The preparation of the a carboxyl 9-fluorenylmethyl(FM) ester of Boc-aspartic acid is described.This new protected amino acid linked to the polymeric support by βcarboxyl group offers a convenient strategy for the sy...The preparation of the a carboxyl 9-fluorenylmethyl(FM) ester of Boc-aspartic acid is described.This new protected amino acid linked to the polymeric support by βcarboxyl group offers a convenient strategy for the synthesis of head-to-tail cyclopeptides while the peptides remained attached to the polymeric support.展开更多
The cyclic peptide YG5 and the t-butyloxycarbonyl(Boc)-modified analog(Boc-YG5) were labeled with radioiodine.The radiochemical purity of 131I-YG5 or 131I-Boc-YG5 was almost 100% after purification by RP-HPLC.Biodistr...The cyclic peptide YG5 and the t-butyloxycarbonyl(Boc)-modified analog(Boc-YG5) were labeled with radioiodine.The radiochemical purity of 131I-YG5 or 131I-Boc-YG5 was almost 100% after purification by RP-HPLC.Biodistribution in BALB/C nude mice bearing MCF-7 tumor was measured.After t-butyloxycarbonyl(Boc)-modification,the 131I-Boc-YG5 was quite resistant to deiodination in vivo,resulting in negligible radioactivity accumulation in thyroid.The radiotracer clearance in tumor became faster,the absolute tumor uptake decreased for 131I-Boc-YG5,but the tumor-to-tissue uptake ratios increased.The uptake ratios of tumor to muscle,blood,heart,and lung at 1 h post injection reached 4.73,1.70,4.09 and 1.70,respectively.It is demonstrated that Boc-group is an effective prosthetic one to prevent deiodination in vivo and improve tumor imaging for radioiodinated NGR.展开更多
文摘The preparation of the a carboxyl 9-fluorenylmethyl(FM) ester of Boc-aspartic acid is described.This new protected amino acid linked to the polymeric support by βcarboxyl group offers a convenient strategy for the synthesis of head-to-tail cyclopeptides while the peptides remained attached to the polymeric support.
基金Support by National Natural Science Foundation of China (No. 20771011 and 21071010)the Ministry of Science and Technology of China (No. 2006CB705700)
文摘The cyclic peptide YG5 and the t-butyloxycarbonyl(Boc)-modified analog(Boc-YG5) were labeled with radioiodine.The radiochemical purity of 131I-YG5 or 131I-Boc-YG5 was almost 100% after purification by RP-HPLC.Biodistribution in BALB/C nude mice bearing MCF-7 tumor was measured.After t-butyloxycarbonyl(Boc)-modification,the 131I-Boc-YG5 was quite resistant to deiodination in vivo,resulting in negligible radioactivity accumulation in thyroid.The radiotracer clearance in tumor became faster,the absolute tumor uptake decreased for 131I-Boc-YG5,but the tumor-to-tissue uptake ratios increased.The uptake ratios of tumor to muscle,blood,heart,and lung at 1 h post injection reached 4.73,1.70,4.09 and 1.70,respectively.It is demonstrated that Boc-group is an effective prosthetic one to prevent deiodination in vivo and improve tumor imaging for radioiodinated NGR.
基金Project supported by the National Natural Science Foundation of China(No.21502076)the Natural Science Foundation of Jiangxi Province(No.20161BAB213068)+1 种基金the Hundred-Talent Program(Hefei)the Outstanding Young Talent Program of Jiangxi Province(No.20171BCB23039)~~
