Laboratorium für Organische und Bioorganische Chemie, Institut für Chemie, Universität Osnabrück, Barbarastraße 7, D-49069 Osnabrück, Germany
Center for Nanotechnology, Gievenbecker Weg 11, 48149 Münster, Germany
Abstract:
Parallel stranded (ps) duplexes were constructed by incorporating 7-deaza-2′-deoxyisoguanosine (1a) or its 7-halogenated analogs 1b,c in place of 2′-deoxyisoguanosine. UV and Tm analyses prove the high affinity of ethidium bromide (EB) to these modified duplexes. Steady-state fluorescence measurement shows that the fluorescence is quenched when EB is bound to ps duplexes containing compounds 1a–c. The quenching effect depends on the 7-substituent of the nucleobase.