Dibenzotetraaza[14]annulene–adenine conjugate recognizes complementary poly dT among ss-DNA/ss-RNA sequences

Among three novel DBTAA derivatives only the DBTAA–propyl–adenine conjugate 1 showed recognition of the consecutive oligo dT sequence by increased affinity and specific induced chirooptical response in comparison to other single stranded RNA and DNA; whereby of particular importance is the up until now unique efficient differentiation between dT and rU. At variance, its close analogue DBTAA–hexyl–adenine 2 did not reveal any selectivity between ss-DNA/RNA pointing out the important role of steric factors (linker length); moreover non-selectivity of the reference compound (3, lacking adenine) stressed the importance of adenine interactions in the 1 selectivity.