Facile radiosynthesis of 18F-labeled β-glutamic acid as a new PET tracer for imaging lung cancer

In this paper, N-(2-[18F]fluoropropionyl)-β-glutamic acid 8 ([18F]FP-β-Glu), a new N-substituted 18F-labeled amino acid tracer, was synthesized from the precursor 4 (diethyl 3-(2-bromopropanamido)pentanedioate) via a two-step reaction on the modified FDG synthesizer. The radiochemical yield was 20 ± 5% (n = 10, decay-corrected) from [18F]fluoride within 40 min, the radiochemical purity was 98%. Moreover, microPET studies showed that [18F]FP-β-Glu 8 exhibited rapid tumor uptake and good tumor-to-lung ratio in SPC-A-1 tumor-bearing mice. A high accumulation of radioactivity was found in the kidneys and bladder, which suggested that the tracer was mainly eliminated through the urinary system.