Ebopiprant (OBE-022) is a first-in-class, potent, orally bioavailable and selective prostaglandin F2α (PGF2α) receptor antagonist, with Kis of 1 nM, 26 nM for human and rat FP receptors, respectively. It was designed to control preterm labour by reducing inflammation and uterine contractions as well as preventing cervical changes and fetal membrane rupture without causing the potentially serious vasoconstriction in the foetus.

Physicochemical Properties

Molecular Formula	C30H34FN3O5S2
Molecular Weight	599.736468791962
Exact Mass	599.192
CAS #	2005486-31-5
Related CAS #	2005486-31-5;2005486-32-6 (HCl);2005486-34-8 (fumarate);2005486-33-7 (sulfate); 2005486-42-8; 2005486-37-1 (citrate); 2005486-38-2 (esylate);
PubChem CID	122522051
Appearance	White to light yellow solid powder
LogP	4.9
Hydrogen Bond Donor Count	2
Hydrogen Bond Acceptor Count	9
Rotatable Bond Count	12
Heavy Atom Count	41
Complexity	956
Defined Atom Stereocenter Count	3
SMILES	S(C1C=CC(C2C=CC=CC=2)=CC=1)(N1CCS[C@H]1C(N[C@H](C1C=CC(=CC=1)F)CCOC([C@H](C(C)C)N)=O)=O)(=O)=O
InChi Key	UUIBKACUTXYSAK-YCVJPRETSA-N
InChi Code	InChI=1S/C30H34FN3O5S2/c1-20(2)27(32)30(36)39-18-16-26(23-8-12-24(31)13-9-23)33-28(35)29-34(17-19-40-29)41(37,38)25-14-10-22(11-15-25)21-6-4-3-5-7-21/h3-15,20,26-27,29H,16-19,32H2,1-2H3,(H,33,35)/t26-,27-,29-/m0/s1
Chemical Name	[(3S)-3-(4-fluorophenyl)-3-[[(2S)-3-(4-phenylphenyl)sulfonyl-1,3-thiazolidine-2-carbonyl]amino]propyl] (2S)-2-amino-3-methylbutanoate
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	Using HEK293 cells that were transfected with the FP receptor and subjected to a competitive binding experiment with 3H-PGF2α, the FP binding affinity of Ebopiprant (OBE022) and OBE002 was ascertained. OBE022 has binding affinities (Ki) of 1 nM for human and 26 nM for rat FP receptors, respectively. The Ki values for OBE002 are 6 nM for the human FP receptor and 313 nM for the rat FP receptor. OBE022 and OBE002 bind reversibly and competitively because, when the concentration of either compound is increased, the slope of the binding curve continuously decreases. This is consistent with an increase in the equilibrium dissociation constant (KD) without a corresponding decrease in receptor density [1].
ln Vivo	Time course of cumulative percent delivery in mice treated with OBE022, nifedipine, or vehicle following RU486-induced GD17 preterm birth. An oral OBE022 medication postponed the RU486-induced preterm labor, as evidenced by a shift to the right in the percent labor curve. Oral therapy is equally efficacious as nifedipine. The duration until the first pup delivery increased in both OBE022 and nifedipine. One significant outcome of the longer gestation period is that the mother rat can give birth to healthy pups. When compared to OBE022 or nifedipine alone, there was a more noticeable shift to the right in the percentage labor curve, indicating that the combination of the two medications worked synergistically to postpone RU486-induced preterm labor. Furthermore, a significant increase in the first pup's birth time was noted [1].
References	[1]. OBE022, an oral and selective prostaglandin F2α receptor antagonist as an effective and safe modality for the treatment of preterm labor. J Pharmacol Exp Ther. 2018 Aug;366(2):349-364.
Additional Infomation	Ebopiprant is under investigation in clinical trial NCT03369262 (Poc Study of OBE022 in Threatened Preterm Labour).

Solubility Data

Solubility (In Vitro)

DMSO : ~250 mg/mL (~416.85 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 2.08 mg/mL (3.47 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 20.8 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: 2.08 mg/mL (3.47 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 20.8 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: ≥ 2.08 mg/mL (3.47 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 20.8 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	1.6674 mL	8.3369 mL	16.6739 mL
	5 mM	0.3335 mL	1.6674 mL	3.3348 mL
	10 mM	0.1667 mL	0.8337 mL	1.6674 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.