7.alpha.-Methyl- and 11.beta.-ethoxy-substitution of iodine-125-labeled [125I]16.alpha.-iodoestradiol: effect on estrogen receptor-mediated target tissue uptake
摘要:
The 7alpha-methyl and 11beta-ethoxy derivatives of 16alpha-[I-125]iodoestradiol were prepared via halogen exchange with I-125 of the corresponding 16beta-bromoestradiol precursors. The 16alpha-bromo derivatives were obtained via halogenation of the analogous 17-enol acetate, epimerization to the 16beta-isomer, and hydride reduction. Stereochemical assignments were based on high resolution H-1 NMR. To evaluate the effect of the nature and stereochemistry of the 16-halo substituent on the relative binding affinity for the estrogen receptor, the analogous 16-chloro derivatives were also prepared. The highest binding affinities were observed with the 7alpha-methyl-16alpha-haloestradiols, particularly the bromo and chloro derivatives while the 16alpha-iodo derivatives gave somewhat lower values. Both the 11beta-ethoxy and 7alpha-methyl-16alpha-[I-125]iodoestradiols localize in the uteri of immature female rats via a receptor-mediated process. Rapid blood clearance of the I-125-labeled 7alpha-methyl derivative results in lower I-125 uptake by the uterus as well as nontarget organs as compared to the 11beta-substituted estradiol analogs. However, uterus to blood and nontarget ratios are more favorable for the 7alpha-methyl-16alpha-[I-125]iodoestradiol as compared to the analogous 11beta-ethoxy derivatives suggesting that this compound substituted with I-125 may be useful for the in vivo imaging of estrogen receptor-rich breast tumors by single photon emission computerized tomography.
7.alpha.-Methyl- and 11.beta.-ethoxy-substitution of iodine-125-labeled [125I]16.alpha.-iodoestradiol: effect on estrogen receptor-mediated target tissue uptake
摘要:
The 7alpha-methyl and 11beta-ethoxy derivatives of 16alpha-[I-125]iodoestradiol were prepared via halogen exchange with I-125 of the corresponding 16beta-bromoestradiol precursors. The 16alpha-bromo derivatives were obtained via halogenation of the analogous 17-enol acetate, epimerization to the 16beta-isomer, and hydride reduction. Stereochemical assignments were based on high resolution H-1 NMR. To evaluate the effect of the nature and stereochemistry of the 16-halo substituent on the relative binding affinity for the estrogen receptor, the analogous 16-chloro derivatives were also prepared. The highest binding affinities were observed with the 7alpha-methyl-16alpha-haloestradiols, particularly the bromo and chloro derivatives while the 16alpha-iodo derivatives gave somewhat lower values. Both the 11beta-ethoxy and 7alpha-methyl-16alpha-[I-125]iodoestradiols localize in the uteri of immature female rats via a receptor-mediated process. Rapid blood clearance of the I-125-labeled 7alpha-methyl derivative results in lower I-125 uptake by the uterus as well as nontarget organs as compared to the 11beta-substituted estradiol analogs. However, uterus to blood and nontarget ratios are more favorable for the 7alpha-methyl-16alpha-[I-125]iodoestradiol as compared to the analogous 11beta-ethoxy derivatives suggesting that this compound substituted with I-125 may be useful for the in vivo imaging of estrogen receptor-rich breast tumors by single photon emission computerized tomography.
7.alpha.-Methyl- and 11.beta.-ethoxy-substitution of iodine-125-labeled [125I]16.alpha.-iodoestradiol: effect on estrogen receptor-mediated target tissue uptake
作者:Hasrat Ali、Jacques Rousseau、Johan E. Van Lier
DOI:10.1021/jm00054a011
日期:1993.1
The 7alpha-methyl and 11beta-ethoxy derivatives of 16alpha-[I-125]iodoestradiol were prepared via halogen exchange with I-125 of the corresponding 16beta-bromoestradiol precursors. The 16alpha-bromo derivatives were obtained via halogenation of the analogous 17-enol acetate, epimerization to the 16beta-isomer, and hydride reduction. Stereochemical assignments were based on high resolution H-1 NMR. To evaluate the effect of the nature and stereochemistry of the 16-halo substituent on the relative binding affinity for the estrogen receptor, the analogous 16-chloro derivatives were also prepared. The highest binding affinities were observed with the 7alpha-methyl-16alpha-haloestradiols, particularly the bromo and chloro derivatives while the 16alpha-iodo derivatives gave somewhat lower values. Both the 11beta-ethoxy and 7alpha-methyl-16alpha-[I-125]iodoestradiols localize in the uteri of immature female rats via a receptor-mediated process. Rapid blood clearance of the I-125-labeled 7alpha-methyl derivative results in lower I-125 uptake by the uterus as well as nontarget organs as compared to the 11beta-substituted estradiol analogs. However, uterus to blood and nontarget ratios are more favorable for the 7alpha-methyl-16alpha-[I-125]iodoestradiol as compared to the analogous 11beta-ethoxy derivatives suggesting that this compound substituted with I-125 may be useful for the in vivo imaging of estrogen receptor-rich breast tumors by single photon emission computerized tomography.