Synthesis, ligand binding, and quantitative structure-activity relationship study of 3 beta-(4'-substituted phenyl)-2 beta-heterocyclic tropanes: evidence for an electrostatic interaction at the 2 beta-position

J Med Chem. 1996 Jul 5;39(14):2753-63. doi: 10.1021/jm960160e.

Abstract

A set of 3 beta-(4'-substituted phenyl)-2 beta-heterocyclic tropanes was designed, synthesized, and characterized. We discovered that these compounds can function as bioisosteric replacements for the corresponding WIN 35,065-2 analogs which possess a 2 beta-carbomethoxy group. Several of the compounds showed high affinity and selectivity for the dopamine transporter (DAT) relative to the serotonin and norepinephrine transporters. From the structure-activity relationship study, the 3 beta-(4'-chlorophenyl)-2 beta-(3'-phenylisoxazol-5-yl)tropane (5d) emerged as the most potent and selective compound. The binding data for 2 beta-heterocyclic tropanes were found to show a high correlation with molecular electrostatic potential (MEP) minima near one of the heteroatoms in the 2 beta-substituents. In contrast, low correlations were found for other MEP minima near the 2 beta-substituent as well as for calculated log P or substituent volume. These quantitative structure-activity relationship studies are consistent with an electrostatic contribution to the binding potency of these WIN 35,065-2 analogs at the DAT.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Binding Sites
  • Binding, Competitive
  • Carrier Proteins / metabolism
  • Cocaine / analogs & derivatives*
  • Cocaine / chemical synthesis
  • Cocaine / metabolism
  • Dopamine Plasma Membrane Transport Proteins
  • Ligands
  • Membrane Glycoproteins*
  • Membrane Transport Proteins*
  • Models, Molecular
  • Nerve Tissue Proteins*
  • Rats
  • Structure-Activity Relationship

Substances

  • Carrier Proteins
  • Dopamine Plasma Membrane Transport Proteins
  • Ligands
  • Membrane Glycoproteins
  • Membrane Transport Proteins
  • Nerve Tissue Proteins
  • Slc6a3 protein, rat
  • troparil
  • Cocaine