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Spectrophotometrical Study of Antioxidant Standards Interacting with 2,2-Diphenyl-1-Picrylhydrazyl Radical

This work aims to study the interaction of four well known antioxidant standards with 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•) using spectrophotometric assays. The binding parameters like binding constant and binding free energy of the free and DPPH• bound forms were determined. The determination is based upon the decrease in absorbance of the electronic absorption spectrum of an acetonitrile solution of DPPH• in the presence of gradually increasing amount of antioxidant standards.