A Universal, Photocleavable DNA Base:  Nitropiperonyl 2‘-Deoxyriboside

A universal, photochemically cleavable DNA base analogue would add desirable versatility to a number of methods in molecular biology. A novel C-nucleoside, nitropiperonyl deoxyriboside (NPdR, P*), has been investigated for this purpose. NPdR can be converted to its 5‘-DMTr-3‘-CE-phosphoramidite and was incorporated into pentacosanucleotides by conventional synthesis techniques. The destabilizing effect on hybrid formation with a complementary strand when this P* base opposes A, T, and G was found to be 3−5 kcal/mol, but 9 kcal/mol when it opposes C. Brief irradiation (λ > 360 nm, 20 min) of DNA containing the P* base and piperidine treatment causes strand cleavage giving the 3‘- and 5‘-phosphates. Two significant recent interests, universal/non-hydrogen-bonding base analogues and photochemical backbone cleavage, have thus been combined in a single molecule that serves as a light-based DNA scissors.