Figure 1.

(Top) G-quartet (Left) and an intramolecular quadruplex (Right). The 5′ fluorescein and 3′ tetramethylrhodamine groups are depicted by dark gray and light gray ovals, respectively. (Middle) List of the oligonucleotides used in the present study. Abbreviations used for the fluorescent oligonucleotide are indicated, with the following convention: the dye is written first if it is linked to the 5′ end of the oligonucleotide; when linked to the 3′ end, it is written last. fluo: fluorescein; tamra: tetramethylrhodamine. (Bottom) Chemical formula of dibenzophenanthroline derivatives tested as G4 ligands.