Results 221 to 230 of about 57,523 (263)

Radical scavenging ability of polyphenolic compounds towards DPPH free radical

Talanta, 2007
Free radical scavenging activity of different polyphenolic compounds commonly present in wine has been evaluated using DPPH method. The experiments were performed with different amounts of phenols within the linear interval of response and with an excess of DPPH in all cases.
D, Villaño, M S, Fernández-Pachón, M L, Moyá, A M, Troncoso, M C, García-Parrilla   +4 more
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DPPH and oxygen free radicals as pro-oxidant of biomolecules

Toxicology in Vitro, 2008
Numerous investigations exist about the alterations that oxygen free radicals can provoke on biomolecules; these modifications can be prevented and/or reversed by different antioxidants agents. On the other hand, 2,2-diphenyl-1-picrylhydrazyl radical (DPPH), a stable nitrogen synthetic radical, is used to evaluate the antioxidant capacity of medicinal ...
Letelier Muñoz, María Eugenia, Molina Berríos, Alfredo Enrique, Cortés Troncoso, Juan, Jara Sandoval, José, Holst, Marianne, Palma, Karina, Montoya, Margarita, Miranda, Dante, González Lira, Víctor   +8 more
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A theoretical investigation on DPPH radical-Scavenging mechanism of edaravone

Bioorganic & Medicinal Chemistry Letters, 2003
The mechanism of edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one) to scavenge DPPH radical is clarified by density functional theory (DFT) calculations. It is revealed that H-atom-abstraction rather than electron-transfer reaction is involved in the radical-scavenging process of edaravone, and H-atom at position 4 is readily to be abstracted.
Lan-Fen, Wang, Hong-Yu, Zhang
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Detection and activity evaluation of radical scavenging compounds by using DPPH free radical and on-line HPLC-DPPH methods

European Food Research and Technology, 2002
The antiradical activity of crude extracts (80% methanol, 20% water) of S. officinalis, S. glutinosa, S. sclarea and S. aethiopis was determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH·) radical scavenging method. For validation of this method several well known antioxidants (ascorbic acid-6-palmitate, gallic, chlorogenic, ferulic, caffeic, uric,
Donata Bandonienė, Michael Murkovic, Werner Pfannhauser, Petras Venskutonis, Dainora Gruzdienė   +4 more
openaire   +1 more source

DPPH radical scavenging activity of paracetamol analogues

Tetrahedron, 2012
Biochemical studies suggest a direct relationship between the radical scavenging activity of paracetamol (I) and its antipyretic and analgesic action. To evaluate the effect of chemical modifications on the radical scavenging activity of compounds of type I, analogues 1e14 were prepared and submitted to a stable free radical (DPPH; 1,1-diphenyl-2 ...
Alisi, Maria Alessandra, Brufani, Mario, Cazzolla, Nicola, Ceccacci, Francesca, Dragone, Patrizia, Felici, Marco, Furlotti, Guido, Garofalo, Barbara, La Bella, Angela, Lanzalunga, Osvaldo, Leonelli, Francesca, Marini Bettolo, Rinaldo, Maugeri, Caterina, Migneco, Luisa Maria, Russo, Vincenzo   +14 more
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Kinetic and thermodynamic parameters for the equilibrium reactions of phenols with the dpph? radical

Chemical Communications, 2006
The kinetics and energetics of the reversible reaction of phenols with the dpph. radical have been studied; steric shielding of the divalent N by the o-NO2 in dpph. seems to be the main cause of the entropic barriers of this reaction.
Foti M C, Daquino C
openaire   +3 more sources

Probing Solvation in Ionic Liquids via the Electrochemistry of the DPPH Radical

Journal of the American Chemical Society, 2012
The electrochemistry of the radical species 2,2-diphenyl-1-picrylhydrazyl, DPPH, has been studied in a range of common ionic liquids and its voltammetric response found to vary with the choice of anion. The trend observed is used to provide a relative Lewis basicity scale of nine ionic liquids commonly used as solvents.
Taylor, Alasdair W., Puttick, Simon, Licence, Peter   +2 more
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Structures of the radical (DPPH) oxidation products of dihydrocapsaicin

Tetrahedron Letters, 2002
Dihydrocapsaicin was oxidized with 2,2-diphenyl-1-picrylhydrazyl (DPPH), a free radical, and the products were analyzed by spectroscopic means.
Tetsuya Nakamura, Takashi Ooi, Kentaro Kogure, Miki Nishimura, Hiroshi Terada, Takenori Kusumi   +5 more
openaire   +1 more source

Free‐Radical‐Scavenging Effect of Carbazole Derivatives on DPPH and ABTS Radicals

Journal of the American Oil Chemists' Society, 2007
AbstractThe major objective was to measure the trolox (6‐hydroxy‐2,5,7,8‐tetramethylchroman‐2‐carboxylic acid) equivalent antioxidant capacity (TEAC) of carbazole derivatives (Ar2NHs) by means of scavenging 2,2′‐diphenyl‐1‐picrylhydrazyl (DPPH) and the 2,2′‐azinobis(3‐ethylbenzothiazoline‐6‐sulfonate) radical cation (ABTS+·).
You‐Zhi Tang, Zai‐Qun Liu
openaire   +1 more source

High-Throughput Relative DPPH Radical Scavenging Capacity Assay

Journal of Agricultural and Food Chemistry, 2006
A high-throughput relative 2,2-diphenyl-1-picryhydrazyl (DPPH) radical scavenging capacity (RDSC) assay was developed and validated in the present study. This RDSC assay is easy to perform and has acceptable accuracy (90-110% recovery), precision [3.9-7.0% pooled relative standard deviation (RSD)], and reproducibility (2.2 and 3.5% interday and ...
Zhihong, Cheng, Jeffrey, Moore, Liangli, Yu   +2 more
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