The Role of dihydropyrazines in accelerated death of Escherichia coli on addition of copper(II)

Dihydropyrazines (DHPs), which are derived from sugars, inhibit the growth of Escherichia coli. Addition of copper(II) ion (Cu2+) accelerates the effect of DHPs, resulting in cell death. Investigation of the lethal effect in several DNA repair-deficient or detoxifying enzyme-deficient mutant strains and radical scavengers suggested that the cytotoxic and genotoxic damage was caused by radical species (hydroxyl, superoxide anion, and carbon-centered radicals) generated from reaction of DHPs with Cu2+.