11C-trimethoprim

**11C-trimethoprim** is a radiolabeled form of the antibiotic trimethoprim in which the molecule is tagged with the radioactive isotope carbon-11. It is used as a positron emission tomography (PET) imaging agent to detect bacterial infections in vivo. The mechanism of action relies on its selective binding to bacterial dihydrofolate reductase (DHFR), an enzyme essential for folate metabolism and DNA synthesis in bacteria. This allows for specific imaging of sites containing bacteria or genetically engineered cells expressing bacterial DHFR. Unlike therapeutic trimethoprim, 11C-trimethoprim is not used to treat infections but rather to visualize them using PET scans[6][8][10]. First-in-human studies have demonstrated its ability to accumulate at infection sites regardless of whether bacteria are sensitive or resistant to standard trimethoprim therapy[8][10].

Other names

carbon-11 trimethoprimcarbon11 trimethoprimcarbon 11 trimethoprimradiolabeled trimethoprim