@article {doi:10.1002/jlcr.3875,
	title = {Thorium chelators for targeted alpha therapy: Rapid chelation of thorium-226},
	journal = {J. Label. Compd. Radiopharm.},
	volume = {63},
	number = {12},
	year = {2020},
	pages = {502-516},
	abstract = {<p>One of the main challenges in targeted alpha therapy is assuring delivery of the α-particle dose to the targeted cells. Thus, it is critical to identify ligands for α-emitting radiometals that will form complexes that are very stable, both in vitro and in vivo. In this investigation, thorium-227 (t1/2 = 18.70 days) chelation of ligands containing hydroxypyridinonate (HOPO) or picolinic acid (pa) moieties and the stability of the resultant complexes were studied. Chelation reactions were followed by reversed-phased HPLC and gamma spectroscopy. Studies revealed that high 227Th chelation yields could be obtained within 2.5 h or less with ligands containing four Me-3,2-HOPO moieties, 1 (83\%) and 2 (65\%), and also with ligands containing pa moieties, H4octapa 3 (65\%) and H4py4pa 6 (87\%). No reaction occurred with H4neunpa-p-Bn-NO2 4, and the chelation reaction with another pa ligand H4pypa 5 gave inconsistent yields with a very broad radio-HPLC peak. The ligands spermine-(Me-3,2-HOPO)4 1, H4octapa 3, and H4py4pa 6 had high stability (i.e., 87\% of 227Th still bound to the ligand) in phosphate-buffered saline at room temperature over a 6-day period. Preliminary studies with ligand 6 demonstrated efficient chelation of thorium-226 (t1/2 = 30.57 min) when heated to 80\&deg;C for 5 min.</p>},
	keywords = {hydroxypyridinonate (HOPO), metal chelates, octadentate, picolinic acid, TAT, thorium-226, thorium-227, undecadentate},
	doi = {10.1002/jlcr.3875},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/jlcr.3875},
	author = {Ferrier, Maryline G. and Li, Yawen and Chyan, Ming-Kuan and Wong, Roger and LI, LILY and Spreckelmeyer, Sarah and Hamlin, Donald K. and Mastren, Tara and Fassbender, Michael E. and Orvig, Chris and Wilbur, D. Scott}
}
