3. Designing new ligands

The methods presented below are based on a comparative analysis of ligands (ligand-based drug design) and an analysis of the interactions between a ligand and a protein (structure-based drug design). At present, there is a logical tendency for the two methods to cross-fertilize each other, since a pharmacophore can be supplemented by data from a receptor, or even completely designed from a receptor. In the description below, we'll stick to a classic approach.