PD 144418 or 1,2,3,6-tetrahydro-5-[3-(4-methylphenyl)-5-isoxazolyl]-1-propylpyridine is a potent and selective ligand for the sigma-1 receptor, with a reported binding affinity of Ki = 0.08 ± 0.01 nM, and 17,212 times selectivity over the sigma-2 receptor.[1]
References
^Akunne HC, Whetzel SZ, Wiley JN, Corbin AE, Ninteman FW, Tecle H, Pei Y, Pugsley TA, Heffner TG (January 1997). "The pharmacology of the novel and selective sigma ligand, PD 144418". Neuropharmacology. 36 (1): 51–62. doi:10.1016/S0028-3908(96)00161-X. PMID9144641. S2CID1356055.