Development of analytical methodology for the determination of antioxidant capacity of plant extracts exploiting the Cu (II)/4,4'-dicarboxy-2,2'-biquinoline complexes

• Grant number: 13/08496-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: May 01, 2013
• End date: April 30, 2014
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Analytical Chemistry
• Principal Investigator: Horacio Dorigan Moya
• Grantee: Hariane Rezende Manoel
• Host Institution: Faculdade de Medicina do ABC (FMABC). Santo André , SP, Brazil

Abstract

The aim of this project is the development of a spectrophotometric method for the determination of the total antioxidant capacity of aqueous plant extracts, based on the reduction of Cu (II) to Cu (I) in medium buffer (pH 7.0, ammonium acetate) containing 4,4 '-carboxy-2, 2'-quinoline acid. The plant extracts are rich in antioxidants and the addition of aliquots of these extracts in a solution containing Cu (II) and BCA promotes the formation of Cu(I)/BCA. In order to calculate the antioxidant capacity values of these plant extracts, the absorbance values of Cu(I)/BCA will be compared with the values of absorbance of an ascorbic acid solution, which is considered a standard antioxidant. In the next step, the individual antioxidant capacity of several polyphenols standard solutions (phenolic acids such as gallic acid, and flavonoids such as quercetin) will be evaluated with the same reaction used in this proposed method. This study will clarify how the structure and type of radical attached to the benzene group contribute to the antioxidant capacity of each polyphenol. Besides, it may be also evaluated the influence of the number and position of hydroxyl groups present on each polyphenol, since it is well known that the presence of these groups is strongly responsible for the antioxidant properties of these compounds. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

MANOEL, HARIANE R.; MOYA, HORACIO D.. A Comprehensive Study of the Use of Cu(I)/4,4 `-Dicarboxy-2,2 `-biquinoline Complexes to Measure the Total Reducing Capacity: Application in Herbal Extracts. Molecules, v. 20, n. 12, p. 22411-22421, DEC 2015. (13/08496-5)

MANOEL, HARIANE R.; MOYA, HORACIO D.. A Comprehensive Study of the Use of Cu(I)/4,4 '-Dicarboxy-2,2 '-biquinoline Complexes to Measure the Total Reducing Capacity: Application in Herbal Extracts. Molecules, v. 20, n. 12, p. 11-pg., 2015-12-01. (13/08496-5)