DNA containing phenanthroline- and phenanthrene-derived, non-nucleosidic base surrogates

Simple, non-nucleosidic phenanthroline- and phenanthrene derivatives have been synthesised and incorporated into oligodeoxynucleotides. Complementary strands containing the modified building blocks in opposite positions form stable hybrids. Thermal denaturation experiments show that the double strands containing the phenanthroline derivatives are more stable than the ones with the corresponding phenanthrenes. Furthermore, it was found that duplex stability is considerably decreased if the linkers of the modified building blocks are too short.