Fluorine-18-labeled estrogens, progestins and corticosteroids for receptor-based imaging of breast tumors and target areas of the brain
Pomper, Martin Gilbert
This item is only available for download by members of the University of Illinois community. Students, faculty, and staff at the U of I may log in with your NetID and password to view the item. If you are trying to access an Illinois-restricted dissertation or thesis, you can request a copy through your library's Inter-Library Loan office or purchase a copy directly from ProQuest.
Permalink
https://hdl.handle.net/2142/19008
Description
Title
Fluorine-18-labeled estrogens, progestins and corticosteroids for receptor-based imaging of breast tumors and target areas of the brain
Author(s)
Pomper, Martin Gilbert
Issue Date
1989
Department of Study
Chemistry
Discipline
Chemistry
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
Ph.D.
Degree Level
Dissertation
Keyword(s)
Organic Chemistry
Pharmaceutical Chemistry
Health Sciences
Radiology
Language
eng
Abstract
Estrogens can be labeled with the positron-emitting radionuclide fluorine-18 (t$\sb{1/2}$ = 110 min) by fluoride ion (n-Bu$\sb4$N$\sp{18}$F) displacement of a 16$\beta$-trifluoromethanesulfonate (triflate) derivative of the corresponding estrone 3-triflate, and purification by HPLC. That sequence has been used to synthesize the 11$\beta$-methoxy 1 and 11$\beta$-ethyl 2 analogues of the breast tumor imaging agent, 16$\alpha$-($\sp{18}$F) fluoro-17$\beta$-estradiol (FES). Tissue distribution studies of 1 and 2 in immature female rats show high selectivity for target tissue (T, uterus) vs non-target (NT, muscle and lung), with T/NT ratios being 43 and 17 at one hour after injection for 1 and 2, respectively. The parent estrogen FES has previously been shown to display an intermediate value for tissue selectivity.
The progestin 21-($\sp{18}$F) fluoro-16$\alpha$-ethyl-19-norprogesterone (FENP), synthesized from the 21-triflate precursor, is a high affinity ligand for the progestin receptor, and in vivo, exhibits highly selective uptake by the uterus of estrogen-primed rats. Respective T/NT ratios of 16 and 41 at one and 3 hours after injection have been demonstrated. Two epimeric (at C-21) analogues of the high affinity progestin promegestone (R 5020) were prepared in fluorine-18 labeled form from the corresponding triflate precursors; while 21S-($\sp{18}$F) R 5020 3 showed a T/NT ratio of 4 at 3 hours after injection, 21R-($\sp{18}$F) R 5020 4 showed no selective uptake. Compounds 3 and 4 each suffered extensive in vivo defluorination.
Derivatives of the high affinity Type I and Type II corticosteroid receptor ligands RU 26752 and RU 28362, respectively, were prepared in fluorine-18 labeled form from the corresponding 3$\sp\prime$-methanesulfonates. Neither labeled compound showed selective target tissue (brain) uptake and each underwent substantial in vivo defluorination. 1,2-($\sp3$H$\sb2$) RU 26752 was also synthesized (52 Ci/mmol) as a potential Type I receptor probe.
These fluorine-18 labeled steroids can be prepared within 2 hours of the end of bombardment, and their specific activities range from 500-4000 Ci/mmol. The high target tissue selectivities and uterine uptake values for 1, 2 and FENP suggest that these compounds may be useful for in vivo imaging of estrogen and progestin target tissues and tumors (such as human breast tumors) by positron emission tomography.
Use this login method if you
don't
have an
@illinois.edu
email address.
(Oops, I do have one)
IDEALS migrated to a new platform on June 23, 2022. If you created
your account prior to this date, you will have to reset your password
using the forgot-password link below.