Increased Potency and Selectivity for Group III Metabotropic Glutamate Receptor Agonists Binding at Dual sites

J Med Chem. 2018 Mar 8;61(5):1969-1989. doi: 10.1021/acs.jmedchem.7b01438. Epub 2018 Feb 14.


A group III metabotropic glutamate (mGlu) receptor agonist (PCEP) was identified by virtual HTS. This orthosteric ligand is composed by an l-AP4-derived fragment that mimics glutamate and a chain that binds into a neighboring pocket, offering possibilities to improve affinity and selectivity. Herein we describe a series of derivatives where the distal chain is replaced by an aromatic or heteroaromatic group. Potent agonists were identified, including some with a mGlu4 subtype preference, e.g., 17m (LSP1-2111) and 16g (LSP4-2022). Molecular modeling suggests that aromatic functional groups may bind at either one of the two chloride regulatory sites. These agonists may thus be considered as particular bitopic/dualsteric ligands. 17m was shown to reduce GABAergic synaptic transmission at striatopallidal synapses. We now demonstrate its inhibitory effect at glutamatergic parallel fiber-Purkinje cell synapses in the cerebellar cortex. Although these ligands have physicochemical properties that are markedly different from typical CNS drugs, they hold significant therapeutic potential.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aminobutyrates / pharmacology
  • Animals
  • Binding Sites*
  • Glutamic Acid / chemistry
  • Humans
  • Ligands
  • Models, Molecular
  • Molecular Mimicry
  • Phosphinic Acids / pharmacology
  • Purkinje Cells / ultrastructure
  • Receptors, Metabotropic Glutamate / agonists*
  • Synapses / drug effects
  • Synaptic Transmission / drug effects


  • Aminobutyrates
  • LSP1 2111
  • LSP4-2022
  • Ligands
  • Phosphinic Acids
  • Receptors, Metabotropic Glutamate
  • Glutamic Acid