Pyrrolidyl polyamines: branched, chiral polyamine analogues that stabilize DNA duplexes and triplexes

[figure: see text] Pyrrolidyl polyamines (III-VI) are conformationally restricted, chiral analogues of linear spermine elaborated by the addition of aminopropyl chains to yield branched diastereomers. It is demonstrated that in concentrations as low as 0.01 mM, these compounds remarkably stabilize DNA duplexes and triplexes through strong electrostatic interactions. The synthesized compounds are potential dendrons with a chiral pyrrolidine core, and such molecules may have potential as DNA delivery and transfection agents.