Prinaberel, formerly known as ERB-041, is a biochemical which acts as a highly selective agonist of the ERβ subtype of the estrogen receptor. It is used in scientific research to elucidate the role of the ERβ receptor. Studies have indicated that selective ERβ agonists like prinaberel could be useful in the clinical treatment of a variety of medical conditions including inflammatory bowel disease, rheumatoid arthritis, endometriosis, and sepsis. Accordingly, prinaberel either was or still is under investigation by Wyeth for the treatment of some of these conditions.

Physicochemical Properties

Molecular Formula	C15H10FNO3
Molecular Weight	271.24
Exact Mass	271.064
CAS #	524684-52-4
Related CAS #	524684-52-4;
PubChem CID	656954
Appearance	White to gray solid powder
Density	1.4±0.1 g/cm3
Boiling Point	451.6±45.0 °C at 760 mmHg
Melting Point	250-252ºC
Flash Point	226.9±28.7 °C
Vapour Pressure	0.0±1.1 mmHg at 25°C
Index of Refraction	1.695
LogP	3.97
Hydrogen Bond Donor Count	2
Hydrogen Bond Acceptor Count	5
Rotatable Bond Count	2
Heavy Atom Count	20
Complexity	367
Defined Atom Stereocenter Count	0
InChi Key	MQIMZDXIAHJKQP-UHFFFAOYSA-N
InChi Code	InChI=1S/C15H10FNO3/c1-2-8-5-10(18)7-12-14(8)20-15(17-12)9-3-4-13(19)11(16)6-9/h2-7,18-19H,1H2
Chemical Name	2-(3-fluoro-4-hydroxyphenyl)-7-vinylbenzo[d]oxazol-5-ol
Synonyms	ERB041 ERB 041 ERB041 Prinaberel WAY-202041 WAY202041 WAY 202041
HS Tariff Code	2934.99.9001
Storage	Powder-20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month
Shipping Condition	Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Biological Activity

ln Vitro	Prinaberel (ERB-041) (0-60 µM; 24 hours) treatment of human SCC cells results in reduced colony formation, cell differentiation, and cell cycle arrest [2]. In A431 cells, prinaberel significantly decreased the expression of inflammatory regulatory proteins as p-NFκBp65, iNOS, and COX-2. Phosphorylated PI3K and AKT are decreased by prinaberel, which is linked to increased E-cadherin expression and decreased A431 cell motility [2]. Cell growth is inhibited by prinaberel (0.01-10 µM) in a dose- and time-dependent manner [3]. Prinaberel (10 µM; 48 hours) induces ovarian cancer (SKOV-3 cells) to undergo apoptosis [3].
ln Vivo	In SKH-1 hairless mice, the topical drug prinaberel (2 mg/mouse; 30 minutes prior to UVB irradiation for 30 weeks) prevents the growth of squamous cell carcinoma [2]. Prinaberel causes apoptosis and inhibits UVB-induced proliferation and angiogenesis in skin cancers. In skin cancers caused by UVB radiation, prinaberel suppresses pro-inflammatory signaling pathways. Plinabiber inhibits WNT signaling and the PI3K-AKT pathway to reduce tumor invasiveness [2].
Cell Assay	Western Blot Analysis[2] Cell Types: A431 Cell Tested Concentrations: 0, 20, 40 and 60 µM Incubation Duration: 24 hrs (hours) Experimental Results: diminished expression of G1 cyclins (D1, D2 and D3) and CDK4. Cell proliferation assay[3] Cell Types: SKOV-3, A2780CP or OVCAR-3 Cell Tested Concentrations: 0.01, 0.1 and 10 µM Incubation Duration: 24-48 hrs (hours) Experimental Results: Significant inhibitory effect on cell proliferation.
Animal Protocol	Animal/Disease Models: Six to eight week old SKH-1 hairless female mice [2] Doses: 2 mg/mouse in 200 µl ethanol UVB (180mJ/cm2) 30 minutes before irradiation for 30 weeks Experimental Results: SKH -1 diminished UVB-induced skin tumor development in hairless mice.
References	[1]. Design and synthesis of aryl diphenolic azoles as potent and selective estrogen receptor-beta ligands. J Med Chem. 2004;47(21):5021-5040. [2]. Erb-041, an estrogen receptor-β agonist, inhibits skin photocarcinogenesis in SKH-1 hairless mice by downregulating the WNT signaling pathway. Cancer Prev Res (Phila). 2014;7(2):186-198. [3]. Estrogen receptor modulators genistein, daidzein and ERB-041 inhibit cell migration, invasion, proliferation and sphere formation via modulation of FAK and PI3K/AKT signaling in ovarian cancer. Cancer Cell Int. 2018;18:65. Published 2018.
Additional Infomation	Prinaberel is an estrogen receptor beta agonist.

Solubility Data

Solubility (In Vitro)

DMSO : ≥ 40 mg/mL (~147.47 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 5 mg/mL (18.43 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 50.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL. Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution. Solubility in Formulation 2: 5 mg/mL (18.43 mM) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), suspension solution; with ultrasonication. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 50.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly. Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution. Solubility in Formulation 3: ≥ 5 mg/mL (18.43 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 50.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	3.6868 mL	18.4339 mL	36.8677 mL
	5 mM	0.7374 mL	3.6868 mL	7.3735 mL
	10 mM	0.3687 mL	1.8434 mL	3.6868 mL

*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.