Synthesis, receptor binding, and tissue distribution of (17.alpha.,20E)- and (17.alpha.,20Z)-21-[125I]Iodo-19-norpregna-1,3,5-(10),20-tetraene-3,17-diol
摘要:
The isomeric (17 alpha,20E)- and (17 alpha,20Z)-(iodovinyl)estradiol derivatives 3 and 6, and their no-carrier-added (nca) [125I]iodovinyl analogues, were tested for their relative target tissue retention and binding affinity for the estrogen receptor. The (iodovinyl)estradiols 3 and 6 were prepared via destannylation of the (17 alpha,20E)- and (17 alpha,20Z)-tributylstannyl precursors 2 and 4 with retention of configuration. Selective formation of the E or Z isomers 2 and 4 during the reaction of 17 alpha-ethynylestradiol 1a with tri-n-butyltin hydride was controlled by the presence or absence of the catalyst, the polarity of the solvent, and the reaction temperature. The nca [125I]iodovinyl analogues [125I]-3a and [125I]-6a were obtained in good radiochemical yield and high purity by treatment of 2a and 4a with [125I]NaI in the presence of H2O2 and chloroamine-T, respectively. Of the two isomeric iodovinyl derivatives 3 and 6, the 20Z isomer 6a exhibited the highest receptor binding affinity and the [125I]-6a gave the highest in vivo receptor-mediated target tissue uptake.
Structure-activity relationships of estrogenic ligands: synthesis and evaluation of (17.alpha.,20E)- and (17.alpha.,20Z)-21-halo-19-norpregna-1,3,5(10),20-tetraene-3,17.beta.-diols
作者:Elio Napolitano、Rita Fiaschi、Robert N. Hanson
DOI:10.1021/jm00113a012
日期:1991.9
affinity (RBA) for the estrogen receptor with use of a rat uterine preparation. The results demonstrated a marked difference between the E and Z isomers and among the halogen employed. The Z isomers possessed significantly higher RBA values and the larger halogens (I, Br) were more effective than the smaller Cl substituent. These results modify the previous interpretations of estrogen-receptor binding for
We identified a new estrogen receptor (ER)-targeting ligand with picomolar affinity serving as vehicle for radioiodines. This ligand is a potential radiotheranostics for ER+ male tumours.