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has been cited by the following article:

• TITLE: A new method for quantification of total polyphenol content in medicinal plants based on the reduction of Fe(III)/1,10-phenanthroline complexes

  AUTHORS: Mônica Gabriela do Santo, Cecilia Veronica Nunez, Horacio Dorigan Moya

  KEYWORDS: Polyphenols; Medicinal Brazilian Plants; 1, 10-Phenanthroline; Iron (III); Antioxidant Activity

  JOURNAL NAME: Advances in Biological Chemistry, Vol.3 No.6, December 12, 2013

  ABSTRACT: This paper proposes an alternative analytical spectrophotometric method for the total polyphenol quantification in the aqueous extract of plants. When these extracts are added to solutions of Fe(III), in presence of 1,10-phenanthroline, the absorbance values at 551 nm (A511nm) due to the complexes formed are proportional to the total polyphenol concentration expressed as pyrogallic acid (PA). A typical calibration graph of A511nm values vs. PA is linear from 0.16 to 0.64 mg L-1 (r = 0.994, n = 6) with a limit of detection 0.041 mg L-1. The results of the polyphenol content of the aqueous extracts of twenty medicinal Brazilian plants obtained with the proposed method were compared with values using the Folin-Ciocalteu reagent. A paired t-test revealed no statistically significant difference for the species analyzed. The total antioxidant capacity of the same twenty extracts was determined based on the scavenging of stable radical DPPH.