Synthesis and Biological Evaluation of 2-amino-3-phenylpropanoic Acid Derivatives Labeled With ¹⁸F

Methyl-2-(4-(2-fluoroethoxy) benzamido)-3-phenylpropanoate (MFBPA) and its hydrolysis product 2-(4-(2-fluoroethoxy)benzamido)-3-phenylpropanoic acid (FBPA) were synthesized and labeled by ¹⁸F. To evaluate applicability of ¹⁸F-MFBPA and ¹⁸F-FBPA in detecting malignant fibrosarcoma, some studies were carried on biodistribution, stabilities in vitro or in vivo and autoradiophotography. After 60 min of intravenous injection the accumulations of ¹⁸F-MFBPA and ¹⁸F-FBPA in tumor, muscle, blood and brain were 0.78±0.02, 0.72±0.04, 0.66±0.07, 0.38±0.03%ID/g and 0.95±0.05, 0.64±0.06, 0.65±0.04, 0.34±0.01%ID/g, respectively. Their ratios of tumor to muscle， tumor to blood, and tumor to brain were 1.18, 1.08, 2.05 and 1.46 1.48，2.79, respectively. The results indicated that ¹⁸F-FBPA might have more potential to be PET imaging agent.