estrogen receptor α (erα)

ERRα antagonist-1 (ERR+/- antagonist-1) is a high-affinity, selective antagonist of the estrogen-related receptor α (ERRα). It effectively prevents the interaction of ERRα with both Proliferator-activated Receptor γ Coactivator-1α (PGC-1α) and PGC-1β, displaying IC50 values of 170 nM and 180 nM, respectively. Notably, ERRα antagonist-1 does not interfere with the interactions involving ERRβ or ERRγ and the PGC-1α and PGC-1β coactivators. Furthermore, it does not affect the interaction between either ERα or ERβ and PGC-1α or SRC-1.

Alpha-Estradiol (Epiestradiol) is an estrogen that inhibits 5alpha-reductase and has potential in the study of androgenetic alopecia.

2-Hydroxyanthraquinone is an anthraquinone that has been found inSpermacoce latifoliaand has antibacterial and estrogenic activities.1,2It is active againstB. subtilisandB. cereus(MICs = 1.9 and 62.5 μg/ml, respectively).12-Hydroxyanthraquinone (19 μM) induces estrogen receptor α (ERα) activation in a yeast two-hybrid assay.2 1.Luo, Y., Shen, H.-Y., Shen, Q.-X., et al.A new anthraquinone and a new naphthoquinone from the whole plant of Spermacoce latifoliJ. Asian Nat. Prod. Res.19(9)869-876(2017) 2.Kurihara, R., Shiraishi, F., Tanaka, N., et al.Presence and estrogenicity of anthracene derivatives in coastal Japanese watersEnviron. Toxicol. Chem.24(8)1984-1993(2005)

Bisphenol Z is a bisphenol compound and high-performance monomer used in the production of advanced engineering plastics, resins, polycarbonates, optical films, and more. It exhibits antagonistic activity towards ERα (Estrogen receptor α) with an IC50 of 0.52 μM.

H3B-6545 is a selective estrogen receptor covalent antagonist (SERCA) that is orally available. As a novel class of ERα antagonists, H3B-6545 is used in the study of metastatic breast cancers, such as estrogen receptor-positive (ER), human epidermal growth factor receptor 2-negative (HER2-) breast cancer.

Ospemifene D4 is a deuterium labeled Ospemifene. Ospemifene is a selective and orally active modulator of estrogen receptor.

Propyl pyrazole triol (PPT) is a selective agonist of estrogen receptor alpha (ERα), exhibiting a relative binding affinity of 49% for ERα, which is approximately 410 times higher than its affinity for estrogen receptor beta (ERβ: 0.12%).

Estrone-N-O-C1-amido (ERα ligand 1) is an estrogen ligand derivative of Estrone that specifically binds to estrogen receptor α (ERα). With a linker, it complexes with the cIAP1 ligand Bestatin, forming SNIPER[1].

PROTAC ERα Degrader-2 is composed of a cIAP1 ligand binding group, a linker, and an estrogen receptor α (ERα) binding group, serving as an ERα degrader. It achieves maximal ERα degradation in human mammary tumor MCF7 cells at a concentration of 30 μM. Degradation inducers that utilize cIAP1 are referred to as specific and non-genetic IAP-dependent protein erasers (SNIPERs)[1].

SNIPER(ER)-87 is a chemical compound composed of a derivative of the inhibitor of apoptosis protein (IAP) ligand LCL161 conjugated to the estrogen receptor α (ERα) ligand 4-hydroxytamoxifen using a PEG linker. It effectively degrades the ERα protein with an IC50 value of 0.097 μM. Within cells, SNIPER(ER)-87 selectively recruits XIAP to ERα, and XIAP functions as the primary E3 ubiquitin ligase responsible for the degradation of ERα induced by SNIPER(ER)-87[1][2].

ERα degrader10 is a potent, selective, orally active estrogen receptor α (ERα) degrader. It demonstrates strong ERα binding affinity (IC50 of 24.0 nM) and degradation capability (EC50 of 5.3 nM). This compound degrades ERα through a proteasome-mediated pathway and is utilized in breast cancer research.

Erα-IN-1 (compound 3c) is an inhibitor of the estrogen receptor α (ERα), effectively blocking ERα activity in MCF7/ERE-LUC cells.

ERD-12310A targets the estrogen receptor α (ERα) as a PROTAC with an ED50 value of 47 pM and possesses oral bioavailability.

BAY-184 is a selective oral inhibitor of KAT6A and KAT6B with IC50 values of 71 nM and 83 nM, respectively. This compound suppresses estrogen receptor α (ERα) transcriptional activity and impedes cell proliferation across various breast cancer subtypes as well as tumor growth.

Tamoxifen-PEG-Clozapine is an estrogen receptor α (ERα) PROTAC degrader. It targets ERα for degradation through the ubiquitin-proteasome system by utilizing the E3 ubiquitin ligase component N-recognin 5. This compound is applicable in cancer research. (Pink: ERα inhibitor; Black: linker; Blue: CRBN Ligand)

ER covalent antagonist-1 (Compound 39D) acts as an antagonist of the estrogen receptor α (ERα). This compound inhibits the proliferation of ERα-positive MCF-7 cells with an IC50 of 0.98 μM, induces cell cycle arrest at the G0/G1 phase, and triggers apoptosis. Additionally, ER covalent antagonist-1 demonstrates antitumor activity in mouse models.

ERα degrader12 (Compound RA3) is an estrogen receptor alpha (ERα) degrader with antitumor properties. It significantly suppresses tumor growth in a xenograft mouse model of breast cancer.

PROTACERα Degrader-9 (Compound 18c) is a dual-targeting PROTAC degrader designed to diminish estrogen receptor α (ERα) and aromatase (ARO). It demonstrates a Ki of 0.25 μM for ERα binding and an IC50 of 4.6 μM for ARO inhibition. This compound curbs proliferation in wild-type MCF-7 cells (IC50=0.54 μM) and ERα mutant variants MCF-7EGFR (IC50=0.075 μM), MCF-7D538G (IC50=0.31 μM), and MCF-7Y537S (IC50=2.3 μM), while also downregulating ERS1 and MYC expression. PROTACERα Degrader-9 arrests the cell cycle at the G2/M phase and induces apoptosis in MCF-7 cells, exhibiting antitumor efficacy in mouse models.

Antiproliferative agent-51 (Compound 18h) inhibits estrogen receptor α (ERα)-mediated transcription with an IC50 of 1.6 nM. It also suppresses the proliferation of cancer cells ZR-75, with an IC50 of 0.031 μM, and exhibits antitumor activity in mouse models.

ERα degrader9 is a dual-targeting ligand designed for the estrogen receptor α (ERα) and aromatase (ARO). It can be utilized in the synthesis of PROTACERαDegrader-9.

EM-800 is a high affinity ligand for estrogen receptor-α (ERα), the prodrug of EM-652. EM-800 independently inhibited the growth of E1-stimulated ZR-75-1 xenograft tumors in nude mice.

17β-hydroxy Exemestane is the primary active metabolite of exemestane . It is formed by metabolism of exemestane by the cytochrome P450 (CYP) isoforms CYP1A and CYP4A11. 17β-hydroxy Exemestane is an aromatase inhibitor (IC50 = 69 nM using human placental microsomes) and an androgen receptor (AR) agonist (IC50 = 39.6 nM) that is selective for AR over estrogen receptor α (ERα; IC50 = 21.2 μM). It stimulates growth of AR- and ERα-positive MCF-7 (EC50 = 2.7 μM) and T47D breast cancer cells (EC50s = 0.43 and 1,500 nM for AR- and ER-mediated growth, respectively) and inhibits proliferation of testosterone-treated aromatase-overexpressing MCF-7aro cells in a concentration-dependent manner. 17β-hydroxy Exemestane (20 mg/kg) inhibits increases in serum cholesterol and LDL levels and prevents decreases in bone mineral density in the lumbar vertebrae and femur, as well as femoral bending strength and compressive strength of the fifth lumbar vertebrae, in ovariectomized rats.

Zearalenone-13C18is intended for use as an internal standard for the quantification of zearalenone by GC- or LC-MS. Zearalenone is a mycotoxin that has been found inFusariumand has estrogenic activities.1It binds to human estrogen receptor α (ERα) and ERβ (IC50s = 9 and 5.8 nM, respectively).2Zearalenone induces precocious development of mammary tissues in young female pigs and prepucial enlargement in young male pigs.3Zearalenone (1.5-5 mg/kg of diet) induces hyperestrogenism in pigs. It also induces degeneration of meiotic chromatin in oocytes and reduces fertility in pigs when administered at a dose of 200 μg/kg.4Zearalenone has been found as a contaminant in wheat, maize, and barley and livestock feeds.3,4

17-Epiestriol is a metabolite of estrone .1It is formed from estroneviaa 16α-hydroxy estrone intermediate by reduction of the C-17 ketone. 17-Epiestriol binds to estrogen receptor α (ERα) and ERβ with relative binding affinities of 29 and 80 compared with 17β-estradiol .2 1.Brinton, L.A., Trabert, B., Anderson, G.L., et al.Serum estrogens and estrogen metabolites and endometrial cancer risk among postmenopausal womenCancer Epidemiol. Biomarkers Prev.25(7)1081-1089(2016) 2.Kuiper, G.G.J.M., Lemmen, J.G., Carlsson, B., et al.Interaction of estrogenic chemicals and phytoestrogens with estrogen receptor βEndocrinology139(10)4252-4263(1998)