Solid-phase synthesis and properties of chiral peptide nucleic acids bearing cationic side chains

Abstract

A novel chiral peptide nucleic acid, ornithine-based nucleobase-linked polyamide (ONA), aimed to hybrid with a DNA duplex to form triplexes, was designed and synthesized. The chiral monomers composed of the ornithine-based backbone and the serine-derived side chains were synthesized in stereocontrolled manners. The diastereopure oligomers were synthesized by a solid-phase method using the diastereopure monomers. Highly cross-linked polystyrene (HCP) resin was employed as a solid support to minimize the aggregation of the oligomer which was suspected to occur during the chain elongation. By the use of new solid-phase method, homo-thymine ONA oligomers were synthesized in good yields. The ONA hexamer was found to form a triplex with the dsDNA in a sequence specific manner.