Adenosine A2A receptor antagonists as novel anti-Parkinsonian agents: a review of structure-activity relationships

The adenosine A(2A) receptor (AA(2A)R) has emerged as an attractive target for the treatment of Parkinson's disease. Evidence suggests that antagonists of the AA(2A)R may be neuroprotective and may help to alleviate the symptoms of Parkinson's disease. During last decade, many efforts have been accomplished searching potent and selective AA(2A)R antagonists. In this field, various xanthines and non-xanthine heterocyclic compounds of monocyclic, bicyclic and tricyclic nucleus possessing very good affinity with a broad range of selectivity have been proposed. The aim of this article is to summarize available data on different chemical classes of AA(2A)R antagonists including those in clinical development, and briefly present an overview of the structure-activity relationships found for these compounds.