1,4,7-Triazacyclononane-1,4,7-triacetic acid (NOTA)

1,4,7-Triazacyclononane-1,4,7-triacetic acid (NOTA) is a synthetic chemical chelating agent, widely used in medical imaging and nuclear medicine, particularly for positron emission tomography (PET) radiopharmaceuticals. It consists of a triazacyclononane (nine-membered ring with three nitrogen atoms) core functionalized with three acetic acid side chains, enabling stable and selective complexation of metal ions, such as gallium-68 (^68Ga^), indium-111 (^111In^), and copper-64 (^64Cu^). Its role is to securely bind radiometals to biomolecules for in vivo targeting, but NOTA itself is not a biological target like a receptor, enzyme, or transporter; rather, it is a chemical tool used for radiolabeling purposes in diagnostic agents. Thus, while essential in radiopharmaceutical chemistry and biomedical imaging, it is not a therapeutic target and does not directly participate in biological pathways or disease mechanisms.

Other names

NOTA chelator1,4,7-Triazacyclononane-N,N',N''-triacetic acid2,2′,2″-(1,4,7-triazacyclononane-1,4,7-triyl)triacetic acid