biostudies-literatureOlson APOffice of Isotope Research and Development and ProductionWorkforce Development for Teachers and ScientistsNational Cancer InstituteNCI NIH HHSNational Institutes of HealthOffice of Isotope R and D and ProductionNIH HHSe202423878https://www.ebi.ac.uk/biostudies/studies/S-EPMC12536330biostudies-literatureUnknown64(15)Antimony-119 (¹¹⁹Sb) is one of the most attractive Auger-electron emitters identified to date, but it remains practically unexplored for targeted radiotherapy because no chelators have been identified to stably bind this metalloid in vivo. In a departure from current studies focused on chelator development for Sb(III), we explore the chelation chemistry of Sb(V) using the tris-catecholate ligand TREN-CAM. Through a combination of radiolabeling, spectroscopic, solid-state, and computational studies, the radiochemistry and structural chemistry of TREN-CAM with ^1XX/natSb(V) were established. The resulting [^1XXSb]Sb-TREN-CAM complex remained intact for several days in human serum, signifying high stability under biological conditions. Finally, the first in vivoAngewandte Chemie (International ed. in English)Towards the Stable Chelation of Radioantimony(V) for Targeted Auger Theranostics.PMC12536330F31 CA239617F31CA239617P01CA250972P01 CA250972Ivanov ASDierolf MADriscoll DMKertesz VVerich FSchrage BRBecker KVFletcher LSBoros EOlson APEngle JWWhite FDGirish NThiele NAIslam MFAluicio-Sarduy ESimms MEfalseTowards the Stable Chelation of Radioantimony(V) for Targeted Auger Theranostics.Antimony-119 (¹¹⁹Sb) is one of the most attractive Auger-electron emitters identified to date, but it remains practically unexplored for targeted radiotherapy because no chelators have been identified to stably bind this metalloid in vivo. In a departure from current studies focused on chelator development for Sb(III), we explore the chelation chemistry of Sb(V) using the tris-catecholate ligand TREN-CAM. Through a combination of radiolabeling, spectroscopic, solid-state, and computational studies, the radiochemistry and structural chemistry of TREN-CAM with ^1XX/natSb(V) were established. The resulting [^1XXSb]Sb-TREN-CAM complex remained intact for several days in human serum, signifying high stability under biological conditions. Finally, the first in vivo2025-01-01T00:00:00Z2025 Apr2026-06-04T14:14:44.863Z2026-05-10T03:11:33.569ZS-EPMC125363303987845710.1002/anie.202423878