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 (ε·φ) 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.