Using a pharmacophore representation concept to elucidate molecular similarity of dopamine antagonists

The pharmacophoric concept plays an important role in ligand-based drug design methods to describe the similarity and diversity of molecules, and could also be exploited as a molecular representation scheme. A three-point pharmacophore method was used as a molecular representation perception. This procedure was implemented for dopamine antagonists of the D-2 receptor subtype. The molecular structures of the antagonists included in this analysis were categorized into two structurally distinct classes. Using structural superposition with internal energy minimization, two pharmacophore models were deduced. Based on these two models other D-2 antagonists that fulfil them were derived and studied. This procedure aided the identification of the common 3D patterns present in diverse molecules that act at the same biological target and the extraction of a common molecular framework for the two structural classes. The pharmacophoric information was found to be suitable for guiding superposition of structurally diverse molecules, using a more biologically meaningful selection of the targeting points.