Recent developments in the field of A(2A) and A(3) adenosine receptor antagonists

A review. In the last years adenosine receptors have been extensively studied, and mainly at present the importance of A2A and A3 adenosine receptors is understood. A2A selective adenosine receptors antagonists are promising new drugs for the treatment of Parkinson's disease, while A3 selective adenosine receptors antagonists have been postulated as novel anti-inflammatory and antiallergic agents; recent studies also indicated a possible employment of these derivs. as antitumor agents. Lately different classes of compds. have been identified as potent A2A and A3 antagonists. In this article we report the past and present efforts which led to development of more potent and selective A2A and A3 antagonists. This research group has mainly worked on the pyrazolo[4,3-e]-1,2,4-triazolo[1,5-c]pyrimidine nucleus both as A2A and A3 antagonists, aiming to improve the affinity, selectivity and the hydrophilic profile. In fact, several compds. endowed with high affinity and selectivity vs. A2A adenosine receptors or A3 adenosine receptors were synthesized