Synthesis and DNA binding properties of dioxime–peptide nucleic acids

Peptide nucleic acids (PNAs) C- or N-modified with dioxime ligands were prepared by solid-phase synthesis using iron(II)-clathrochelates as protected dioxime building blocks. These PNA bind complementary DNA sequence specifically, though with much reduced affinity in comparison with nonmodified PNA. The dioxime–PNA conjugates bind Cu2+ and Ni2+ at μM concentration.