Consulta: creatorFacets:"LISSI,EDUARDO"
Registros recuperados: 4
Data/hora: 01/06/2024 07:41:05

A Pyranine based Procedure for Evaluation of the Total Antioxidant Potential (TRAP) of Polyphenols: A Comparison with closely related Methodologies
Provedor de dados: 48
Autores: CAMPOS,ANA MARÍA; SOTOMAYOR,CARLOS PATRICIO; PINO,EDUARDO; LISSI,EDUARDO.
A novel procedure for the evaluation of total reactive antioxidant potentials (TRAP) is described. The method is based on the measurement of the bleaching of pyranine by peroxyl radicals. The addition of the antioxidants produces a clear induction time whose magnitude is directly related to the antioxidant concentration. A comparison of the values obtained with those reported employing closely related methodologies shows that the results are significantly affected by the substrate employed to monitor the steady state free radical concentration. Possible sources of this dependence are discussed
Tipo: Journal article
Palavras-chave: Peroxyl radicals; Polyphenols; Pyranine; Total reactive antioxidant potential.
Ano: 2004
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602004000200015

A comparison of methods employed to evaluate antioxidant capabilities
Provedor de dados: 48
Autores: PEREZ,DRUSO D; LEIGHTON,FEDERICO; ASPEE,ALEXIS; ALIAGA,CAROLINA; LISSI,EDUARDO.
Thrce ditferent methodologies frequently employed to evaluate the indexes that report the antioxidant capabilities of pure compounds and/or complex mixtures of antioxidants are applied to a series of mono- and polyphenols, as well as to two wine (red and white) samples. These methodologies are based on the bleaching of a stable radical, the effect of the additive upon luminol chemiluminescence induced by peroxyl radicals, and the effect of the additive upon the bleaching of the fluorescence from a dye molecule. Widely ditferent responses are obtained from the different methodologies. These differences are interpreted in terms of the different factors (stoichiametric factors and/or reactivities) that determines the indexes evaluated by these different...
Tipo: Journal article
Palavras-chave: ABTS radical bleaching; Antioxidants; C-phycocyanin bleaching; Total antioxidant reactivity; Total reactive antioxidant potential.
Ano: 2000
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602000000200006

Antioxidant effect of 5-amino salicylic acid on copper-mediated LDL oxidation
Provedor de dados: 48
Autores: LÓPEZ-ALARCÓN,CAMILO; SPEISKY,HERNÁN; LISSI,EDUARDO.
The antioxidant effect of 5-Aminosalicylic acid (5-ASA) on copper-mediated LDL oxidation was followed either by the emitted chemiluminiscence (CL) or by UV-vis spectroscopy. 5-ASA addition extends the lag phase in a concentration-dependent manner without changes in the rate of the process in the autoaccelerated phase. The antioxidant behavior of 5-ASA was very similar to that of Trolox, a very efficient water soluble antioxidant. The copper-binding capacity of 5-ASA was evaluated by UV-visible spectroscopy. The addition of copper to a 5-ASA solution increases the absorbance at 332 nm and generates a new band at 298 nm. These changes in the UV-vis spectra indicate formation of a complex between 5-ASA and copper. However, LDL protection by 5-ASA is unrelated...
Tipo: Journal article
Palavras-chave: 5-Aminosalicylic acid; Antioxidant; LDL oxidation.
Ano: 2007
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602007000200006

Methodologies for evaluation of total antioxidant activities in complex mixtures. A critical review
Provedor de dados: 48
Autores: LLESUY,SUSANA; EVELSON,PABLO; CAMPOS,ANA MARIA; LISSI,EDUARDO.
Tipo: Journal article
Ano: 2001
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602001000200009