Coumarin-Caged dG for Improved Wavelength-Selective Uncaging of DNA

Herein we report on diethylaminocoumarin (DEACM) as a new photoremovable protecting group for 2'-deoxyguanosine in oligonucleotides. An oligonucleotide with O-6-DEACM-caged dG was synthesized and photochemically analyzed. The DEACM group shows superior photochemical properties at 405 nm with an uncaging efficiency (epsilon . phi) for deprotection that Is 17 times higher than that for 2-(o-nitrophenyl)-propyl NPP caging groups in the same position. Wavelength-selective deprotection in the presence of NPP groups proceeds up to 80 times faster.