Dual acting antioxidant A1 adenosine receptor agonists

Herein we report the synthesis and biological evaluation of some potent and selective A1 adenosine receptor agonists, which incorporate a functionalised linker attached to an antioxidant moiety. N6-(2,2,5,5-Tetramethylpyrrolidin-1-yloxyl-3-ylmethyl)adenosine (VCP28, 2e) proved to be an agonist with high affinity (Ki = 50 nM) and good selectivity (A3/A1 ⩾ 400) for the A1 adenosine receptor. N6-[4-[2-[1,1,3,3-Tetramethylisoindolin-2-yloxyl-5-amido]ethyl]phenyl]adenosine (VCP102, 5a) has higher binding affinity (Ki = 7 nM), but lower selectivity (A3/A1 = ∼3). All compounds bind weakly (Ki > 1 μM) to A2A and A2B receptors. The combination of A1 agonist activity and antioxidant activity has the potential to produce cardioprotective effects.

Graphical abstractHerein we report the synthesis and biological evaluation of some potent and selective A1 adenosine receptor agonists, which incorporate a functionalised linker attached to an antioxidant moiety. N6-(2,2,5,5-Tetramethylpyrrolidin-1-yloxyl-3-ylmethyl)adenosine (VCP28, 2e) proved to be an agonist with high affinity (Ki = 50 nM) and good selectivity (A3/A1 ⩾ 400) for the A1AR. N6-[4-[2-[1,1,3,3-Tetramethylisoindolin-2-yloxyl-5-amido]ethyl]phenyl]adenosine (VCP102, 5a) has higher binding affinity (Ki = 7 nM), but lower selectivity (A3/A1 = ∼3). All compounds bind weakly (Ki > 1 μM) to A2A and A2B receptors. The combination of A1 agonist activity and antioxidant activity has the potential to produce cardioprotective effects.Figure optionsDownload full-size imageDownload as PowerPoint slide