Structure-Based Optimization of Coumarin hA₃ Adenosine Receptor Antagonists

Area of Science:

• Medicinal Chemistry
• Pharmacology
• Drug Discovery

Background:

• Adenosine receptors play crucial roles in various physiological processes.
• Selective ligands for adenosine receptors are valuable for disease treatment.
• 3-Arylcoumarins have demonstrated neuroprotective properties.

Purpose of the Study:

• To investigate 8-substituted 3-arylcoumarins as ligands for adenosine receptors.
• To identify selective adenosine receptor antagonists.
• To explore the potential of this scaffold for multitarget drug development.

Main Methods:

• Synthesis of novel 8-substituted 3-arylcoumarins.
• Radioligand binding assays to evaluate receptor interaction.
• X-ray diffraction analysis for structural elucidation.
• Theoretical modeling for data corroboration.

Main Results:

• Several selective A3 receptor antagonists were identified among the synthesized compounds.
• Compound 4 (3-(4-Bromophenyl)-8-hydroxycoumarin) exhibited the highest potency and selectivity (Ki = 258 nM) for the A3 receptor.
• Structure-activity relationship analysis revealed the importance of substituent nature and position.

Conclusions:

• The novel 3-arylcoumarin scaffold is a promising starting point for developing selective adenosine receptor antagonists.
• Understanding structure-activity relationships guides the design of potent and selective compounds.
• This scaffold holds potential for generating candidates for multitarget drug therapies.