RK-33

Name: RK-33
Brand: MedChemExpress
SKU: HY-100455
Rating: 5.0 (5 reviews)

Cat. No.: HY-100455 Purity: 99.63%: Data Sheet
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RK-33 is an RNA helicase inhibitor against DDX3, and inhibits its helicase activity.

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

CAS No. : 1070773-09-9

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Solid + Solvent (Highly Recommended)
10 mM * 1 mL in DMSO ready for reconstitution	In-stock	Estimated Time of Arrival: December 31
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10 mM * 1 mL in DMSO	In-stock	Estimated Time of Arrival: December 31
Solid
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10 mg	In-stock	Estimated Time of Arrival: December 31
25 mg	In-stock	Estimated Time of Arrival: December 31
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Customer Review

Based on 5 publication(s) in Google Scholar

Other Forms of RK-33:

RK-33 (Standard) Get quote

5 Publications Citing Use of MCE RK-33

Flow Cytometry

ELISA

: RK-33 purchased from MedChemExpress. Usage Cited in: Free Radic Biol Med. 2025 May:232:330-339. [Abstract]; RK-33 (5 μM; 24 h), a DDX3-specific inhibitor, reinforced increased lipid peroxidation levels in BT549 cells in the presence of hydrogen peroxide.

: RK-33 purchased from MedChemExpress. Usage Cited in: Free Radic Biol Med. 2025 May:232:330-339. [Abstract]; RK-33 (5 μM; 24 h) elevated the levels of lipid peroxidation in MCF7/DDX3X-HA cells when they were exposed to hydrogen peroxide.

: RK-33 purchased from MedChemExpress. Usage Cited in: Free Radic Biol Med. 2025 May:232:330-339. [Abstract]; RK-33 (5-10 μM; 24 h) dose-dependently suppressed GPX4 protein levels in BT549 and MCF7 cells.

: RK-33 purchased from MedChemExpress. Usage Cited in: Int Immunopharmacol. 2023 Apr:117:109779. [Abstract]; RK-33 (20 mg/kg; i.p.; once daily) down-regulated the levels of CRP, IL-6 and TNF-α in the peripheral blood of CLP-induced septic mice.

: RK-33 purchased from MedChemExpress. Usage Cited in: Int Immunopharmacol. 2023 Apr:117:109779. [Abstract]; RK-33 (20 mg/kg; i.p.; once daily) improved the total number of CD4⁺ and CD8⁺ T cells in septic mice reduced by CLP.

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Biological Activity
Protocol
Purity & Documentation
References
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Description

RK-33 is an RNA helicase inhibitor against DDX3, and inhibits its helicase activity.

IC₅₀ & Target

Helicase

Cellular Effect

Cell Line	Type	Value	Description	References
A549	IC₅₀	2.5 μM Compound: 1	Cytotoxicity against human A549 cells after 72 hrs by WST1 assay Cytotoxicity against human A549 cells after 72 hrs by WST1 assay	[PMID: 21572541]
A549	IC₅₀	2.56 μM Compound: 1	Cytotoxicity against human A549 cells after 72 hrs by WST1 assay Cytotoxicity against human A549 cells after 72 hrs by WST1 assay	[PMID: 23290252]
Daoy	IC₅₀	2.5 μM Compound: RK-33	Antiproliferative activity against human Daoy cells assessed as inhibition of cell proliferation incubated for 72 hrs by MTS assay Antiproliferative activity against human Daoy cells assessed as inhibition of cell proliferation incubated for 72 hrs by MTS assay	[PMID: 33636537]
Huh-7	CC₅₀	< 10 μM Compound: 51	Cytotoxicity against human Huh-7 cells assessed as reduction in cell viability Cytotoxicity against human Huh-7 cells assessed as reduction in cell viability	[PMID: 35899912]
MCF7	IC₅₀	7.5 μM Compound: 1	Cytotoxicity against human MCF7 cells after 72 hrs by WST1 assay Cytotoxicity against human MCF7 cells after 72 hrs by WST1 assay	[PMID: 21572541]
MCF7	IC₅₀	7.59 μM Compound: 1	Cytotoxicity against human MCF7 cells after 72 hrs by WST1 assay Cytotoxicity against human MCF7 cells after 72 hrs by WST1 assay	[PMID: 23290252]
MDA-MB-231	IC₅₀	4.01 μM Compound: 1	Cytotoxicity against human MDA-MB-231 cells after 72 hrs by WST1 assay Cytotoxicity against human MDA-MB-231 cells after 72 hrs by WST1 assay	[PMID: 21572541]
MDA-MB-231	IC₅₀	4.05 μM Compound: 1	Cytotoxicity against human MDA-MB-231 cells after 72 hrs by WST1 assay Cytotoxicity against human MDA-MB-231 cells after 72 hrs by WST1 assay	[PMID: 23290252]
NCI-H460	IC₅₀	2.8 μM Compound: 1	Cytotoxicity against human H460 cells after 72 hrs by WST1 assay Cytotoxicity against human H460 cells after 72 hrs by WST1 assay	[PMID: 21572541]
NCI-H460	IC₅₀	2.87 μM Compound: 1	Cytotoxicity against human H460 cells after 72 hrs by WST1 assay Cytotoxicity against human H460 cells after 72 hrs by WST1 assay	[PMID: 23290252]
OVCAR-3	IC₅₀	14.5 μM Compound: 1	Cytotoxicity against human OVCAR3 cells after 72 hrs by WST1 assay Cytotoxicity against human OVCAR3 cells after 72 hrs by WST1 assay	[PMID: 21572541]
OVCAR-3	IC₅₀	14.5 μM Compound: 1	Cytotoxicity against human OVCAR3 cells after 72 hrs by WST1 assay Cytotoxicity against human OVCAR3 cells after 72 hrs by WST1 assay	[PMID: 23290252]
PC-3	IC₅₀	4.8 μM Compound: 1	Cytotoxicity against human PC3 cells after 72 hrs by WST1 assay Cytotoxicity against human PC3 cells after 72 hrs by WST1 assay	[PMID: 21572541]
PC-3	IC₅₀	4.9 μM Compound: 1	Cytotoxicity against human PC3 cells after 72 hrs by WST1 assay Cytotoxicity against human PC3 cells after 72 hrs by WST1 assay	[PMID: 23290252]
Vero	CC₅₀	29.7 μM Compound: 51	Cytotoxicity against African green monkey Vero cells assessed as reduction in cell viability incubated for 22 hrs by XTT assay Cytotoxicity against African green monkey Vero cells assessed as reduction in cell viability incubated for 22 hrs by XTT assay	[PMID: 35899912]
Vero C1008	CC₅₀	> 30 μM Compound: 51	Cytotoxicity against African green monkey Vero E6 cells assessed as reduction in cell viability Cytotoxicity against African green monkey Vero E6 cells assessed as reduction in cell viability	[PMID: 35899912]

In Vitro

RK-33 shows inhibition of many kinds of cancer cells with IC₅₀ of 3-6 μM, while PC3 is much less sensitive to RK-33 (IC₅₀ >12 μM). RK-33 treatment causes a significant accumulation in the G1 phase for DU145 and LNCaP, although treatment with RK-33 causes only a moderate accumulation of the G1 phase for 22Rv1, and the treated cells have significantly reduced G2 phase. RK-33 treatment also causes 12 moderate G1 accumulation in 22Rv1^[1]. RK-33-loaded NPs demonstrate cytotoxicity to MCF-7 cells in a dose-dependent manner, while equivalent doses of empty NPs have no killing effect. The IC₅₀ value of 5% RK-33 loaded NPs is 49 μg/mL, and the IC₅₀ value of 10% RK-33 loaded NPs is 25 μg/mL^[2].

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

In Vivo

There is more cell death (pyknotic or condensed nuclei) admixed with fibrin and interstitial edema in the tumors from mice from the combination RK-33 and radiation group compared to the control or single treatment groups. The treatment combination of RK-33 and radiation has an advantage in reducing tumor proliferation^[1]. In the mice treated with RK-33-PLGA, RK-33 can be detected in the plasma (34 μg/mL) and liver (28 μg/g), but not lungs^[2].

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

Molecular Weight

428.44

Formula

C₂₃H₂₀N₆O₃

CAS No.

1070773-09-9

Appearance

Solid

Color

Light yellow to yellow

SMILES

O=C1N(CC2=CC=C(OC)C=C2)C3=NC=NC4=C(N=CN4CC5=CC=C(OC)C=C5)C3=N1

Shipping

Room temperature in continental US; may vary elsewhere.

Storage

Powder	-20°C	3 years
	4°C	2 years
In solvent	-80°C	2 years
	-20°C	1 year

Solvent & Solubility

In Vitro:

DMSO : 25 mg/mL (58.35 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	2.3340 mL	11.6702 mL	23.3405 mL
5 mM	0.4668 mL	2.3340 mL	4.6681 mL
10 mM	0.2334 mL	1.1670 mL	2.3340 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, 2 years; -20°C, 1 year. When stored at -80°C, please use it within 2 years. When stored at -20°C, please use it within 1 year.

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:

For the following dissolution methods, please prepare the working solution directly. It is recommended to prepare fresh solutions and use them promptly within a short period of time.
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: 50% PEG300 50% Saline
Solubility: 2 mg/mL (4.67 mM); Suspended solution; Need ultrasonic

In Vivo Dissolution Calculator

Please enter the basic information of animal experiments:

Dosage

mg/kg

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(per animal)

μL

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

Calculation results:

Working solution concentration: mg/mL

Purity & Documentation

Purity: 99.63%

Select Batch:

Data Sheet (280 KB) SDS (393 KB)

COA (252 KB) HNMR (395 KB) RP-HPLC (254 KB) LCMS (97 KB)

Handling Instructions (2659 KB)

References

[1]. Xie M,et al. RK-33 radiosensitizes prostate cancer cells by blocking the RNA helicase DDX3. Cancer Res. 2016 Sep 12. [Content Brief]

[2]. Bol GM, e tal. PLGA nanoparticle formulation of RK-33: an RNA helicase inhibitor against DDX3. Cancer Chemother Pharmacol. 2015 Oct;76(4):821-7. [Content Brief]

Cell Assay ^[2]	Briefly, 8×10² MCF-7 cells are seeded in a 96-well plate, and treated with different concentrations of RK-33 loaded nanoparticles and unloaded nanoparticles next day. After 72-h incubation, MTS reagent is added to the cells, and the absorbance is measured at 490 nm after 2-h incubation with MTS reagent. The experiment is repeated three independent times. MCE has not independently confirmed the accuracy of these methods. They are for reference only.
Animal Administration ^[1]	Mice are randomLy redistributed into four groups of eight according to their tumor growth, which results in an approximately equal distribution of tumor size at the beginning of radiation and RK-33 drug treatment. The four groups of mice are blindly chosen for four different experimental procedures, including control (injection of DMSO only), RK-33 treatment (injection of RK-33 only 50 mg/kg), radiation (one-time radiation of 5 Gy), or radiation and RK-33 treatment (combination of radiation of 5 Gy and RK-33 injection). RK-33 and DMSO are injected intraperitoneally thrice weekly for two weeks. Radiation is performed at the beginning of drug injection using the Small Animal Radiation Research Platform (SARRP) with a circular beam of 1 cm diameter, focusing on the tumor site. Mice of each group are euthanized 0 h and 24 h after radiation and tumors are extracted for γH2AX, cleaved Caspase 3, and Ki67 staining. The remaining mice of each group are imaged with a Xenogen IVIS Spectrum, with injection of D-luciferin 5 minutes before imaging. Mice are euthanized after six weeks of imaging and tumors are extracted for H&E staining, cleaved Caspase 3, and i67 staining. Morphology of the tumors after RK-33 and radiation treatment is assessed by a veterinary pathologist on hematoxylin and eosin stained sections. MCE has not independently confirmed the accuracy of these methods. They are for reference only.
References	[1]. Xie M,et al. RK-33 radiosensitizes prostate cancer cells by blocking the RNA helicase DDX3. Cancer Res. 2016 Sep 12. [Content Brief] [2]. Bol GM, e tal. PLGA nanoparticle formulation of RK-33: an RNA helicase inhibitor against DDX3. Cancer Chemother Pharmacol. 2015 Oct;76(4):821-7. [Content Brief]

Complete Stock Solution Preparation Table

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

DMSO	1 mM	2.3340 mL	11.6702 mL	23.3405 mL	58.3512 mL
	5 mM	0.4668 mL	2.3340 mL	4.6681 mL	11.6702 mL
	10 mM	0.2334 mL	1.1670 mL	2.3340 mL	5.8351 mL
	15 mM	0.1556 mL	0.7780 mL	1.5560 mL	3.8901 mL
	20 mM	0.1167 mL	0.5835 mL	1.1670 mL	2.9176 mL
	25 mM	0.0934 mL	0.4668 mL	0.9336 mL	2.3340 mL
	30 mM	0.0778 mL	0.3890 mL	0.7780 mL	1.9450 mL
	40 mM	0.0584 mL	0.2918 mL	0.5835 mL	1.4588 mL
	50 mM	0.0467 mL	0.2334 mL	0.4668 mL	1.1670 mL

RK-33 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.

Keywords:

RK-331070773-09-9RK33RK 33DNA/RNA SynthesisSARS-CoVSARS coronavirusInhibitorinhibitorinhibit

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RK-33

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Other Forms of RK-33:

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5 Publications Citing Use of MCE RK-33

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•Related Screening Libraries:

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References

Customer Review

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Complete Stock Solution Preparation Table

RK-33 Related Classifications

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