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

作     者：Monica Gabriela do Santo Cecilia Veronica Nunez Horacio Dorigan Moya 

作者机构：Faculdade de Medicina da Fundacao do ABCCEPES(Centro de EstudosPesquisaPrevencao e Tratamento em Saúde)Santo AndréBrazil Laboratório de Bioprospeccao e BiotecnologiaCOTI(Coordenacao de Tecnologia e Inovacao)INPA(Instituto Nacional de Pesquisas da Amazonia)ManausBrazil 

出 版 物：《Advances in Biological Chemistry》 (生物化学进展（英文）)

年 卷 期：2013年第3卷第6期

页      面：525-535页

学科分类：1002[医学-临床医学] 100214[医学-肿瘤学] 10[医学] 

基　　金：financial support from Brazilian agencies FAPESP(Fundacao de Amparo a Pesquisa do Estado de Sao Paulo) CNPq(Conselho Nacional de Pesquisa e Desenvolvimento Tecnológi-co as CT-Agro and PPBio projects)and FAPEAM(Fundacao de AmparoàPesquisa do Estado do Amazonas)and CENBAM-CNPq-MCTI(Instituto Nacional de Ciencia e Tecnologia de Estudos Integra-dos da Biodiversidade Amazonica) 

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

摘      要：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.