Figure 7.

The structures of (A) RNA; (B) p-RNA; (C) TNA; (D) GNA; (E) PNA; (F) ANA; (G) diaminotriazine-tagged (left) and dioxo-5-aminopyrimidine-tagged (right) oligodipeptides; and (H) tPNA. ANA contains a backbone of alternating d- and l-alanine subunits. The diaminotriazine tags are shown linked to a backbone of alternating l-aspartate and l-glutamate subunits; the dioxo-5-aminopyrimidine tags (shown unattached) can be linked similarly. tPNA is shown with a backbone of alternating l-cysteine and l-glutamate subunits.