Radiosynthesis and evaluation of 18F-labeled aliphatic phosphonium cations as a myocardial imaging agent for positron emission tomography

Abstract

(18)F-labeled aliphatic phosphonium cations [(18)F]3 and [(18)F]6 might have potential as novel myocardial agents for PET and could prove useful in clinical cardiac PET/computed tomography applications.

Emerging Tracers for Nuclear Cardiac PET Imaging

“…1. 18 F-labeled TPP derivatives are classified into three types (type 1, short aliphatic or ether form linkers are adopted between the triphenylphosphonium and 18 F; type 2, 18 F-substituted phenyl or benzyl group is attached to triphenylphosphine; and type 3, 18 Flabeled linkers are conjugated to triphenylphosphine derivatives by click chemistry) [30,[35][36][37][38][39][40][41][42][43][44][45][46][47][48][49]. Among these cations, 4-18 F-fluorobenzyltriphenylphosphonium ( 18 F-FBnTP) showed promise for the first time as a myocardial perfusion PET agent.…”

“…However, in vivo characteristics of 18 F-FBnTP, such as higher uptake and longer retention in the heart and more rapid wash out from the liver, need to be improved. 18 [38,[41][42][43][44]. Lipophilicity of the radiotracer could control myocardial selectivity and hepatic clearance.…”

Radiolabeled Phosphonium Salts as Mitochondrial Voltage Sensors for Positron Emission Tomography Myocardial Imaging Agents

“…Therefore, radiolabeled TPP derivatives are promising candidates for myocardial imaging [19,20]. Table 1 shows the radiolabeled TPP derivatives that have been developed [15,16,[21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36]. The chemical structures of radiolabeled TPP derivatives are shown in Fig.…”

“…Thus we developed novel 18 F-labeled tetraphenylphosphonium cation derivatives, fluoroalkyltriphenylphosphonium cations (FATPs). Alkyl chain conjugated triphenylphosphonium cation, have improved characteristics through lipophilicity control [28][29][30][31][32].…”

“…range of lipophilicity suitable for PET myocardial imaging agents. 18 F-FATPs were prepared as described previously [28][29][30][31][32]. It took a total reaction time of less than 60 minutes for 18 F-FATPs to be ready for tracer injection.…”