Synthesis of 3'-ureidoadenosines and their high binding affinity at the mutant A3 adenosine receptor.

For the purpose of developing optimal neoceptor-neoagonist pair, 3'-ureidoadenosine derivatives were synthesized. Among compounds tested, 2-chloro-3'-ureido-N6-(3-iodobenzyl)adenosine (10b) showed the best binding affinity (Ki = 0.20 microM) at the H272E mutant A3 AR, but was inactive at the natural A3 AR.