Cat. No.: HY-143216

Ensitrelvir

(Synonyms: S-217622)

16 Cited Publications

Customer Review

Based on 16 publication(s) in Google Scholar

Ensitrelvir (S-217622) is the first orally active non-covalent, non-peptidic, SARS-CoV-2 3CL protease inhibitor (IC₅₀=13 nM).

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

Purity: 99.61%
CAS No.: 2647530-73-0
Formula: C₂₂H₁₇ClF₃N₉O₂
Molecular Weight:531.88

Storage:

Powder -20°C, 3 years , 4°C, 2 years ; In solvent -80°C, 6 months , -20°C, 1 month

Ensitrelvir Chemical Structure

CAS No.: 2647530-73-0

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Top Publications Citing

Use of MCE Products

Fluorescent Dye

Strong Fluorescence Signal / Multi-Disciplinary Applications / High Fluorescence Specificity

Biological Activity
- Description
- Cellular Effect
- In Vitro
- In Vivo
Chemical Information
Publications (16)
Solvent & Solubility
- In Vitro
- In Vivo
Purity & Documentation
References
Help & FAQs
Bioz

Biological Activity

Description

Ensitrelvir (S-217622) is the first orally active non-covalent, non-peptidic, SARS-CoV-2 3CL protease inhibitor (IC₅₀=13 nM)^[1]^[2].

Cellular Effect

Cell Line	Type	Value	Description	References
Vero C1008	CC₅₀	>100 μM Compound: S-216722	Cytotoxicity against African green monkey Vero E6 cells assessed as reduction in cell viability incubated for 26 hrs by celltiter 96 aqueous non-radioactive cell proliferation assay Cytotoxicity against African green monkey Vero E6 cells assessed as reduction in cell viability incubated for 26 hrs by celltiter 96 aqueous non-radioactive cell proliferation assay	[PMID: 36107752]
Vero C1008	EC₅₀	0.35 μM Compound: S-217622	Antiviral activity against SARS-CoV-2 infected in African green monkey Vero E6 cells expressing TMPRSS2 assessed as reduction in virus-induced cytopathic effect measured after 48 hrs by cellular ATP assay Antiviral activity against SARS-CoV-2 infected in African green monkey Vero E6 cells expressing TMPRSS2 assessed as reduction in virus-induced cytopathic effect measured after 48 hrs by cellular ATP assay	[PMID: 37229831]

In Vitro

In a cytopathic effect (cpe)-inhibition assay of SARS-CoV-2 infected VeroE6/TMPRSS2 cells, Ensitrelvir shows the EC₅₀ values are approximately 0.4 μM for both wild-type virus and Alpha, Beta, Gamma and Delta variants. EC₅₀ values for SARS-CoV and MERS-CoV were 0.21 and 1.4 μM respectively^[1].

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

In Vivo

Ensitrelvir dose-dependently inhibits intrapulmonary replication of SARS-CoV-2 in mice^[2].

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

Chemical Information

CAS No. 2647530-73-0
Appearance Solid
Molecular Weight 531.88
Formula C₂₂H₁₇ClF₃N₉O₂
Color White to light yellow
SMILES

FC1=C(CN2C(N(CC3=NN(C)C=N3)C(N/C2=N\C4=CC5=CN(C)N=C5C=C4Cl)=O)=O)C=C(F)C(F)=C1
Synonyms

S-217622
Shipping

Room temperature in continental US; may vary elsewhere.

Storage

Powder	-20°C	3 years
	4°C	2 years
In solvent	-80°C	6 months
	-20°C	1 month

Publications (16)

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Journal Impact Factor

Nat Commun

Identification of SARS-CoV-2 Mpro inhibitors containing P1' 4-fluorobenzothiazole moiety highly active against SARS-CoV-2. [Abstract]

2023 Feb 25;14(1):1076. PMID: 36841831
Emerg Microbes Infect

SARS-CoV-2 Mpro inhibitor ensitrelvir: asymmetrical cross-resistance with nirmatrelvir and emerging resistance hotspots. [Abstract]

2025 Dec;14(1):2552716. PMID: 41088534
Anal Chem

Decoding Enzyme-Inhibitor Kinetic Mechanisms by Isothermal Titration Calorimetry: The Case of SARS-CoV-2 3CLpro. [Abstract]

2026 Jun 23. PMID: 42334227
ACS Omega

Impact of Single Halogen Atom Substitutions on Antiviral Profile of Inhibitors Targeting SARS-CoV‑2 Main Protease. [Abstract]

2026 Jan 14;11(3):4541-4550. PMID: 41626465
Structure

Structural basis for the inhibition of coronaviral main proteases by ensitrelvir. [Abstract]

2023 Sep 7;31(9):1016-1024.e3. PMID: 37421945
J Biol Chem

Contribution of the catalytic dyad of SARS-CoV-2 main protease to binding covalent and noncovalent inhibitors. [Abstract]

2023 Jul;299(7):104886. PMID: 37271339
PNAS Nexus

An orally available P1'-5-fluorinated Mpro inhibitor blocks SARS-CoV-2 replication without booster and exhibits high genetic barrier. [Abstract]

2025 Jan 7;4(1):pgae578. PMID: 39831159
ACS Pharmacol Transl Sci

2026 Jan 28.
ACS Pharmacol Transl Sci

Development of a Cell-Based Recombinant Green Fluorescent Protein Assay System for Generalized Discovery of Viral Protease Inhibitors. [Abstract]

2025 Oct 9;8(11):3944-3952. PMID: 41262580
Res Sq

2025 Jul 29.
bioRxiv

A non-spike nucleocapsid R204P mutation in SARS-CoV-2 Omicron XEC enhances inflammation and pathogenicity. [Abstract]

2025 May 30:2025.05.28.656516. PMID: 40502047
Res Sq

2025 Apr 20.
bioRxiv

2024 Feb 3.
bioRxiv

2023 Nov 27.
bioRxiv

2023 Oct 21.
bioRxiv

Rapid resistance profiling of SARS-CoV-2 protease inhibitors. [Abstract]

2023 Feb 27:2023.02.25.530000. PMID: 36909573

Solvent & Solubility

In Vitro:

DMSO : 50 mg/mL (94.01 mM; Need ultrasonic; Hygroscopic DMSO has a significant impact on the solubility of product, please use newly opened DMSO)

View the Complete Stock Solution Preparation Table

Preparing Stock Solutions

View the Complete Stock Solution Preparation Table

Concentration Solvent Mass

1 mg

5 mg

10 mg

Concentration

Solvent

Mass

1 mM

1.8801 mL

9.4006 mL

18.8012 mL

5 mM

0.3760 mL

1.8801 mL

3.7602 mL

10 mM

0.1880 mL

0.9401 mL

1.8801 mL

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, 6 months; -20°C, 1 month. When stored at -80°C, please use it within 6 months. When stored at -20°C, please use it within 1 month.

Molarity Calculator

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

Mass Mass

Concentration Concentration

Volume Volume

Molecular Weight Molecular Weight

Dilution Calculator

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

Concentration _(start) Concentration _(start)

Volume _(start) Volume _(start)

Concentration _(final) Concentration _(final)

Volume _(final) Volume _(final)

In Vivo:

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

Stock Solution Working Solution

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: ≥ 2.5 mg/mL (4.70 mM); Clear solution

This protocol yields a clear solution of ≥ 2.5 mg/mL (saturation unknown).

Taking 1 mL working solution as an example, add 100 μL DMSO stock solution (25.0 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.

Protocol 2

Add each solvent one by one: 10% DMSO 90% (20% SBE-β-CD in Saline)

Solubility: ≥ 2.5 mg/mL (4.70 mM); Clear solution

This protocol yields a clear solution of ≥ 2.5 mg/mL (saturation unknown).

Taking 1 mL working solution as an example, add 100 μL DMSO stock solution (25.0 mg/mL) to 900 μL 20% SBE-β-CD in Saline, and mix evenly.

Protocol 3

Add each solvent one by one: 10% DMSO 90% Corn Oil

Solubility: ≥ 2.5 mg/mL (4.70 mM); Clear solution

This protocol yields a clear solution of ≥ 2.5 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 (25.0 mg/mL) to 900 μL Corn oil, and mix evenly.

In Vivo Dissolution Calculator

Please enter the basic information of animal experiments:

Dosage Dosage
mg/kg
Animal Weight (Per Animal) Animal Weight (Per Animal)
g
Dosing Volume (Per Animal) Dosing Volume (Per Animal)
μL
Number of Animals Number of Animals

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

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

Please enter your animal formula composition:

%
DMSO +

Recommended: Keep the proportion of DMSO in working solution below 2% if your animal is weak.
%
+
+
%
Tween-80 + +
%
Saline +

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).

Working solution concentration: 0.22 mg/mL

Purity & Documentation

Select Batch:

Purity: 99.98%

Assay: 99.98%

ee.: 99.98%

Data Sheet (280 KB)
SDS (393 KB)
- English - EN (393 KB)
- Français - FR (393 KB)
- Deutsch - DE (393 KB)
- Norwegian - NO (393 KB)
- Español - ES (393 KB)
- Swedish - SV (393 KB)
- Italian - IT (393 KB)
- Portuguese - PT (393 KB)
COA (2659 KB)
Elemental Analysis Report (2659 KB)
HNMR (2659 KB)
CNMR (2659 KB)
RP-HPLC (2659 KB)
NP-HPLC (2659 KB)
MS (2659 KB)
LCMS (2659 KB)
IR (2659 KB)
GC (2659 KB)
OR (2659 KB)
SDS-PAGE (2659 KB)
SEC-HPLC (2659 KB)
Other Report (2659 KB)
Handling Instructions (2659 KB)

References

[1]. McKimm-Breschkin JL, et al. COVID-19, Influenza and RSV: Surveillance-informed prevention and treatment - Meeting report from an isirv-WHO virtual conference. Antiviral Res. 2022;197:105227. [Content Brief]

[2]. Yuto Unoh, et al. Discovery of S-217622, a Non-Covalent Oral SARS-CoV-2 3CL Protease Inhibitor Clinical Candidate for Treating COVID-19. bioRxiv 2022.01.26.477782.

Help & FAQs

How should lyophilized recombinant proteins be reconstituted and stored?

1. Before opening the cap, centrifuge the vial at 13000 rpm for 20-30 seconds. This step will ensure that any lyophilized powder that may have adhered to the cap or walls is collected at the bottom of the vial, minimizing the risk of product loss.

Complete Stock Solution Preparation Table

Storage method and period of stock solution: -80°C, 6 months; -20°C, 1 month. When stored at -80°C, please use it within 6 months. When stored at -20°C, please use it within 1 month.

Optional Solvent	Concentration Solvent Mass	1 mg	5 mg	10 mg	25 mg
DMSO	1 mM	1.8801 mL	9.4006 mL	18.8012 mL	47.0031 mL
	5 mM	0.3760 mL	1.8801 mL	3.7602 mL	9.4006 mL
	10 mM	0.1880 mL	0.9401 mL	1.8801 mL	4.7003 mL
	15 mM	0.1253 mL	0.6267 mL	1.2534 mL	3.1335 mL
	20 mM	0.0940 mL	0.4700 mL	0.9401 mL	2.3502 mL
	25 mM	0.0752 mL	0.3760 mL	0.7520 mL	1.8801 mL
	30 mM	0.0627 mL	0.3134 mL	0.6267 mL	1.5668 mL
	40 mM	0.0470 mL	0.2350 mL	0.4700 mL	1.1751 mL
	50 mM	0.0376 mL	0.1880 mL	0.3760 mL	0.9401 mL
	60 mM	0.0313 mL	0.1567 mL	0.3134 mL	0.7834 mL
	80 mM	0.0235 mL	0.1175 mL	0.2350 mL	0.5875 mL

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Ensitrelvir

Anti-Infection Compound Library

Antiviral Compound Library

Orally Active Compound Library

Heterocyclic Compound Library

Protease Inhibitor Library

Multi-Target Compound Library

Bioactive Compound Library Max

MCE Bioactive Compound Library

Bioactive Compound Library

High-Throughput Bioactive Compound Library

Publications Citing Use of MedChemExpress (MCE) Ensitrelvir

Biological Activity

Chemical Information

Publications (16)

Solvent & Solubility

Purity & Documentation

References

Help & FAQs

Complete Stock Solution Preparation Table

Ensitrelvir

Anti-Infection Compound Library

Antiviral Compound Library

Orally Active Compound Library

Heterocyclic Compound Library

Protease Inhibitor Library

Multi-Target Compound Library

Bioactive Compound Library Max

MCE Bioactive Compound Library

Bioactive Compound Library

High-Throughput Bioactive Compound Library

Publications Citing Use of MedChemExpress (MCE) Ensitrelvir

Biological Activity

Chemical Information

Publications (16)

Solvent & Solubility

Purity & Documentation

References

Help & FAQs

Complete Stock Solution Preparation Table

Ensitrelvir Related Classifications

Cat. No.: HY-143216