Problem
In guanosine, protonation of N7 promotes hydrolysis of the glycosidic bond due to delocalization of the positive charge. Similarly, protonation of N3 in cytidine also promotes hydrolysis of the glycosidic bond.
1. Draw the resonance structure of cytidine that places the positive charge on N1.
2. In double-stranded DNA, G residues are much more sensitive to acid catalyzed hydrolysis of the glycosidic bond than are C residues. Why should this be the case?