Steric aspects of dopaminergic drugs

There are a variety of molecule species of dopamine avaialable at physiological pH. The predominant form available at physiological pH is the phenolic ammonium salt. However, at the present time the molecular form that is optimum for producing dopaminergic activity is unknown. In attempting to delineate the conformational requirements of dopaminergic agonists, a variety of conformationally restricted analogs and complex molecules possessing a dopaminergic segment have been investigated. It appears at this time that the trans extended form of dopamine is the optimum form for binding to dopamine receptors. The rotameric forms of dopamine are also important considerations when examining a molecule for dopaminergic agonist activity. A high degree of stereospecificity has been shown in different dopaminergic systems.