Electrophilic Affinity Labels and Fluorescent Conjugates for the Estrogen Receptor (Norhexestrol, Aziridine, Hexestrol, Fluorescein, Alkylator)

We prepared several aziridine derivatives of the potent, non-steroidal estrogen hexestrol ((3R*,4S*)-3,4-bis(4-hydroxyphenyl)hexane)) in search of an estrogen agonist that achieves selective, efficient labeling of the estrogen receptor. The electrophilic agent, aziridine, was positioned at a side chain terminus which was linked to the bis-phenol binding component of hexestrol by various functionalities: ketone, ester, thioether, or methylene chain. The apparent competitive binding affinity of these derivatives for the estrogen receptor ranges from 1.8-25% of that of estradiol. Most of the norhexestrol aziridine derivatives bind to the receptor in a time-dependent, irreversible manner; however, the rate and efficiency of this binding varies widely with relatively small structural changes. This is consistent with the irreversible attachment requiring a precise alignment of activating and reacting residues in the binding site of the receptor. Nearly all of the norhexestrol aziridine derivatives retained the estrogenic activity of the parent hexestrol ligand as determined in human breast cancer cell growth experiments (MCF-7 cell line). Norhexestrol aziridine 34 ((6R*,7S*)-1-(N-aziridinyl)-6,7-bis(4-hydroxyphenyl)-5-nonanone) had the most potential as an estrogenic affinity labeling agent because of its agonistic properties, and its rapid, efficient irreversible binding to the receptor. Therefore, norhexestrol aziridine 34 was prepared in tritium labeled form (specific activity = 67 Ci/mmol), and was found to be an efficient, selective estrogenic affinity label of the estrogen receptor with 60% of the receptor labeled within 2 hours (55% selectivity, Az / ER , 12 nM/2 nM, lamb uterine cytosolic receptor).

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Chemistry

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Zablocki, Jeffery Alan

• Chemistry, Organic

Identifier

(UMI)AAI8701665

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/70357