Improvement Of Typical Fluorine-18 Labeled PET Radiotracers Synthesis Process And Its Application

PET molecular imaging technology is considered the most important part of nuclear medicine.PET can noninvasively,dynamically and quantitatively study the chemical and physiological changes of specific markers in animals,and also can observe and evaluate the life activities of DNA synthesis,gene expression,cell metabolism,cell proliferation and apoptosis.PET imaging can be visualized by detecting the y-rays which are generated during the positron annihilation effect of the radiotracers.Therefore,the development of PET technology is inseparable from the synthesis and development of PET radiotracers.Among numerous isotopes,18F appears to be the best candidate for PET radiotracers by virtue of its favorable physical and nuclear characteristics.With the increasing application of 18F labeled radiotracers in PET,higher requirements should for the synthesis and development of 18F labeled radiotracers been put forward.Firstly,the synthesis process of 18F-FHBG has been optimized because of its wide range of applications but low radiochemical yield.After improving the process,18F-FHBG radiochemical yield increased to 20 ± 2.5%(n.d,c),which has surpassed the reported yield in the literature for the synthesis of 18F-FHBG using Tosyl-FHBG as a precursor.Nevertheless,radiohemical purity reached 99%.In addition,cellular and animal level experiments have been carried out to verify the 18F-FHBG specificimaging,which is good for further imaging applications of 18F-FHBG.Subsequently,Tau protein specific radiotracer 18F-T807 was successfully synthesized and its synthesis process was optimized.The radiochemical yield of 18F-T807 could reach 19 ± 1.8%(n.d.c),and radiohemical purity reached 99%.At the same time,the AD rat model which incorporates okadaic acid in inducing Tau hyperphosphorylation has many advantages,therefore,we firstly applied 18F-T807 to AD model.Finally,a novel labeling method of iodine ylide 18F-labeled aromatic radiotracer was developed to synthesize 18F-safinamide,which has potential application in the study of Parkinson's disease(PD).A new method for the synthesis of PET radiotracers was explored.Therefore,this study could lay the foundation for the synthesis of new aromatic PET radiotracers.