STIMULATION BY COPPER(II) OF REACTIVITY OF VARIOUS SULFHYDRYL-CONTAINING COMPOUNDS WITH 2,2-DIPHENYL-1-PICRYLHYDRAZYL

Abstract

The reaction of 2,2-diphenyl-1-picrylhydrazyl (DPPH) with various sulfhydryl-containing compounds including ergothioneine, glutathione, 1-methyl-2-mercaptoimidazole (methimazole), and 2-mercaptoimidazole was stimulated 7-14 fold by the addition of copper (II) sulfate. The reaction of DPPH with other 2-imidazolethiones substituted at both the 4 and 5 positions was not stimulated by Cu(II). The stimulation may result from the formation of a complex between Cu(II) and the sulfhydryl-containing compounds.

Key Words:

• 2,2-diphenyl-1-picrylhydrazyl
• Cu(II)
• sulfhydryl
• 2-imidazolethione
• radical
• antioxidant