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1 Publication
Rapid module-assisted synthesis of 16alpha-[18F]fluorestradiol-3,17beta-disulfamate
Römer, J.; Füchtner, F.; Steinbach, J.; Kasch, H.;
16alpha-Fluoroestradiol-3,17beta-disulphamate has proven to be a very strong sulphatase inhibitor. Because the sulphatase activity is high in breast cancer tissue there was much hope to image human mammary tumours by using 16alpha-[18F]fluoroestradiol-3,17beta-disulphamate ([18F]FESDS) in PET investigations. For biological characterizing, the new radiotracer had to be made available in high specific activity and in radiochemically pure form. Thus, the module-assisted procedure was developed.

The synthesis of [18F]FESDS consists of two steps. In a first step, 3-methoxymethyloxy-16beta,17beta- sulphuryldioxy-estra-1,3,5(10)-triene (1) reacted with n.c.a. [18F]fluoride. The labelled product was deprotected by acid hydrolysis to give 16alpha-[18F]fluoroestradiol ([18F]FES). In a second step, [18F]FES was sulphamoylated to [18F]FESDS by using sulphamoyl chloride in presence of equivalent amounts of Kryptofix 2.2.2 and potassium carbonate. HPLC purification allowed to obtain pure [18F]FESDS. The synthesis shown in Figure 1 can be carried out in an automated module as a one-pot procedure.

Results: The synthesis required about 90 min from end of bombardment to the final [18F]FESDS ready for use. The time was composed of the time of synthesis (60 min) and the time of column purification (about 30 min). The decay-corrected yield of [18F]FESDS was 22 - 26%. The chemical and radiochemical purity was better than 98%. The specific radioactivity was found to be between 250 and 450 GBq/µmol. When starting with 70 GBq n.c.a. [18F]fluoride, about 8 - 10 GBq [18F]FESDS can be produced. A typical radiochromatogram of the HPLC purification is shown in Fig. 2.
  • Poster
    7th International Symposium on The Synthesis and Applications of Isotopes and Isotopically Labelled Compounds of the International Isotope Society, Dresden, 18.-22.06.2000

Publ.-Id: 3432 - Permalink