Open AccessStopped-Flow Spectrophotometric Studies of the Kinetics of Interaction of Dihydroxyfumaric Acid with the DPPH Free Radical
Author(s) -
Natalia Secara
Publication year - 2010
Publication title -
chemistry journal of moldova
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.275
H-Index - 5
eISSN - 2345-1688
pISSN - 1857-1727
DOI - 10.19261/cjm.2010.05(2).11
Subject(s) - chemistry , kinetics , dpph , stoichiometry , reaction rate constant , reaction rate , order of reaction , chemical kinetics , medicinal chemistry , catalysis , photochemistry , organic chemistry , antioxidant , physics , quantum mechanics
The reaction of dihydroxyfumaric acid with the free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) was studied using the stopped-flow method, in order to describe the reaction kinetics. Dihydroxyfumaric acid reacts very rapidly with DPPH, the reaction being completed in several minutes. This 2-stoichiometric reaction proceeds in two stages, with reaction orders of 1 and 0.76 with respect to DPPH, and 0.5 and 0.3 with respect to DHF, respectively. The rate constant of the two stages of the reaction were found to be 39.1 (L/mol•s) and 0.0012 (s-1) at 20º C and pH 4.0.