Fluorescence switching of photochromic vinylpyrene-substituted 2′-deoxyguanosine

We synthesized C8-vinylpyrene-substituted 2′-deoxyguanosine VPyG and studied the photoregulated reversible E–Z isomerization. When E-isomer was irradiated with visible light (>420 nm), E- to Z-isomerization took place very rapidly, while upon irradiation with UV-light (∼365 nm), Z-isomer was converted to E-isomer. When Z-isomer was illuminated with 365–400 nm light, no fluorescence was observed, while E-isomer showed a very strong fluorescence emission, indicating that VPyG could be a useful fluorescence switching molecule.