W-shape nucleic acid (WNA) for selective formation of non-natural anti-parallel triplex including a TA interrupting site

Novel nucleoside analogs have been designed for selective formation of anti-parallel triplexes including a TA or a CG interrupting site. The new compounds are constructed of a W-shape bicyclic nucleic acid (WNA) bearing an aromatic ring as a stacking motif and a guanine for the formation of Hoogesteen hydrogen bonds, and are expected to effect triplex stabilization by both stacking and complementary hydrogen bonds. Purine-rich triplex-forming oligodeoxynucleotide (TFO) incorporating the new analog, WNA-7βG, formed a stable triplex with high selectivity to the TA site.