Rational Design, Synthesis, and Pharmacological Characterization of Novel Ghrelin Receptor Inverse Agonists as Potential Treatment against Obesity-Related Metabolic Diseases

J Med Chem. 2018 Dec 27;61(24):11039-11060. doi: 10.1021/acs.jmedchem.8b00794. Epub 2018 Oct 15.

Abstract

A new chemotype of ghrelin inverse agonists was discovered through chimeric design based on molecular scaffolds known as growth-hormone secretagogue receptor (GHSR) modulators but with divergent pharmacodynamic and pharmacokinetic properties. The structure-activities/properties exploration led to compound 47, which displayed potent human GHSR antagonism and inverse agonism in cellular assays (IC50 = 68 nM, EC50 = 29 nM), moderate oral bioavailability, and notable brain penetration in rat ( F = 27%, B/ P ratio = 1.9). First in vivo studies demonstrated effective reduction of food intake after oral or parenteral administration to mouse (78% at 1 h and 38% at 8 h, respectively). Further preclinical studies are needed to evaluate the most suited mode of administration with the aim of promoting a first central-acting ghrelin inverse agonist molecule to development, which would represent a significant step toward therapeutic agents to treat metabolic disorders related to obesity, such as type 2 diabetes mellitus.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Alkynes / administration & dosage
  • Alkynes / chemical synthesis*
  • Alkynes / pharmacology
  • Animals
  • Biological Availability
  • Brain / drug effects
  • Brain / metabolism
  • Cyclopropanes / administration & dosage
  • Cyclopropanes / chemical synthesis*
  • Cyclopropanes / pharmacology
  • Dogs
  • ERG1 Potassium Channel / antagonists & inhibitors
  • Eating / drug effects
  • Humans
  • Male
  • Metabolic Diseases / drug therapy*
  • Mice, Inbred C57BL
  • Microsomes, Liver / drug effects
  • Molecular Docking Simulation
  • Obesity / complications*
  • Obesity / metabolism
  • Piperidines / administration & dosage
  • Piperidines / chemical synthesis*
  • Piperidines / pharmacology
  • Rats
  • Receptors, Ghrelin / agonists*
  • Receptors, Ghrelin / antagonists & inhibitors
  • Receptors, Ghrelin / chemistry
  • Stereoisomerism
  • Structure-Activity Relationship

Substances

  • Alkynes
  • Cyclopropanes
  • ERG1 Potassium Channel
  • Ghsr1a protein, human
  • KCNH2 protein, human
  • Piperidines
  • Receptors, Ghrelin