It has 520-fold selectivity for the adenosine A2A receptor over the adenosine A1 receptor (Ki = 54nM and 28,000nM for the rat receptors, respectively).[1][2] Its affinities for the adenosine A2B and A3 receptors are similarly low (Ki = 8,200nM and >10,000nM, respectively).[3]
The drug was one of the first selective adenosine A2A receptor antagonists to be developed.[1] However, in addition to its adenosine receptor antagonism, CSC was subsequently found to be a potent monoamine oxidase B (MAO-B) inhibitor (Ki = 80.6nM for baboon MAO-B).[2][1][3][7][8] CSC was first described in the scientific literature by 1993.[9]
^Hauber W, Neuscheler P, Nagel J, Müller CE (October 2001). "Catalepsy induced by a blockade of dopamine D1 or D2 receptors was reversed by a concomitant blockade of adenosine A(2A) receptors in the caudate-putamen of rats". Eur J Neurosci. 14 (8): 1287–1293. doi:10.1046/j.0953-816x.2001.01759.x. PMID11703457.
^Pretorius J, Malan SF, Castagnoli N, Bergh JJ, Petzer JP (September 2008). "Dual inhibition of monoamine oxidase B and antagonism of the adenosine A(2A) receptor by (E,E)-8-(4-phenylbutadien-1-yl)caffeine analogues". Bioorg Med Chem. 16 (18): 8676–8684. doi:10.1016/j.bmc.2008.07.088. PMID18723354.