Choi Joon Hun, Choe Yearn Seong, Lee Kyung-Han, Choi Yong, Kim Sang Eun, Kim Byung-Tae
Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Kangnam-ku, Seoul 135-710, Republic of Korea.
Carbohydr Res. 2003 Jan 2;338(1):29-34. doi: 10.1016/s0008-6215(02)00359-2.
A potent inhibitor of beta-galactosidase (EC 3.2.1.23), 2-phenylethyl 1-thio-beta-D-galactopyranoside (PETG), was radioiodinated for noninvasive imaging of LacZ gene expression. In order to introduce radioiodine to the phenyl ring of PETG, 2-(4-bromophenyl)ethanethiol was prepared and attached to the C-1 position of beta-D-galactose pentaacetate under conditions that resulted in the exclusive formation of the beta anomer. The bromo group of PETG was converted to the tributylstannyl group where radioiododemetallation was carried out. Radioiodine-labeled PETG tetraacetate was purified by HPLC, which can be used as a prodrug for biological evaluation or hydrolyzed to 2-(4-[123I/125I]iodophenyl)ethyl 1-thio-beta-D-galactopyranoside ([123I/125I]7) under basic conditions. The resulting radioiodine-labeled PETG was obtained in overall 62% radiochemical yield (decay-corrected) and with specific activity of 46-74 GBq/micromol.
一种β-半乳糖苷酶（EC 3.2.1.23）的强效抑制剂2-苯乙基1-硫代-β-D-吡喃半乳糖苷（PETG）被进行放射性碘化，用于LacZ基因表达的无创成像。为了将放射性碘引入PETG的苯环，制备了2-(4-溴苯基)乙硫醇，并在导致β异头物独家形成的条件下将其连接到β-D-半乳糖五乙酸酯的C-1位。PETG的溴基团被转化为三丁基锡基团，在此进行放射性碘去金属化反应。放射性碘标记的PETG四乙酸酯通过高效液相色谱法纯化，其可用作生物评价的前体药物，或在碱性条件下水解为2-(4-[123I/125I]碘苯基)乙基1-硫代-β-D-吡喃半乳糖苷（[123I/125I]7）。最终获得的放射性碘标记的PETG的总放射化学产率为62%（衰变校正），比活度为46 - 74 GBq/μmol。
