Independent Photochemical Generation and Reactivity of Nitrogen-Centered Purine Nucleoside Radicals from Hydrazines

Article abstract of DOI:10.1021/acs.orglett.7b03368

Photochemical precursors that produce dA^￠ and dG(N₂-H)^￠ are needed to investigate their reactivity. The synthesis of two 1,1-diphenylhydrazines (1, 2) and their use as photochemical sources of dA^￠ and dG(N₂-H)^￠ is presented. Trapping studies indicate production of these radicals with good fidelity, and 1 was incorporated into an oligonucleotide via solid-phase synthesis. Cyclic voltammetric studies show that reduction potentials of 1 and 2 are lower than those of widely used "hole sinks", e.g., 8-oxodGuo and 7-deazadGuo, to investigate DNA-hole transfer processes. These molecules could be useful (a) as sources of dA^￠ and dG(N₂-H)^￠ at specific sites in oligonucleotides and (b) as "hole sinks" for the study of DNA-hole transfer processes.