Oral Presentation The 16th Australian Peptide Conference 2025

Total Synthesis of Talarolide A Highlights the Role of Hydroxamates in Atropisomerism of Cyclic Peptides (129393)

Waleed M Hussein 1 , Angela A Salim 1 , Rob J Capon 1
  1. Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia

Using a solid-phase synthetic strategy, we report the successful total synthesis of talarolide A, a marine-derived cyclic peptide featuring a rare hydroxamate hydrogen-bond bridge. Strategic disconnection enabled the assembly of a protected linear precursor, followed by sequential deprotection and macrocyclization. We found that cyclizing the fully deprotected peptide was essential to promote correct conformational folding and achieve the natural product’s structure. This approach not only yielded talarolide A but also unveiled a non-canonical atropisomer (atrop-talarolide A), highlighting the underexplored role of hydroxamate-mediated hydrogen bonding in driving atropisomerism in non-ribosomal peptide synthetase (NRPS)-derived peptides.