Veterinary Neuropharmacology

STRUCTURE ACTIVITY RELATIONSHIP

• Maximum sympathomimetic activity is noticed when two carbon atoms separate the aromatic ring from the amine group.
• Increased bulkiness of substitution on the N-atom increases the beta receptor activity.
• Lesser the substitution in the N-atom greater is the activity.
• Removal of one or both the OH^- groups reduces the β activity.
• Substitution of ring hydroxyl group reduces potency.
• Beta  carbon side chain substitution results in less active central actions.
• A carbon substitution gives a compound not susceptible to MAO.
• Alkyl substitution in amino group affects both alpha and beta agonist properties.

Click to view the structure activity relationship of catecholamines