Photoinduced DNA Cleavage via Electron Transfer: Demonstration That Guanine Residues Located 5′ to Guanine Are the Most Electron-Donating Sites

摘要

Electron transfer from a -GG- step in duplex DNA to triplet excited 1 was demonstrated for the first time by direct observation of the electron transfer intermediate. While the electron loss center created in DNA has long been known to ultimately end up at guanine due to its lowest ionization potential among the nucleobases, the present studies indicate that the most electron-donating sites in duplex DNA are the guanine residues located 5′ to guanine.