Baloxavir (Synonyms: Baloxavir acid; S-033447)

Name: Baloxavir
Brand: MedChemExpress
SKU: HY-109025A
Rating: 5.0 (46 reviews)

Cat. No.: HY-109025A Purity: 99.82% ee.: 100.00%: Data Sheet
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Baloxavir (Baloxavir acid), derived from the proagent Baloxavir marboxil, is a first-in-class, potent and selective cap-dependent endonuclease (CEN) inhibitor within the polymerase PA subunit of influenza A and B viruses. Baloxavir inhibits viral RNA transcription and replication and has potently antiviral activity.

For research use only. We do not sell to patients.

CAS No. : 1985605-59-1

Size	Stock	Quantity
Solid + Solvent (Highly Recommended)
10 mM * 1 mL in DMSO ready for reconstitution	In-stock	Estimated Time of Arrival: December 31
Solution
10 mM * 1 mL in DMSO	In-stock	Estimated Time of Arrival: December 31
Solid
5 mg	In-stock	Estimated Time of Arrival: December 31
10 mg	In-stock	Estimated Time of Arrival: December 31
25 mg	In-stock	Estimated Time of Arrival: December 31
50 mg	In-stock	Estimated Time of Arrival: December 31
100 mg	In-stock	Estimated Time of Arrival: December 31
200 mg	Get quote
500 mg	Get quote

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Customer Review

Based on 46 publication(s) in Google Scholar

Other Forms of Baloxavir:

Baloxavir marboxil In-stock
Baloxavir-d₄ In-stock
Baloxavir-d₅ Get quote
Baloxavir-d₁ Get quote
Baloxavir (Standard) Get quote

46 Publications Citing Use of MCE Baloxavir

Cell Proliferation/Viability Assay

IHC

RT-PCR

: Baloxavir purchased from MedChemExpress. Usage Cited in: Acta Pharm Sin B. 2025 Aug;15(8):4156-4173.; Baloxavir-resistant WSN strains that had been passaged 40 times in the presence of baloxavir, with an EC₅₀ of 1.04 μmol/L

: Baloxavir purchased from MedChemExpress. Usage Cited in: Emerg Microbes Infect. 2025 Dec;14(1):2564308. [Abstract]; Susceptibility of influenza D and A viruses to anti-influenza drugs. Drug susceptibility profiles of baloxavir were assessed using a viral yield reduction assay in MDCK cells. Cells were infected with IDV and IAV (MOI = 0.1), followed by removal of the virus inoculum and treatment with serially diluted drugs. Supernatants were collected at designated timepoints post-infection for TCID50 titration. Antiviral activity (%) was calculated relative to virus-free and drug-free controls.

: Baloxavir purchased from MedChemExpress. Usage Cited in: Front Immunol. 2025 Mar 17:16:1532336. [Abstract]; After infection of MDCK cells with H1N1-UI182 at an MOI of 0.01, the cells were treated with Quercetin (10 µM), Taxifolin (50 µM), Miquelianin (100 µM), and Baloxavir (10 µM) for 48 h. Nuclei were stained with DAPI, and infected cells were detected by NP-specific immunofluorescence staining (scale bar: 100 µm).

: Baloxavir purchased from MedChemExpress. Usage Cited in: Int J Mol Sci. 2025 Jun 3;26(11):5358.; B/Jifang/13/97. MDCK cells were infected with IAV or IBV at an MOI of 0.02 for 2 h and then treated with lycorine, Bal (Baloxavir), and OC. AH was added during infection. Total RNA was extracted, and the IAV M2 or IBV HA mRNA levels were quantified using qRT-PCR.

: Baloxavir purchased from MedChemExpress. Usage Cited in: Influenza Other Respir Viruses. 2025 Oct;19(10):e70176. [Abstract]; Seven strains were selected from a total of 41 seasonal strains that showed high viral activity during oseltamivir treatment. The EC50 was compared to the reference H1N1 (A/Hong Kong/415742/09).

: Baloxavir purchased from MedChemExpress. Usage Cited in: Front Pharmacol. 2019 Oct 16;10:1203. [Abstract]; Cell viability as a percentage of the control cell (treated with DMSO for T-705 or PBS for BXA) viability in uninfected Vero E6 cells incubated for 72 h post-T-705 (Favipiravir)/BXA (Baloxavir) treatment. Each point represents the mean and SD of three independent experiments.

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Biological Activity
Purity & Documentation
References
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Description

IC₅₀ & Target

Influenza virus^[1] Cap-dependent endonuclease (CEN)^[1]^[2]

Cellular Effect

Cell Line	Type	Value	Description	References
HEK-293T	CC₅₀	63.09 μM Compound: 5; BXA	Cytotoxicity against human HEK293T cells assessed as reduction in cell viability incubated for 48 hrs by CCK-8 assay Cytotoxicity against human HEK293T cells assessed as reduction in cell viability incubated for 48 hrs by CCK-8 assay	[PMID: 38775356]
HEK-293T	EC₅₀	0.004 μM Compound: 5; BXA	Anti-influenza activity against Influenza A virus A/WSN/33(H1N1) infected in HEK293T cells assessed as reduction in virus-induced cytopathic effect incubated for 48 hrs by CCK-8 assay Anti-influenza activity against Influenza A virus A/WSN/33(H1N1) infected in HEK293T cells assessed as reduction in virus-induced cytopathic effect incubated for 48 hrs by CCK-8 assay	[PMID: 38775356]
HEK-293T	EC₅₀	0.005 μM Compound: 5; BXA	Anti-influenza activity against Influenza A virus H3N2 infected in HEK293T cells assessed as reduction in virus-induced cytopathic effect incubated for 48 hrs by CCK-8 assay Anti-influenza activity against Influenza A virus H3N2 infected in HEK293T cells assessed as reduction in virus-induced cytopathic effect incubated for 48 hrs by CCK-8 assay	[PMID: 38775356]
HEK-293T	EC₅₀	0.006 μM Compound: 5; BXA	Anti-influenza activity against Influenza B virus Victoria/2/87 infected in HEK293T cells assessed as reduction in virus-induced cytopathic effect incubated for 48 hrs by CCK-8 assay Anti-influenza activity against Influenza B virus Victoria/2/87 infected in HEK293T cells assessed as reduction in virus-induced cytopathic effect incubated for 48 hrs by CCK-8 assay	[PMID: 38775356]
HEK-293T	EC₅₀	0.071 μM Compound: 5; BXA	Anti-influenza activity against Influenza B virus Yamagata/16/88 infected in HEK293T cells assessed as reduction in virus-induced cytopathic effect incubated for 48 hrs by CCK-8 assay Anti-influenza activity against Influenza B virus Yamagata/16/88 infected in HEK293T cells assessed as reduction in virus-induced cytopathic effect incubated for 48 hrs by CCK-8 assay	[PMID: 38775356]
MDCK	CC₅₀	20 μM Compound: Baloxavir acid	Cytotoxicity in MDCK cells assessed as reduction in cell viability incubated for 12 hrs by MTT assay Cytotoxicity in MDCK cells assessed as reduction in cell viability incubated for 12 hrs by MTT assay	[PMID: 31536340]
MDCK	CC₅₀	28.79 μM Compound: Baloxavir	Cytotoxicity against MDCK cells assessed as decrease in survival rate Cytotoxicity against MDCK cells assessed as decrease in survival rate	[PMID: 38964259]
MDCK	CC₅₀	30.9 μM Compound: 5; BXA	Cytotoxicity against dog MDCK cells assessed as reduction in cell viability incubated for 48 hrs by CCK-8 assay Cytotoxicity against dog MDCK cells assessed as reduction in cell viability incubated for 48 hrs by CCK-8 assay	[PMID: 38775356]
MDCK	CC₅₀	5.6 μM Compound: 3; BXA	Cytotoxicity against MDCK cells assessed as reduction in cell viability by CellTiter-Glo assay Cytotoxicity against MDCK cells assessed as reduction in cell viability by CellTiter-Glo assay	[PMID: 32787099]
MDCK	CC₅₀	9.56 μM Compound: BXA	Cytotoxicity against dog MDCK cells assessed as reduction in cell viability incubated for 48 hrs by celltiter-glo assay Cytotoxicity against dog MDCK cells assessed as reduction in cell viability incubated for 48 hrs by celltiter-glo assay	[PMID: 37354741]
MDCK	CC₅₀	> 100 μM Compound: BXA	Cytotoxicity against MDCK cells incubated for 48 hrs by MTT assay Cytotoxicity against MDCK cells incubated for 48 hrs by MTT assay	[PMID: 36521178]
MDCK	EC₅₀	0.9 nM Compound: 3; BXA	Antiviral activity against Influenza A/California/04/2009 (H1N1)pdm09 infected in MDCK cells assessed as protection against virus-induced cell death by CellTiter-Glo assay Antiviral activity against Influenza A/California/04/2009 (H1N1)pdm09 infected in MDCK cells assessed as protection against virus-induced cell death by CellTiter-Glo assay	[PMID: 32787099]
NIH3T3	CC₅₀	> 800 μM Compound: Baloxavir acid	Cytotoxicity in mouse NIH/3T3 cells assessed as reduction in cell viability incubated for 12 hrs by MTT assay Cytotoxicity in mouse NIH/3T3 cells assessed as reduction in cell viability incubated for 12 hrs by MTT assay	[PMID: 31536340]

In Vitro

The median EC₅₀ values at baseline for Baloxavir (BXA) are 17.96 nM for A/H1N1pdm, 4.48 nM for A/H3N2, and 18.67 nM for type B virus^[1].
Baloxavir (BXA) inhibits viral RNA transcription via selective inhibition of cap-dependent endonuclease (CEN) activity in enzymatic assays, and inhibits viral replication in infected cells without cytotoxicity in cytopathic effect assays. Baloxavir shows broad potency against various subtypes of influenza A viruses (H1N2, H5N1, H5N2, H5N6, H7N9 and H9N2). Additionally, serial passages of the viruses in the presence of Baloxavir result in isolation of PA/I38T variants with reduced BXA susceptibility^[2].
Baloxavir (BXA) inhibits cap-dependent endonuclease (CEN) and CEN/RdRp activities with IC₅₀ values of 2.5 nM and 1.6 nM, respectively, while low potency (IC₅₀ >40 nM) is observed against RdRp activity^[2].
Baloxavir (BXA) has a high inhibitory potency against CEN activity of the tested viral ribonucleoprotein complexes (vRNPs) from influenza A and B viruses with mean IC₅₀ values of 1.4-3.1 nM and 4.5-8.9 nM, respectively, indicating that Baloxavir has broad spectrum activities. Baloxavir shows high potency against influenza A and B viruses with mean EC₉₀ of 0.46 - 0.98 nM and 2.2-3.4 nM, respectively^[2].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

Clinical Trial

Molecular Weight

483.49

Formula

C₂₄H₁₉F₂N₃O₄S

CAS No.

1985605-59-1

Appearance

Solid

Color

White to yellow

SMILES

O=C1N2[C@](COCC2)([H])N([C@@H]3C4=CC=CC=C4SCC5=C(F)C(F)=CC=C35)N6C1=C(O)C(C=C6)=O

Shipping

Room temperature in continental US; may vary elsewhere.

Storage

4°C, stored under nitrogen

*In solvent : -80°C, 1 year; -20°C, 6 months (stored under nitrogen)

Solvent & Solubility

In Vitro:

DMSO : 41.18 mg/mL (85.17 mM; ultrasonic and warming and heat to 60°C; Hygroscopic DMSO has a significant impact on the solubility of product, please use newly opened DMSO)

Preparing
Stock Solutions

Concentration Solvent Mass	1 mg	5 mg	10 mg

1 mM	2.0683 mL	10.3415 mL	20.6830 mL
5 mM	0.4137 mL	2.0683 mL	4.1366 mL
10 mM	0.2068 mL	1.0341 mL	2.0683 mL

View the Complete Stock Solution Preparation Table

* Please refer to the solubility information to select the appropriate solvent. Once prepared, please aliquot and store the solution to prevent product inactivation from repeated freeze-thaw cycles.
Storage method and period of stock solution: -80°C, 1 year; -20°C, 6 months (stored under nitrogen). When stored at -80°C, please use it within 1 year. When stored at -20°C, please use it within 6 months.

Molarity Calculator
Dilution Calculator

Mass (g) = Concentration (mol/L) × Volume (L) × Molecular Weight (g/mol)

Concentration _(start) × Volume _(start) = Concentration _(final) × Volume _(final)

This equation is commonly abbreviated as: C₁V₁ = C₂V₂

Concentration _(start)

Volume _(start)

Concentration _(final)

Volume _(final)

In Vivo:

Select the appropriate dissolution method based on your experimental animal and administration route.

For the following dissolution methods, please ensure to first prepare a clear stock solution using an In Vitro approach and then sequentially add co-solvents:
To ensure reliable experimental results, the clarified stock solution can be appropriately stored based on storage conditions. As for the working solution for in vivo experiments, it is recommended to prepare freshly and use it on the same day.
The percentages shown for the solvents indicate their volumetric ratio in the final prepared solution. If precipitation or phase separation occurs during preparation, heat and/or sonication can be used to aid dissolution.

Protocol 1

Add each solvent one by one: 10% DMSO 40% PEG300 5% Tween-80 45% Saline
Solubility: ≥ 2.08 mg/mL (4.30 mM); Clear solution

This protocol yields a clear solution of ≥ 2.08 mg/mL (saturation unknown).
Taking 1 mL working solution as an example, add 100 μL DMSO stock solution (20.8 mg/mL) to 400 μL PEG300, and mix evenly; then add 50 μL Tween-80 and mix evenly; then add 450 μL Saline to adjust the volume to 1 mL.
Preparation of Saline: Dissolve 0.9 g sodium chloride in ddH₂O and dilute to 100 mL to obtain a clear Saline solution.
Protocol 2

Add each solvent one by one: 10% DMSO 90% Corn Oil
Solubility: ≥ 2.08 mg/mL (4.30 mM); Clear solution

This protocol yields a clear solution of ≥ 2.08 mg/mL (saturation unknown). If the continuous dosing period exceeds half a month, please choose this protocol carefully.
Taking 1 mL working solution as an example, add 100 μL DMSO stock solution (20.8 mg/mL) to 900 μL Corn oil, and mix evenly.

In Vivo Dissolution Calculator

Please enter the basic information of animal experiments:

Dosage

mg/kg

Animal weight
(per animal)

Dosing volume
(per animal)

μL

Number of animals

Recommended: Prepare an additional quantity of animals to account for potential losses during experiments.

Please enter your animal formula composition:

DMSO +

Tween-80 +

Saline

Recommended: Keep the proportion of DMSO in working solution below 2% if your animal is weak.

The co-solvents required include: DMSO, . All of co-solvents are available by MedChemExpress (MCE). , Tween 80. All of co-solvents are available by MedChemExpress (MCE).

Calculation results:

Working solution concentration: mg/mL

Method for preparing stock solution: mg drug dissolved in μL DMSO (Stock solution concentration: mg/mL).

*In solvent : -80°C, 1 year; -20°C, 6 months (stored under nitrogen)

The concentration of the stock solution you require exceeds the measured solubility. The following solution is for reference only. If necessary, please contact MedChemExpress (MCE).

Method for preparing in vivo working solution for animal experiments: Take μL DMSO stock solution, add μL . μL , mix evenly, next add μL Tween 80, mix evenly, then add μL Saline.

If the continuous dosing period exceeds half a month, please choose this protocol carefully.

Please ensure that the stock solution in the first step is dissolved to a clear state, and add co-solvents in sequence. You can use ultrasonic heating (ultrasonic cleaner, recommended frequency 20-40 kHz), vortexing, etc. to assist dissolution.

Purity & Documentation

Purity: 99.82% ee.: 100.00%

Select Batch:

Data Sheet (287 KB) SDS (393 KB)

COA (267 KB) RP-HPLC (220 KB) NP-HPLC (220 KB) MS (68 KB)

Handling Instructions (2659 KB)

References

[1]. Omoto S, et al. Characterization of influenza virus variants induced by treatment with the endonuclease inhibitor baloxavir marboxil. Sci Rep. 2018 Jun 25;8(1):9633. [Content Brief]

[2]. Noshi T, et al. In vitro characterization of baloxavir acid, a first-in-class cap-dependent endonuclease inhibitor of the influenza virus polymerase PA subunit. Antiviral Res. 2018 Dec;160:109-117. [Content Brief]

Complete Stock Solution Preparation Table

Optional Solvent	Concentration Solvent Mass	1 mg	5 mg	10 mg	25 mg

DMSO	1 mM	2.0683 mL	10.3415 mL	20.6830 mL	51.7074 mL
	5 mM	0.4137 mL	2.0683 mL	4.1366 mL	10.3415 mL
	10 mM	0.2068 mL	1.0341 mL	2.0683 mL	5.1707 mL
	15 mM	0.1379 mL	0.6894 mL	1.3789 mL	3.4472 mL
	20 mM	0.1034 mL	0.5171 mL	1.0341 mL	2.5854 mL
	25 mM	0.0827 mL	0.4137 mL	0.8273 mL	2.0683 mL
	30 mM	0.0689 mL	0.3447 mL	0.6894 mL	1.7236 mL
	40 mM	0.0517 mL	0.2585 mL	0.5171 mL	1.2927 mL
	50 mM	0.0414 mL	0.2068 mL	0.4137 mL	1.0341 mL
	60 mM	0.0345 mL	0.1724 mL	0.3447 mL	0.8618 mL
	80 mM	0.0259 mL	0.1293 mL	0.2585 mL	0.6463 mL

Baloxavir Related Classifications

Help & FAQs

Do most proteins show cross-species activity?
Species cross-reactivity must be investigated individually for each product. Many human cytokines will produce a nice response in mouse cell lines, and many mouse proteins will show activity on human cells. Other proteins may have a lower specific activity when used in the opposite species.

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Baloxavir (Synonyms: Baloxavir acid; S-033447)

Customer Review

Other Forms of Baloxavir:

Baloxavir Related Antibodies

46 Publications Citing Use of MCE Baloxavir

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Purity & Documentation

References

Customer Review

Baloxavir Related Antibodies

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Complete Stock Solution Preparation Table

Baloxavir Related Classifications

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