OOCH in nonpolar polar environments, have been studied using the density functional theory. Different mechanisms reaction taken into account their relative importance on antioxidant activity these compounds has assessed. free radical scavenging was found to be excellent for moderate negligible peroxy radicals. results from present work indicate that...
A new family of free radicals, that are soluble in water and stable at all pH values, were recently synthesized used to assess the antiradical capacity several polyphenols. In present work, density functional calculations investigate single electron transfer reactions between these radicals polyphenols aqueous solution. The quantification is a challenge, particularly for polyphenols, since they become unstable under experimental conditions. It was found from newly developed can be efficiency...