Multivalent Interactions between an Aromatic Helical Foldamer and a DNA G-Quadruplex in the Solid State

Quinoline-based oligoamide foldamers have been identified as a potent class of ligands for G-quadruplex DNA. Their helical structure is thought to target G-quadruplex loops or grooves and not G-tetrads. We report a co-crystal structure of the antiparallel hairpin dimeric DNA G-quadruplex (G(4)T(4)G(4))(2) with tetramer 1a helically folded oligo-quinolinecarboxamide bearing cationic side chainsthat is consistent with this hypothesis. Multivalent foldamer-DNA interactions that modify the packing of (G(4)T(4)G(4))(2) in the solid state are observed