Synthesis and in vivo evaluation of [18F]2-(4-(4-(2-(2-fluoroethoxy)phenyl)piperazin-1-yl)butyl)-4-methyl-1,2,4-triazine-3,5(2H,4H)-dione ([18F]FECUMI-101) as an imaging probe for 5-HT1A receptor agonist in nonhuman primates
作者:Vattoly J. Majo、Matthew S. Milak、Jaya Prabhakaran、Pratap Mali、Lyudmila Savenkova、Norman R. Simpson、J. John Mann、Ramin V. Parsey、J. S. Dileep Kumar
DOI:10.1016/j.bmc.2013.05.050
日期:2013.9
The 5-HT1AR partial agonist PET radiotracer, [C-11]CUMI-101, has advantages over an antagonist radiotracer as it binds preferentially to the high affinity state of the receptor and thereby provides more functionally meaningful information. The major drawback of C-11 tracers is the lack of cyclotron facility in many health care centers thereby limiting widespread clinical or research use. We identified the fluoroethyl derivative, 2-(4-(4-(2-(2-fluoroethoxy)phenyl)piperazin-l-yl)buty1)-4-methyl-1,2,4-triazine3,5(2H,4H)dione (FECUMI-101) (K-i = 0.1 nM; E-max = 77%; EC50 = 0.65 nM) as a partial agonist 5-HT1AR ligand of the parent ligand CUM1-101. FECUMI-101 is radiolabeled with F-18 by O-fluoroethylation of the corresponding desmethyl analogue (1) with [F-18]fluoroethyltosylate in DMSO in the presence of 1.6 equiv of K2CO3 in 45 +/- 5% yield (EOS). PET shows [F-18]FECUMI-101 binds specifically to 5-HT1AR enriched brain regions of baboon. The specificity of [F-18]FECUMI-101 binding to 5-HT1AR was confirmed by challenge studies with the known 5-HT1AR ligand WAY100635. These findings indicate that [F-18]FECUM1-101 can be a viable agonist ligand for the in vivo quantification of high affinity 5-HT1AR with PET. (C) 2013 Elsevier Ltd. All rights reserved.