Synthesis and biological evaluation of Esaprazole analogues showing σ1 binding and neuroprotective properties in vitro

Bioorg Med Chem. 2013 Jun 1;21(11):3334-47. doi: 10.1016/j.bmc.2013.02.058. Epub 2013 Apr 2.

Abstract

Esaprazole, a molecule previously acknowledged to protect against stomach and intestinal ulcers was surprisingly discovered to have neuroprotective activities and σ1 binding in vitro. A highly diverse set of Esaprazole analogues 2-5 was prepared in order to increase blood-brain barrier penetration. The analogues showed a structure-activity relationship at the σ1 receptor closely matching already published pharmacophores. Many of the analogues were shown to have neuroprotective properties in two assays using primary cultures of cortical neurons exposed to glutamate and hydrogen peroxide. However, no apparent SAR for these two assays could be developed. Metabolic stability of the analogues were also investigated and the structure of R(1) had a significant bearing on the ADME properties of the compound resulting in two series of compounds. Compounds in which R(1) was a H or acyl group had good metabolic stability in RLM but poor BBB penetration, whereas compounds where R(1) was a cyclo- or bicyclo-alkyl group had poor metabolic stability but good BBB penetration.

MeSH terms

  • Animals
  • Anti-Ulcer Agents / chemical synthesis*
  • Anti-Ulcer Agents / chemistry
  • Anti-Ulcer Agents / pharmacology
  • Blood-Brain Barrier / metabolism
  • Capillary Permeability
  • Cerebral Cortex / cytology
  • Cerebral Cortex / drug effects*
  • Cerebral Cortex / metabolism
  • Drug Stability
  • Glutamic Acid / pharmacology
  • Hydrogen Peroxide / pharmacology
  • Neurons / cytology
  • Neurons / drug effects*
  • Neurons / metabolism
  • Neuroprotective Agents / chemical synthesis*
  • Neuroprotective Agents / chemistry
  • Neuroprotective Agents / pharmacology
  • Piperazines / chemical synthesis*
  • Piperazines / chemistry
  • Piperazines / pharmacology
  • Primary Cell Culture
  • Protein Binding
  • Radioligand Assay
  • Rats
  • Receptors, sigma / agonists
  • Receptors, sigma / metabolism*
  • Structure-Activity Relationship

Substances

  • Anti-Ulcer Agents
  • Neuroprotective Agents
  • Piperazines
  • Receptors, sigma
  • esaprazole
  • Glutamic Acid
  • Hydrogen Peroxide