Ligand design for alpha, adrenoceptors

An area of continuing interest in medicinal chemistry is the design, synthesis and pharmacological evaluation of ligands which bind at adrenoceptor subtypes, which include alpha (1A), alpha (1B), alpha (1D); alpha (2A), alpha (2B), alpha (2C); beta (1), beta (2), beta (3) and possibly beta (4) subtypes. The selective blockade or stimulation of these receptor subtypes is of on-going pharmacological and medicinal interest. However, the design principles for ligand differentiation at these subtypes still need further development. This review focuses on al adrenoceptors with a concentration on literature over the past five years. Structural, physiological and therapeutic aspects of the alpha (1A), alpha (1B) and alpha (1D) subtypes are discussed together with ligands binding to these receptor subtypes. Approaches to al adrenoceptor ligand design based on known ligands and on receptor docking are evaluated. A new combined approach using pharmacophores and receptor docking affords possibilities for deeper insights into achieving small molecule binding selectivity.