Small molecule crystallography in drug design

Crystal structures of small molecules (i.e. isolated ligands) are a source of valuable structural information helpful in the process of drug design (p harmacophore model elaborations, 3D QSAR, docking, and de novo design). Ind eed, structural data obtained from small molecules crystallography can appr oach ligand-receptor binding by providing unique structural features both a bout the conformation (internal geometry) of the ligand(s) and about the in termolecular interaction potentially occurring within the active site of a target (enzyme/receptor). Small molecule crystal structure databases can al so be used in three dimensional search to identify new drug candidates. Fut ure development in small molecule crystallography (e.g. powder diffraction) should also provide original solutions to complex problems related to poly morphism.