Functionalized head-to-head hairpin polyamides: Synthesis, double-stranded DNA-binding activity and affinity

A series of 4 functionalized head-to-head-linked hairpin oligo(N-methylpyrrole) carboxamides with different linkers have been synthesized. Their ability to bind double-stranded DNA and sequence specificity were compared and the apparent Kd values of their DNA complexes were determined. These compounds, particularly those with iminodiacetic linkers, revealed a high affinity for DNA (Kd = 4.5–4.8 × 10−9 M) and sequence specific recognition of 9–10 base pairs.