EIDD-2749 (4'-Fluorouridine) is an orally bioavailable RdRp inhibitor. EIDD-2749 can effectively inhibit the replication of RSV and SARS-CoV-2. EIDD-2749 also displays activity against HCV (hepatitis C virus) and lymphocytic choriomeningitis virus (LCMV). EIDD-2749 is a promising oral research candidate for COVID-19 and is also suitable for research on other RNA viruses.

Physicochemical Properties

Molecular Formula	C9H11FN2O6
Molecular Weight	262.19
Exact Mass	262.06
CAS #	1613589-24-4
PubChem CID	54260440
Appearance	Off-white to yellow solid powder
Density	1.77±0.1 g/cm3(Predicted)
LogP	-2
Hydrogen Bond Donor Count	4
Hydrogen Bond Acceptor Count	7
Rotatable Bond Count	2
Heavy Atom Count	18
Complexity	416
Defined Atom Stereocenter Count	4
SMILES	C1=CN(C(=O)NC1=O)[C@H]2[C@@H]([C@@H]([C@](O2)(CO)F)O)O
InChi Key	RDCYLPRXPILMRP-JVZYCSMKSA-N
InChi Code	InChI=1S/C9H11FN2O6/c10-9(3-13)6(16)5(15)7(18-9)12-2-1-4(14)11-8(12)17/h1-2,5-7,13,15-16H,3H2,(H,11,14,17)/t5-,6+,7-,9-/m1/s1
Chemical Name	1-[(2R,3R,4S,5S)-5-fluoro-3,4-dihydroxy-5-(hydroxymethyl)oxolan-2-yl]pyrimidine-2,4-dione
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

Targets	RdRp, RSV,SARS-CoV-2, HCV, COVID-19, LCMV[1][2][3].
ln Vitro	EIDD-2749 causes RSV and SARS-CoV-2 RdRP to stop the synthesis of phosphodiester bonds later than expected[1]. In disease-relevant, well-differentiated HAE cells, EIDD-2749 is quickly anabolized, metabolically stable, and potently antiviral[1]. Compared to HEp-2 cells, EIDD-2749 has an anti-RSV potency that is approximately 17 times more potent. Despite this, the low cytotoxicity levels (CC50 169 mM) remain unchanged, resulting in a high SI (SI = EC50/CC50) of approximately 1877[1]. EIDD-2749 has an EC50 value between 0.2 and 0.6 M, which suppresses SARS-CoV-2[2]. EIDD-2749 exhibits stability in human plasma, cytotoxicity with a CC50 of 380 μM, and an EC50 of 1.86 μM in the Vero E6 cell line[3].
ln Vivo	In an RSV infection mouse model, EIDD-2749 (0.2, 1, 5 mg/kg; po; once daily for 4 days) exhibits good oral efficacy in a dose-dependent manner[1]. In comparison to molnupiravir given twice daily in vivo, EIDD-2749 exhibits high efficacy against SARS-CoV-2 infection and can be delivered as a single daily dose[2].
Animal Protocol	Animal/Disease Models: Balb/cJ mice (RSV infection model )[1]. Doses: 0.2, 1, 5 mg/kg Route of Administration: Oral administration; single daily for 4 days Experimental Results: Resulted in a statistically significant reduction in lung virus load.
References	[1]. 4'-Fluorouridine is an oral antiviral that blocks respiratory syncytial virus and SARS-CoV-2 replication. Science. 2022 Jan 14;375(6577):161-167. [2]. 4’-fluorouridine and its derivatives as potential COVID-19 oral drugs: a review [version 1; peer review: 1 approved with reservations, 1 not approved]. F1000Research 2022, 11:410. [3]. 4'-halogen containing nucleotide and nucleoside therapeutic compositions and uses related thereto. Patent WO2019173602A1.

Solubility Data

Solubility (In Vitro)

H2O : 62.5 mg/mL (238.38 mM) DMSO : 25 mg/mL (95.35 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 25 mg/mL (95.35 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 250.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly. Solubility in Formulation 2: ≥ 2.5 mg/mL (9.54 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 25.0 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 3: ≥ 2.5 mg/mL (9.54 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in 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 25.0 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.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	3.8140 mL	19.0701 mL	38.1403 mL
	5 mM	0.7628 mL	3.8140 mL	7.6281 mL
	10 mM	0.3814 mL	1.9070 mL	3.8140 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.