Synthesis and preliminary pharmacological evaluation of 5-(3-18F fluoropropyloxy)-L-tryptophan / 中国药学杂志

ABSTRACT

OBJECTIVE: To develop 5-(3-fluoropropyloxy)-L-tryptophan(5-18FPTP)as a new amino acid positron emission tomography (PET) tracer for the differentiation of tumor and inflammation. METHODS: 5-18FPTP was prepared by nucleophilic fluorination and alkylation reaction via a two-step procedure. Twenty mice were divided into five groups randomly and the biodistribution of 5-18FPTP in normal mice was determined at different time after injecting the tracer by tail vein. Also, two mice bearing tumor and inflammation received PET imaging at 60 min after injecting the tracer to detect the uptake of the tracer in tumor and inflammatory tissue. RESULTS: The overall synthesis time of 5-18FPTP was about 60 min, the overall radiochemical yield with no decay correction was (21±4.6)%, and the radiochemical purity was more than 95%. High uptake and long retention time of 5-18FPTP in liver, kidney and blood were observed. But low uptake in brain and muscle were found. Furthermore, high uptake of 5-18FPTP in tumor but almost no uptake of 5-18FPTP in inflammatory tissue were observed. CONCLUSION: 5-18FPTP is easy to prepare and can be used to differentiate tumors and inflammatory tissues. It seems to be a potential amino acid tracer for tumor imaging with PET.