Methodology for the synthesis and specific activity determination of 16 alpha-[77Br]-bromoestradiol-17 beta and 16 alpha-[77Br]-11 beta-methoxyestradiol-17 beta, two estrogen receptor-binding radiopharmaceuticals

Int J Appl Radiat Isot. 1982 Jul;33(7):545-51. doi: 10.1016/0020-708x(82)90010-2.

Abstract

16 alpha-[77 Br]-Bromoestradiol-17 beta (3a) has been synthesized from estrone enol diacetate (1) by bromination with Na77Br and hydrogen peroxide-acetic acid, followed by reduction with lithium aluminum hydride to give a mixture of 16 alpha-[77 Br]-bromoestradiol-17 beta (3a) and 16 alpha-[77Br]-bromoestradiol-17 alpha (3b) from which the desired epimer (3a) can be obtained in 50% overall radiochemical yield (from Na77Br) by HPLC. Analogous procedures can be used in the preparation of 16 alpha-[77Br]-bromo-11 beta-methoxyestradiol-17 beta. (4a) The effective specific activities of these radiopharmaceuticals, determined by binding to the uterine estrogen receptor, are 900-1500 Ci/mmol. Both have affinity and good binding selectivity for the estrogen receptor and are useful as imaging agents for mammary tumors.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Bromine*
  • Estradiol / analogs & derivatives*
  • Estradiol / chemical synthesis
  • Female
  • Isotope Labeling
  • Neoplasms, Hormone-Dependent / diagnostic imaging
  • Protein Binding
  • Radioisotopes*
  • Radionuclide Imaging
  • Receptors, Estrogen / metabolism*
  • Sheep
  • Uterus / metabolism

Substances

  • Radioisotopes
  • Receptors, Estrogen
  • Estradiol
  • 16 alpha-bromo-17 beta-estradiol
  • 16 alpha-bromo-11 beta-methoxy-17 beta-estradiol
  • Bromine