Design, Synthesis, Properties, and Applications of Chiral Peptide Nucleic Acid Monomers

Peptide nucleic acids (PNAs) are synthetic nucleic acid mimics wherein the sugarphosphate backbone is replaced with a peptide backbone. PNAs hybridize to complementary DNA and RNA with higher affinity and superior sequence selectivity compared with DNA. An important consideration when using PNAs is the possibility of adjusting their chirality in a controlled manner using PNA monomers. The chirality of PNAs plays a major role in their ability to recognize their complementary DNA because of the intrinsically chiral character of the DNA structure. The asymmetry generated and amplified in PNAs can also be transferred to other residues, including dyes for non-linear optics and reactive species for catalysis or template synthesis, thereby paving the way to other technological applications. However, despite the increasing number of reports published thus far, no full review has yet been conducted on chiral PNA monomers. This review focuses on state-of-the-art research on the design, synthesis, properties, and applications of chiral PNA monomers. Some perspectives on future development are also raised.