Structure−Activity Relationship Study of Prion Inhibition by 2-Aminopyridine-3,5-dicarbonitrile-Based Compounds:  Parallel Synthesis, Bioactivity, and in Vitro Pharmacokinetics

2-Aminopyridine-3,5-dicarbonitrile compounds were previously identified as mimetics of dominant-negative prion protein mutants and inhibit prion replication in cultured cells. Here, we report findings from a comprehensive structure-activity relationship study of the 6-aminopyridine-3,5-dicarbonitrile scaffold. We identify compounds with significantly improved bioactivity (approximately 40-fold) against replication of the infectious prion isoform (PrPSc) and suitable pharmacokinetic profiles to warrant evaluation in animal models of prion disease.