The synthesis of 7α-methyl-substituted estrogens labeled with fluorine-18: potential breast tumor imaging agents
作者:H VANBROCKLIN、A LIU、M WELCH、J ONEIL、J KATZENELLENBOGEN
DOI:10.1016/0039-128x(94)90043-4
日期:1994.1
minutes for the E2 series, and 120 minutes for the EE2 series, and the effective specific activities were 158-1213 Ci/mmol. In nearly every case, the 7 alpha-methyl substituent increases ER binding affinity (measured at 25 C) and decreases binding to high affinity serum steroid binding proteins, alphafetoprotein, and sex steroid binding protein; this substituent, however, increases the lipophilicity and
据报道7个α-甲基取代基增加了雌二醇对雌激素受体(ER)的结合亲和力。为了评估该取代基是否会改善18F标记雌激素的体外结合特性和体内组织分布,我们正在开发这些18F标记雌激素作为用于ER阳性乳腺肿瘤的正电子发射断层扫描(PET)成像剂, 7α-甲基雌二醇的类似物。通过用18F氟离子亲核取代相应的差向异构体雌酮三氟甲磺酸盐,将这些配体标记为18F在16 alpha或16 beta位置。氢化铝锂还原提供了雌二醇(E2)系列,而三甲基甲硅烷基乙炔化锂的添加提供了17α-乙炔基雌二醇(EE2)系列。E2系列的合成时间为85分钟,EE2系列的合成时间为120分钟,衰减校正后的产率为2-35%,有效比活度为158-1213 Ci / mmol。在几乎每种情况下,7个α-甲基取代基都会增加ER结合亲和力(在25 C下测量),并降低与高亲和力血清类固醇结合蛋白,甲胎蛋白和性类固醇结合蛋白的结合;但是,该取