Adrenergic agonists' structure-activity relationship (SAR) determines their selectivity and efficacy. These agonists comprise a phenylethylamine moiety with an aromatic ring and an ethylamine side chain.
Aromatic ring substitutions: Substituting the aromatic ring with –OH groups at positions 3 and 4 yields catecholamines (e.g., epinephrine), which have a high affinity for adrenoceptors. Hydrogen bonding between –OH groups and receptors enhances adrenergic activity.
Separation of the aromatic ring and amino group: A two-carbon chain optimally separates the amino group from the ring, as seen in norepinephrine and epinephrine.
Substitutions on the amino, α, and β-carbon: Modifications on the amino group and α-carbon affect potency, selectivity, and duration of action. α-methyl substitution increases α1-receptor selectivity. Substituting the amino group with a bulkier alkyl group increases β2-selectivity.
Optical Isomerism: Optical isomers of adrenergic agonists have different pharmacological properties. Levorotatory β-hydroxyl and dextrorotatory α-methyl substitutions exhibit maximum agonist potency.
Understanding the SAR of adrenergic agonists is crucial for developing targeted and effective medications with specific receptor affinity and selectivity.
From Chapter 6:
Now Playing
Drugs Acting on Autonomic Nervous System: Adrenergic Agonists and Antagonists Agents
2.3K Views
Drugs Acting on Autonomic Nervous System: Adrenergic Agonists and Antagonists Agents
3.0K Views
Drugs Acting on Autonomic Nervous System: Adrenergic Agonists and Antagonists Agents
1.8K Views
Drugs Acting on Autonomic Nervous System: Adrenergic Agonists and Antagonists Agents
1.2K Views
Drugs Acting on Autonomic Nervous System: Adrenergic Agonists and Antagonists Agents
1.3K Views
Drugs Acting on Autonomic Nervous System: Adrenergic Agonists and Antagonists Agents
1.1K Views
Drugs Acting on Autonomic Nervous System: Adrenergic Agonists and Antagonists Agents
1.3K Views
Drugs Acting on Autonomic Nervous System: Adrenergic Agonists and Antagonists Agents
528 Views
Drugs Acting on Autonomic Nervous System: Adrenergic Agonists and Antagonists Agents
520 Views
Drugs Acting on Autonomic Nervous System: Adrenergic Agonists and Antagonists Agents
598 Views
Drugs Acting on Autonomic Nervous System: Adrenergic Agonists and Antagonists Agents
664 Views
Drugs Acting on Autonomic Nervous System: Adrenergic Agonists and Antagonists Agents
425 Views
Drugs Acting on Autonomic Nervous System: Adrenergic Agonists and Antagonists Agents
399 Views
Drugs Acting on Autonomic Nervous System: Adrenergic Agonists and Antagonists Agents
415 Views
Drugs Acting on Autonomic Nervous System: Adrenergic Agonists and Antagonists Agents
319 Views
See More
Copyright © 2025 MyJoVE Corporation. All rights reserved