Synthesis of 131I labeled diiodothyronine (131I-T2)

Objective: To synthesise 131I-T2 as the basis for future synthesis of 131I-T2S with sulfation. Methods: Firstly 3-T1 was radiolabeled with 131I with chloramine-T(Ch-T) labeling method. Then gel column chromatography and paper chromatography were used for separation and purification. Measurement of the labeling efficiency, radiochemical purity,stability of labeled compound, and identification of the product of immune activity were carried out. Results: The radiolabeling yield of the labeled compound produced with the modified Ch-T method was about 65.1%±4.5% (n=5) and the radiochemical purity was about 96.5%±1.1% (n=5). After 10d storage at -20 degree C, the radiochemical purity of the product still remained above 90%. Conclusion: High rate of labeling efficiency and good stability could be obtained with Ch-T labeling method. (authors)