Synthesis and properties of chiral peptide nucleic acids with a N-aminoethyl-D-proline backbone

A synthon of D-proline substituted at the 4-position by thymine and at N by a flexible aminoethyl linker, has been used to prepare a novel chiral peptide nucleic acid (cPNA) with (2R,4R) stereochemistry using solid phase methodology. The homothymine decamer cPNA binds to complementary polyadenylic acid to form a 2:1 hybrid with high affinity and specificity according to UV and CD studies, whereas no binding to the corresponding polydeoxyadenylic acid was observed.