Synthesis of xanthines as adenosine antagonists, a practical quantitative structure-activity relationship application

Area of Science:

• Medicinal Chemistry
• Pharmacology
• Computational Chemistry

Background:

• Adenosine receptors play crucial roles in various physiological processes.
• 8-Phenylxanthines are a known class of compounds with adenosine receptor antagonist properties.
• Understanding structure-activity relationships is key to designing effective drug candidates.

Purpose of the Study:

• To analyze the quantitative structure-activity relationship (QSAR) of 8-phenylxanthines for adenosine A1 receptor affinity.
• To guide the synthesis of novel compounds with improved properties.
• To investigate the impact of structural modifications on receptor binding and aqueous solubility.

Main Methods:

• Quantitative structure-activity relationship (QSAR) analysis of 56 8-phenylxanthine compounds.
• Synthesis of 20 new sulfonamide derivatives.
• In vitro testing for adenosine receptor antagonism and aqueous solubility.

Main Results:

• QSAR analysis indicated that the most potent adenosine A1 receptor binders were already synthesized.
• Phenyl substitution at the ortho position had a greater impact on potency than para substitution.
• Newly synthesized sulfonamide derivatives maintained high potency and exhibited significantly increased aqueous solubility.
• In vitro studies confirmed the antagonism of adenosine receptor-mediated physiological effects.

Conclusions:

• Further synthesis of 8-phenylxanthines with additional phenyl substituents to increase potency is not recommended.
• Para-substituted sulfonamide derivatives represent a promising strategy for developing potent and soluble adenosine receptor antagonists.
• The developed QSAR model effectively predicted the properties of novel compounds, facilitating rational drug design.