DOTMA丨CAS 104872-42-6

DOTMA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetra(methyl phosphonic acid)) is a macrocyclic chelating agent primarily used in the preparation of metal complexes for medical imaging and radiopharmaceutical applications. It forms highly stable complexes with lanthanide and transition metal ions, such as gadolinium (Gd³⁺), which are widely employed in magnetic resonance imaging (MRI) contrast agents. DOTMA is also utilized in the synthesis of radiometal-labeled compounds for positron emission tomography (PET) and single-photon emission computed tomography (SPECT), where strong metal binding prevents metal ion dissociation, enhancing imaging safety and precision. Additionally, DOTMA-based chelates are used in research and drug delivery systems that require controlled coordination of metal ions, as well as in the development of functional materials, including luminescent and paramagnetic compounds for diagnostic or analytical applications.

The main benefits of DOTMA lie in its exceptional metal-binding stability and kinetic inertness, which reduce the risk of metal ion release in biological environments. Its tetra-phosphonate functionality provides strong, multidentate coordination, making DOTMA chelates thermodynamically and kinetically more stable than many other macrocyclic ligands. This stability enhances safety in vivo, particularly for gadolinium-based MRI contrast agents, by minimizing potential toxicity. DOTMA also allows fine-tuning of the chelate's physicochemical properties, such as solubility, charge, and relaxivity, which improves imaging performance and tissue targeting. Furthermore, the robust coordination chemistry enables consistent, reproducible preparation of radiometal complexes for PET or SPECT imaging, supporting high-quality diagnostic outcomes and efficient synthesis workflows.