This compound, CAS No. 58966-93-1, is used to develop NOTA chelator used for Radionuclide Drug Conjugates, RDC. NOTA is one of the oldest and most successful macrocyclic chelator for Ga-67/68 and Cu-64, and is generally considered to be the gold standard for Ga³⁺ chelation. NOTA possesses favorable radiolabeling conditions (30~60 minutes under room temperature) and excellent in vivo stability.

Structure of CAS No. 58966-93-1

Structure of NOTA

NOTA, a well-recognized macrocyclic polyaminocarboxylate BFCA, is especially tailored for small radionuclides like gallium and copper due to its small bonding cavity. Being the gold standard for Ga-68 radiolabeling, NOTA ensures excellent in vivo stability and facilitates a rapid and straightforward complexation process at room temperature and a moderate pH for 30-60 minutes. The Ga-68-NOTA complex, exhibiting an octahedral coordination geometry and high thermodynamic stability, shows impressive in vivo stability in plasma. Studies have found that the radiochemical yield of the Ga-68-NOTA complex exceeds 95% at room temperature and pH 3 within 10 minutes, and remains stable in human plasma for 4.5 hours at body temperature (37 °C). 

Apart from Ga-68, NOTA forms more stable complexes with Cu-64 compared to other BFCAs such as DOTA, TETA, DTPA, and EDTA. The Cu-64–NOTA complex displays minimal Cu-64 loss depending on Cu²⁺ concentration and pH, unlike the Cu-64–NOTA complex where the loss rate of Cu-64 speeds up with increasing Cu²⁺ concentration and pH. With a high thermodynamic stability constant (LogK_ML = 21.6), the Cu-64–NOTA complex can be radiolabeled at room temperature and pH 5.5-6.5 for 30-60 minutes. 

References

NOTA can be synthesized using this compound CAS No. 58966-93-1 with following reference root of synthesis.

References