Structure-activity relationship of novel macrocyclic biased apelin receptor agonists

Org Biomol Chem. 2017 Jan 4;15(2):449-458. doi: 10.1039/c6ob02247b.


Apelin is the endogenous ligand for the G protein-coupled receptor APJ and exerts a key role in regulating cardiovascular functions. We report herein a novel series of macrocyclic analogues of apelin-13 in which the N- and C-terminal residues as well as the macrocycle composition were chemically modified to modulate structure-activity relationships on the APJ receptor. To this end, the binding affinity and the ability to engage G protein-dependent and G protein-independent signalling pathways of the resulting analogues were assessed. In this series, the position and the nature of the C-terminal aromatic residue is a determinant for APJ interaction and β-arrestin recruitment, as previously demonstrated for linear apelin-13 derivatives. We finally discovered compounds 1, 4, 11 and 15, four potent G protein-biased apelin receptor agonists exhibiting affinity in the nanomolar range for APJ. These macrocyclic compounds represent very useful pharmacological tools to explore the therapeutic potential of the apelinergic system.

MeSH terms

  • Animals
  • Apelin Receptors / agonists*
  • Blood Pressure / drug effects
  • Dose-Response Relationship, Drug
  • Intercellular Signaling Peptides and Proteins / chemical synthesis
  • Intercellular Signaling Peptides and Proteins / chemistry
  • Intercellular Signaling Peptides and Proteins / pharmacology*
  • Macrocyclic Compounds / chemical synthesis
  • Macrocyclic Compounds / chemistry
  • Macrocyclic Compounds / pharmacology*
  • Male
  • Molecular Conformation
  • Rats
  • Rats, Sprague-Dawley
  • Structure-Activity Relationship


  • Apelin Receptors
  • Aplnr protein, rat
  • Intercellular Signaling Peptides and Proteins
  • Macrocyclic Compounds
  • apelin-13 peptide