Synthesis and Biophysical Properties of Triazole-Incorporated PMOs (TzPMOs): A Convergent, Click Ligation Approach

J Org Chem. 2024 Mar 1;89(5):2895-2903. doi: 10.1021/acs.joc.3c02242. Epub 2024 Feb 12.

Abstract

The synthesis of phosphorodiamidate morpholino oligonucleotides (PMOs) incorporating single or double triazole rings in the backbone has been achieved via Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC). The synthetic approach implemented is fundamentally convergent, involving the ligation of a 5'-azide PMO fragment to a 3'-alkyne fragment both in solution and on solid support. To access the 3'-alkyne PMO fragment, we synthesized 3'-N-propargyl chlorophosphoramidate morpholino monomers for all four nucleobases. The resulting triazole-incorporated PMOs (TzPMOs) have exhibited comparable or improved binding affinity toward complementary deoxyribonucleic acid (DNA)/ribonucleic acid (RNA) strands compared to its regular analogues. Finally, a full-length TzPMO was designed to target the Nanog gene, demonstrating almost identical hybridization properties when compared to its regular version. Circular dichroism studies revealed a B-type helical conformation for the duplexes formed by TzPMOs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkynes*
  • Azides*
  • Circular Dichroism
  • Morpholinos
  • Triazoles

Substances

  • Azides
  • Morpholinos
  • Alkynes
  • Triazoles