biostudies-literatureYin GNational Natural Science Foundation of Chinathe project of the Beijing Municipal Science and Technology Commission2196https://www.ebi.ac.uk/biostudies/studies/S-EPMC9607073biostudies-literatureUnknown14(10)To develop novel radiolabeled amino acid tumor imaging agents, 4-methoxy-<sub>L</sub>-phenylalanine dithiocarbamate (MOPADTC) was synthesized successfully, and two kinds of <sup>99m</sup>Tc-labeled complexes ([<sup>99m</sup>Tc]TcN-MOPADTC and [<sup>99m</sup>Tc]TcO-MOPADTC) with high radiochemical purities (RCP > 95%) were obtained. The in vitro stability and partition coefficient were determined, and the results show that both of these complexes have good in vitro stability; [<sup>99m</sup>Tc]TcO-MOPADTC is hydrophilic, while [<sup>99m</sup>Tc]TcN-MOPADTC is slightly lipophilic. The biodistribution of [<sup>99m</sup>Tc]TcN-MOPADTC and [<sup>99m</sup>Tc]TcO-MOPADTC in mice bearing S180 tumors shows that the tumor uptake and tumor/muscle ratio of [<sup>99m</sup>Tc]TcO-MOPADTC were higher than the tumor uptake and tumor/muscle ratio of [<sup>99m</sup>Tc]TcN-MOPADTC. In addition, the tumor retention of [<sup>99m</sup>Tc]TcO-MOPADTC is better than the tumor retention of [<sup>99m</sup>Tc]TcN-MOPADTC. A competitive inhibition assay was performed, and the results indicate that [<sup>99m</sup>Tc]TcO-MOPADTC may enter cells primarily via the <sub>L</sub>-alanine/<sub>L</sub>-serine/<sub>L</sub>-cysteine (ASC) system. Single-photon emission computed tomography (SPECT) imaging of [<sup>99m</sup>Tc]TcO-MOPADTC shows obvious accumulation in tumor sites, suggesting that [<sup>99m</sup>Tc]TcO-MOPADTC is a novel potential tumor-imaging agent.PharmaceuticsRadiolabeling and Biological Evaluation of Novel <sup>99m</sup>Tc-Nitrido and <sup>99m</sup>Tc-Oxo Complexes with 4-Methoxy-<sub>L</sub>-Phenylalanine Dithiocarbamate for Tumor Imaging.PMC9607073Z1811000022180332207601321771023Jiang YYin GZhang JRuan QfalseRadiolabeling and Biological Evaluation of Novel <sup>99m</sup>Tc-Nitrido and <sup>99m</sup>Tc-Oxo Complexes with 4-Methoxy-<sub>L</sub>-Phenylalanine Dithiocarbamate for Tumor Imaging.To develop novel radiolabeled amino acid tumor imaging agents, 4-methoxy-<sub>L</sub>-phenylalanine dithiocarbamate (MOPADTC) was synthesized successfully, and two kinds of <sup>99m</sup>Tc-labeled complexes ([<sup>99m</sup>Tc]TcN-MOPADTC and [<sup>99m</sup>Tc]TcO-MOPADTC) with high radiochemical purities (RCP > 95%) were obtained. The in vitro stability and partition coefficient were determined, and the results show that both of these complexes have good in vitro stability; [<sup>99m</sup>Tc]TcO-MOPADTC is hydrophilic, while [<sup>99m</sup>Tc]TcN-MOPADTC is slightly lipophilic. The biodistribution of [<sup>99m</sup>Tc]TcN-MOPADTC and [<sup>99m</sup>Tc]TcO-MOPADTC in mice bearing S180 tumors shows that the tumor uptake and tumor/muscle ratio of [<sup>99m</sup>Tc]TcO-MOPADTC were higher than the tumor uptake and tumor/muscle ratio of [<sup>99m</sup>Tc]TcN-MOPADTC. In addition, the tumor retention of [<sup>99m</sup>Tc]TcO-MOPADTC is better than the tumor retention of [<sup>99m</sup>Tc]TcN-MOPADTC. A competitive inhibition assay was performed, and the results indicate that [<sup>99m</sup>Tc]TcO-MOPADTC may enter cells primarily via the <sub>L</sub>-alanine/<sub>L</sub>-serine/<sub>L</sub>-cysteine (ASC) system. Single-photon emission computed tomography (SPECT) imaging of [<sup>99m</sup>Tc]TcO-MOPADTC shows obvious accumulation in tumor sites, suggesting that [<sup>99m</sup>Tc]TcO-MOPADTC is a novel potential tumor-imaging agent.2022-01-01T00:00:00Z2022 Oct2025-04-18T20:20:25.639Z2025-04-07T08:14:41.249ZS-EPMC96070733629763110.3390/pharmaceutics14102196