Evaluation of novel one-electron reduction with metal in DNA.

Indium(0) is known to work as a good one-electron reductant with a small first ionization potential. Additionally, this metal is very stable in aqueous media. Therefore, indium has a bright prospect of developing a new method for the site-selective reduction of biopolymers. In this paper, the reduction of 5-halouracils with indium in aqueous solution is reported. We prepared four halouracils, i.e., 5-fluorouracil, 5-chlorouracil, 5-bromouracil, and 5-iodouracil, and evaluated their reduction with indium in water. Incubation of 5-bromouracil and 5-iodouracil with sonication in the presence of indium efficiently caused dehalogenation to uracil. Natural nucleobases (G, A, C, T and U) were not damaged by indium under the same reaction condition.