11C-para-aminobenzoic acid

11C-para-aminobenzoic acid ([11C]PABA) is a radiopharmaceutical small molecule developed as a metabolic imaging agent for the non-invasive detection of bacterial infections using Positron Emission Tomography (PET). It is a radiolabeled analog of para-aminobenzoic acid (PABA), a critical substrate in the bacterial folate synthesis pathway. While humans and other mammals lack the enzymes to synthesize folate and must obtain it through their diet, most bacteria must produce it de novo. [11C]PABA is selectively taken up by bacteria and incorporated into the folate pathway via the enzyme dihydropteroate synthase (DHPS). This distinct metabolic requirement allows [11C]PABA to differentiate bacterial infections from sterile inflammation or neoplastic growth, providing a specific diagnostic tool for identifying deep-seated infections and monitoring therapeutic response.

Other names

carbon-11-para-aminobenzoic acidcarbon11-para-aminobenzoic acidcarbon 11-para-aminobenzoic acid[11C]para-aminobenzoic acid4-aminobenzoic acid, 11C-labeled