1-Allyl-3,7-dimethyl-8-phenylxanthine

1-Allyl-3,7-dimethyl-8-phenylxanthine is an antagonist of the Adenosine A1-R (A₁ adenosine receptor). 1-Allyl-3,7-dimethyl-8-phenylxanthine is described to block increases in intracellular Ca²⁺ concentration produced by the A₁ receptor agonist 2-chloro-N⁶-cyclopentyl-adenosine but did not antagonize increases produced by the A₂ agonist 2-p-(2-carboxy-ethyl) phenethylamino-5'-N-ethylcarboxyamide adenosine hydrochloride or the A₃ agonist N⁶-2-(4-Aminophenyl)ethyladenosine.