Two novel triflate precursors for radiolabelling of L-tyrosine in positron emission tomography (PET) for tumor imaging,O-(2-trifluoromethanesulfonyloxyethyl)-N-(tert-butoxycarbonyl)-L-tyrosine methyl ester 9a and O-(2...Two novel triflate precursors for radiolabelling of L-tyrosine in positron emission tomography (PET) for tumor imaging,O-(2-trifluoromethanesulfonyloxyethyl)-N-(tert-butoxycarbonyl)-L-tyrosine methyl ester 9a and O-(2-trifluoromethanesulfonyloxyethyl)-N-(tert-butoxycarbonyl)-L-tyrosine tert-butyl ester 9b,are synthesized. The triflate agent,9a or 9b,is prepared by esterification of methanol or transesterification of tert-butyl acetate with L-tyrosine,protection of the amine group with di-tert-butyl dicarbonate,alkylation with chlorohydrin,and triflation with trifluoromethanesulfonic anhydride in four steps with overall yields of 30% and 15%,respectively.展开更多
O-(2-[18F]fluoroethyl) -L-tyrosine([18F]FET) ,a fluorine-18 labeled analogue of tyrosine,has been syn-thesized and biologically evaluated in tumor-bearing mice. The whole synthesis procedure is com-pleted within 50 mi...O-(2-[18F]fluoroethyl) -L-tyrosine([18F]FET) ,a fluorine-18 labeled analogue of tyrosine,has been syn-thesized and biologically evaluated in tumor-bearing mice. The whole synthesis procedure is com-pleted within 50 min. The radiochemical yield is about 40%(no decay corrected) and radiochemical purity more than 97% after simplified solid phase extraction. [18F]FET shows rapid,high uptake and long retention in the tumor as well as low uptake in the brain. The ratios of tumor-to-muscle(T/M) and tumor-to-blood(T/B) of [18F]FET are similar to those of [18F]FDG,but the ratios of tumor-to-brain(T/Br) are 2-3 times higher than that of [18F]FDG. Autoradiography of [18F]FET demonstrates a remarkable accumulation in melanoma with high contrast. It appears to be a probable competitive candidate for melanoma imaging with PET.展开更多
文摘Two novel triflate precursors for radiolabelling of L-tyrosine in positron emission tomography (PET) for tumor imaging,O-(2-trifluoromethanesulfonyloxyethyl)-N-(tert-butoxycarbonyl)-L-tyrosine methyl ester 9a and O-(2-trifluoromethanesulfonyloxyethyl)-N-(tert-butoxycarbonyl)-L-tyrosine tert-butyl ester 9b,are synthesized. The triflate agent,9a or 9b,is prepared by esterification of methanol or transesterification of tert-butyl acetate with L-tyrosine,protection of the amine group with di-tert-butyl dicarbonate,alkylation with chlorohydrin,and triflation with trifluoromethanesulfonic anhydride in four steps with overall yields of 30% and 15%,respectively.
基金Supported by the Knowledge Innovation Project of Chinese Academy of Sciences (No. KJCX1-SW-08) the National Natural Science Foundation of China (Grant No. 30371634)
文摘O-(2-[18F]fluoroethyl) -L-tyrosine([18F]FET) ,a fluorine-18 labeled analogue of tyrosine,has been syn-thesized and biologically evaluated in tumor-bearing mice. The whole synthesis procedure is com-pleted within 50 min. The radiochemical yield is about 40%(no decay corrected) and radiochemical purity more than 97% after simplified solid phase extraction. [18F]FET shows rapid,high uptake and long retention in the tumor as well as low uptake in the brain. The ratios of tumor-to-muscle(T/M) and tumor-to-blood(T/B) of [18F]FET are similar to those of [18F]FDG,but the ratios of tumor-to-brain(T/Br) are 2-3 times higher than that of [18F]FDG. Autoradiography of [18F]FET demonstrates a remarkable accumulation in melanoma with high contrast. It appears to be a probable competitive candidate for melanoma imaging with PET.
