Novel 8-(furan-2-yl)-3-benzyl thiazolo [5,4-e][1,2,4] triazolo [1,5-c] pyrimidine-2(3H)-thione as selective adenosine A(2A) receptor antagonist

Abstract

Adenosine A(2A) receptor (A(2A)R) antagonists have emerged as potential drug candidates to alleviate progression and symptoms of Parkinson's disease (PD), and reduce the dopaminergic side effects. The synthesis of novel compound 8-(furan-2-yl)-3-benzyl thiazolo [5,4-e][1,2,4] triazolo [1,5-c] pyrimidine-2-(3H)-thione (BTTP) was carried out to evaluate the potential of BTTP as A(2A)R antagonist using SCH58261, a standard A(2A)R antagonist. The strong interaction of BTTP with A(2A)R (ΔG=-12.46kcal/mol and K(i)=0.6nM) in silico analysis was confirmed by radioligand receptor binding studies showing high affinity (K(i)=0.004nM) and selectivity with A(2A)R (A(2A)/A(1)=1155-fold). The effect of CGS21680 (selective A(2A)R agonist) induced cAMP concentration (0.1pmol/ml) in HEK293 cells was antagonized with BTTP (0.065pmol/ml) and SCH58261 (0.075pmol/ml). Furthermore, BTTP pre-treated (5, 10 and 20mg/kg) haloperidol-induced mice demonstrated significant attenuation in catalepsy and akinesia. BTTP induced elevation in the striatal dopamine concentration (2.90μM/mg of tissue) was comparable to SCH58261 (2.92μM/mg of tissue) at the dose of 10mg/kg. The results firmly articulate that BTTP possesses potential A(2A)R antagonist activity and can be further explored for the treatment of PD.