Characterization of 2‐Fluoro‐2’‐deoxyadenosine in Duplex, G‐Quadruplex and i‐Motif

Abstract Among various kinds of fluorine‐substituted biomolecules, 2‐fluoroadenine (2FA) and its derivatives have been actively investigated as therapeutic reagents, radio‐sensitizers, and 19 F NMR probes. In spite of their excellent properties, DNA containing 2FA has not been studied well. For fundamental understanding and future applications to the development of functional nucleic acids, we characterized 2FA‐containing oligonucleotides for canonical right‐handed DNA duplex, G‐quadruplex, and i‐motif structures. Properties of 2FA were similar to native adenine due to the small size of the fluorine atom, but it showed unique features caused by high electronegativity. This work provides useful information for future application of 2FA‐modified DNA.