GPR17 is believed to be a novel target for the development of new therapeutic approaches to human stroke and multiple sclerosis. Hence, the selection of GPR17 ligands may be a potent way to reduce the progression of ischemic damage. New potential ligands for GPR17, mono-, di-, and triphosphate adenosine nucleotides substituted at N6-position with a methyl and a cyclopentyl group were synthesized. The ability of new ligands to bind GPR17 was evaluated using frontal affinity chromatography-mass spectrometry (FAC-MS) method. Cangrelor, MRS2179, and uridine diphosphate were selected as the reference compounds. The new triphosphate derivatives 9 and 10 were considered as the new GPR17 ligands. The compound 10 was eluted with breakthrough time (bt) between cangrelor and MRS 2179 (compound 10, bt=12.25; cangrelor, bt=24.55, and MRS 2179, bt=7.10), while the breakthrough volume of compound 9 was similar to that of MRS 2179 (compound 9, bt=7.53 and MRS 2179, bt=7.10). N6-cyclopentyATP 10 is medium-high affinity ligand of GPR17, while the corresponding N6-methyl derivative 9 is a medium affinity ligand similar to MRS 2179. Hence, the new N6-cyclopentylATP 10 might be a good candidate for the pharmacological characterization of GPR17.

Keywords: Affinity Labels, Chromatography, Affinity, Gas Chromatography-Mass Spectrometry