Amino/guanidino-functionalized N-(pyrrolidin-2-ethyl)glycine-based pet-PNA: Design, synthesis and binding with DNA/RNAElectronic supplementary information (ESI) available: 1H, 13C NMR and mass spectral data for all new compounds, HPLC and MALDI-TOF of PNA sequences and UV-Tm studies of all the complexes. See DOI: 10.1039/c004005c

The N -(pyrrolidin-2-ethyl) glycine-based PNA (pet-PNA) backbone, with 4-amino or 4-guanidino-functionalized pyrrolidine ring, confers constrained conformational flexibility on aegPNA. The oligomers bind to the target DNA and RNA sequences with increased sequence specificity and antiparallel versus parallel orientation selectivity. The easy post-synthetic guanidination gives very good access to the positively charged PNA oligomers. One atom extended, chiral, amino/guanidino functionalized pyrrolidin-2-ethyl PNA, pet-PNA, allows sequence specific and orientation selective binding to target DNA/RNA in either duplex or triplex modes.