Determination of the molar extinction coefficient for the ferric reducing/antioxidant power assay

2011 ◽  
Vol 416 (2) ◽  
pp. 202-205 ◽  
Author(s):  
William A. Hayes ◽  
Daniel S. Mills ◽  
Rachel F. Neville ◽  
Jenna Kiddie ◽  
Lisa M. Collins
Keyword(s):  
Extinction Coefficient ◽  
Molar Extinction Coefficient ◽  
Antioxidant Power ◽  
Ferric Reducing Antioxidant Power

scholarly journals Experimental Determination of the Absorption Cross-Section and Molar Extinction Coefficient of Colloidal CdSe Nanoplatelets

2015 ◽  
Vol 119 (47) ◽  
pp. 26768-26775 ◽  
Author(s):  
Aydan Yeltik ◽  
Savas Delikanli ◽  
Murat Olutas ◽  
Yusuf Kelestemur ◽  
Burak Guzelturk ◽  
...  
Keyword(s):  
Experimental Determination ◽  
Cross Section ◽  
Extinction Coefficient ◽  
Absorption Cross Section ◽  
Molar Extinction Coefficient ◽  
Absorption Cross

A method for the determination of the molar extinction coefficient of structure-linked chromophores

1970 ◽  
Vol 2 (4) ◽  
pp. 329-342 ◽  
Author(s):  
J. P. R. Van Dalen ◽  
W. B. A. M. Ahsmann ◽  
P. Van Duijn
Keyword(s):  
Extinction Coefficient ◽  
Molar Extinction Coefficient

scholarly journals Antioxidants: Terminology, Methods, and Future Considerations

Antioxidants ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 297 ◽  
Author(s):  
Khiena Brainina ◽  
Natalia Stozhko ◽  
Marina Vidrevich
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Capacity ◽  
Activity Concentration ◽  
Antiradical Activity ◽  
Antioxidative Activity ◽  
Antioxidant Power ◽  
Trolox Equivalent ◽  
Ferric Reducing Antioxidant Power ◽  
Quality Diet

Unreliable terminology and incompatible units of antioxidant activity/concentration expression lead to the failure of antioxidant clinical trials, ambiguity of conclusions about the effect of a chosen therapy in medicine and evaluation of food quality, diet, difficulties using information in monitoring the training process in sports, etc. Many different terms (antiradical activity, antioxidant activity, antioxidant capacity, antioxidant power, antioxidant ability) and methods: Trolox equivalent capacity assay (TEAC), Ferric Reducing Antioxidant Power assay (FRAP), Cupric Reducing Antioxidant Capacity assay (CUPRAC), antioxidative activity assay (ABTS), the oxygen radical absorbance capacity (ORAC), and different options of electrochemical ones) proposed for the determination of antioxidants are described. Possible approaches to the development of this field of science and practice are considered.

Analytical Determination of Bioactive Compounds as an Indication of Fruit Quality

2012 ◽  
Vol 95 (6) ◽  
pp. 1725-1732 ◽  
Author(s):  
Yong Seo Park ◽  
Buk-Gu Heo ◽  
Kyung-Sik Ham ◽  
Seong-Gook Kang ◽  
Yang-Kyun Park ◽  
...  
Keyword(s):  
Ethyl Acetate ◽  
Bioactive Compounds ◽  
Antioxidant Activities ◽  
Three Dimensional ◽  
Analytical Determination ◽  
Antioxidant Power ◽  
Ferric Reducing Antioxidant Power ◽  
Antioxidant Capacity Assays ◽  
First Time

Abstract The aim of this investigation was to determine the bioactive compounds in kiwifruit as an indication of quality after extraction using methanol and ethyl acetate. Using FTIR and three-dimensional fluorescence spectroscopy and electrospray ionization/MS, the contents of polyphenols, flavonoids, flavanols, and tannins, and the level of the antioxidant activity by 2, 2-azino-bis (3-ethyl-benzothiazoline-6-sulfonic acid) diammonium salt, 1, 1-diphenyl-2-picrylhydrazyl, ferric-reducing/antioxidant power, and cupric reducing antioxidant capacity assays were determined and compared. It was found that the methanol extracts of kiwifruit showed significantly higher amounts of bioactive compounds and antioxidant activities than the ethyl acetate extracts. The cultivar Bidan, in comparison with the classic Hayward, showed significantly higher bioactivity. For the first time, Bidan organic kiwifruit was analyzed for its antioxidant activities and compared with the widely consumed Hayward organic based on its bioactive compounds and fluorescence properties. Relatively high content of bioactive compounds and positive antioxidant and antiproliferative properties of kiwifruit determined by the advanced analytical methods justify its use as a source of valuable antioxidants. The methods used are applicable for bioactivity determination, in general, for any food products.

scholarly journals PENENTUAN KADAR FENOLAT TOTAL DAN AKTIVITAS ANTIOKSIDAN DARI EKSTRAK DAUN DADAP MERAH (Erythrina fusca Lour) SECARA SPEKTROFOTOMETRI UV-Vis

2019 ◽  
Vol 11 (1) ◽  
pp. 09-16
Author(s):  
Epi Supri Wardi ◽  
Zulkarni R Zulkarni R ◽  
Desy Nurdianti
Keyword(s):  
Antioxidant Activity ◽  
Ethyl Acetate ◽  
Phenolic Content ◽  
Ethyl Acetate Extract ◽  
Ethanol Extract ◽  
Hexane Extract ◽  
Total Phenolic ◽  
Antioxidant Power ◽  
Ferric Reducing Antioxidant Power

Determination of total phenolate and antioxidant activity of red leaf extract (Erythrina fusca Lour) was done by UV-Vis spectrophotometry. This study aims to determine the total phenolic content and antioxidant activity of hexane, ethyl acetate and ethanol extract. The extracts were prepared using a non-polar-maseration method with hexane, ethyl acetate and ethanol solvents. The results showed total phenolic concentration using the Folin-Ciocalteu method were 0.412 g/100 g in the hexane extract, 1.782 g/100 g in the ethyl acetate extract and 5.455 g/100 g in the ethanol extract. Antioxidant activity conducted by using FRAP method (Ferric Reducing Antioxidant Power) were obtained 0,682 mmol Fe (II)/100 g at hexane extract, 5,186 mmol Fe (II)/100 g at ethyl acetate extract and 10,591 mmol Fe (II)/100 g on the ethanol extract. The antioxidant activity of gallic acid as standard was 44.356 g mmol Fe (II)/100g.

Citotoxicidade e Ação Antioxidante de uma Fração Extraída da Planta Plectranthus neochilus (Boldo-gambá)

2019 ◽  
Vol 22 (2) ◽  
pp. 85
Author(s):  
Bethânia Alves Avelar-Freitas ◽  
Karine Beatriz Costa ◽  
Marcelo Ottoni ◽  
Alyson Torres de Barros ◽  
Patrícia Machado de Oliveira ◽  
...  
Keyword(s):  
Antioxidant Capacity ◽  
Color Change ◽  
Folk Medicine ◽  
Cytotoxicity Test ◽  
Antioxidant Power ◽  
Viability Assay ◽  
Ion Production ◽  
Ferric Reducing Antioxidant Power ◽  
Isolated Compound

Plectranthus neochilus é uma erva aromática conhecida popularmente como boldo-gambá, usada na medicina popular para tratar dispepsia e insuficiência hepática, usada também com efeito analgésico e anti-inflamatório. Tendo em vista o uso popular da planta, torna-se importante a investigação farmacológica dos compostos isolados de P.neochilus. A avaliação da Citotoxicidade em plantas é de extrema importância para posterior utilização em medicamentos. O objetivo deste trabalho é avaliar concentrações não citotóxicas de 1,6-di-O-acetil-9-deoxiforscolina um composto isolado análogo a forscolina oriundo do extrato hidroalcoólico das folhas e caules de P.neochilus e avaliar se este diterpeno possuicapacidade antioxidante. Para o teste de citotoxicidade foi utilizado o ensaio de viabilidade com sangue total, foi feita a coleta de sangue de 5 voluntários hígidos, e confeccionadas 6 culturas, sendo a primeira controle a segunda um controle de DMSO, que foi utilizado como solvente para o diterpeno e 4 culturas em concentrações diferentes do diterpeno, 40, 20, 10 e 5μg/ml, seguiu-se o protocolo de lise de hemácias com cloreto de amônio e marcou-se com azul de tripan, posteriormente, foi feita a leitura por citometria de fluxo. Também foi analisada a capacidadeantioxidante do diterpeno por meio da determinação do poder de redução do íon ferro, FRAP (do inglês Ferric Reducing Antioxidant Power) em que é analisada a produção do íon Fe2+ a partir da redução do íon Fe3+ presente no complexo 2,4,6-tripiridil-s-triazina (TPTZ). Quando o ocorre a redução, há alteração de cor na solução, a avaliação é realizada por espectrofotômetro em comprimento de onda de 593 nm. Os resultados demonstraram que nas concentrações testadas, 40, 20, 10 e 5 μg/ml o diterpeno extraído da planta P. neochilus não apresentou citotoxicidade seletiva a nenhuma população leucocitária avaliada (linfócitos, monócitos e neutrófilos) e ainda apresentou grande capacidadeantioxidante. Mais estudos devem ser realizados evidenciando os potenciais farmacológicos da planta P. neochilus, bem como de substâncias isoladas a partir de extratos da planta.Palavras-chave: Diterepeno. Citotoxidade. antioxidanteAbstractPlectranthus neochilus is an aromatic herb popularly known as boldo- opossum, used in folk medicine to treat dyspepsia and hepatic insufficiency, also used as analgesic and anti-inflammatory. In view of the popular use of the plant, it becomes important the pharmacological investigation of the compounds isolated from P.neochilus. The evaluation of plant cytotoxicity is of extreme importance for subsequent use in medicinal products. The objective of this study is to evaluate non-cytotoxic concentrations of 1,6-di-O-acetyl-9-deoxyphosphine an isolated compound analogous to forskolin from the hydroalcoholic extract of P.neochilus leaves and stems and to evaluate whether this diterpene has antioxidant capacity. For the cytotoxicity test, the whole blood viability assay was performed, blood was collected from 5 healthy volunteers, and 6 cultures were made, the second control being a DMSO control, which is the diterpene solvent and 4 cultures at different concentrations of diterpene, 40, 20, 10 and 5 μg / ml, followed by the protocol of red blood cell lysis with ammonium chloride and labeled with tripan blue, and then read by flow cytometry. The antioxidant capacity of diterpene was also analyzed by means of the determination of the iron ion reductionpower (FRAP) in which Fe2 + ion production is analyzed from the Fe3 + ion present in complex 2, 4,6-tripyridyl-s-triazine (TPTZ). When the reduction occurs there is a color change in the solution, turning to an intense purple, the evaluation is performed by spectrophotometer at wavelength of 593 nm. The results demonstrated that at the tested concentrations, 40, 20, 10 and 5 μg / ml diterpene extracted from the plant P. neochilus did not present selective cytotoxicity to any leukocyte population evaluated (lymphocytes, monocytes and neutrophils) andstill presented a great antioxidant capacity. Further studies should be performed evidencing the pharmacological potentials of the plant P. neochilus, as well as of substances isolated from extracts of the plant.Keywords: Diterpene, cytotoxicity, antioxidant .

scholarly journals Comparison of Iron Reduction Methods on the Determination of Antioxidants Content in Vegetables Sample

2018 ◽  
Vol 34 (5) ◽  
pp. 2418-2424
Author(s):  
Yefrida Yefrida ◽  
Hamzar Suyani ◽  
Hermansyah Aziz ◽  
Mai Efdi
Keyword(s):  
Strong Correlation ◽  
Iron Reduction ◽  
Antioxidant Power ◽  
Antioxidant Content ◽  
Reduction Methods ◽  
Ferric Reducing Antioxidant Power

Determination of antioxidant content in 14 vegetables has been done using Modified Phenanthroline (MPM), Phenanthroline (PM) and Ferric Reducing Antioxidant Power (FRAP) methods. The SDR values ​​obtained for the MPM and PM methods were (2.65 ± 1.26) % and (3.51 ± 0.88) %, while the recovery values ​​were (100.86 ± 4.45)% and (99.93 ± 3.50) %, respectively. The antioxidant content of vegetables obtained by MPM, PM and FRAP methods were (30.4 ± 1.46 - 515.9 ± 3.32), (25.9 ± 1.13 - 327.3 ± 2.57) and (21.4 ± 0.51 - 371.7 ± 1.10) μmol Fe / g DW, respectively. The antioxidant content obtained with the three methods showed no significant different. The correlation values ​​between MPM - PM, MPM - FRAP, and PM - FRAP methods are 0.9712, 0.9896 and 0.9611, respectively. These values indicate a very strong correlation among the three methods.

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