Marked metal ion effects in electron transfer from reduced flavin to aromatic nitro compounds in ethanol

Abstract

The reduction of p-chloronitrobenzene by a reduced flavin has been investigated kinetically in the presence of divalent metal ions in EtOH under anaerobic conditions. A large rate acceleration due to the metal ions was observed; 1(none):32(Zn²⁺):420 (Ni²⁺):1 000(Co²⁺):12 (Mn²⁺). The role of the metal ions is proposed. The reducing ability of metal-chelated flavin radicals has been briefly examined by employing 2,4-dinitrochlorobenzene as an electron acceptor.