Leptomycin B (Synonyms: CI 940; LMB)

Name: Leptomycin B
Brand: MedChemExpress
SKU: HY-16909
Rating: 5.0 (21 reviews)

Cat. No.: HY-16909 Purity: 99.79%: Data Sheet
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Leptomycin B (CI 940; LMB) is a potent inhibitor of the nuclear export of proteins. Leptomycin B inactivates CRM1/exportin 1 by covalent modification at a cysteine residue. Leptomycin B is a potent antifungal antibiotic blocking the eukaryotic cell cycle.

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

CAS No. : 87081-35-4

Size	Stock	Quantity
Solid or liquid + 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 or liquid
1 mg	In-stock	Estimated Time of Arrival: December 31
5 mg	In-stock	Estimated Time of Arrival: December 31
10 mg	In-stock	Estimated Time of Arrival: December 31
50 mg	Get quote
100 mg	Get quote

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Based on 21 publication(s) in Google Scholar

21 Publications Citing Use of MCE Leptomycin B

Cell Imaging/Staining

: Leptomycin B purchased from MedChemExpress. Usage Cited in: J Adv Res. 2025 Jun 2:S2090-1232(25)00374-1. [Abstract]; Nuclear and cytoplasmic RAN, pSTAT1/2, and STAT1/2RD in RD cells treated with or without voxtalisib (37 °C, 22 h), leptomycin B (10 ng/mL; 4 h), and IFN-α (10 ng/mL).

: Leptomycin B purchased from MedChemExpress. Usage Cited in: Emerg Microbes Infect. 2024 Aug 1:2387910. [Abstract]; Cells were fixed and permeabilized at 2 h or 6 h post-infection and then immunostained for NP. Baf-A1 (100 nM) and Leptomycin (10 ng/mL) were used as nuclear import and export inhibition controls, respectively.

: Leptomycin B purchased from MedChemExpress. Usage Cited in: Emerg Microbes Infect. 2024 Aug 1:2387910. [Abstract]; A549 cells treated with bepotastine (30 μM) and Leptomycin (10 ng/mL) were infected with the indicated viruses at an MOI of 10.

: Leptomycin B purchased from MedChemExpress. Usage Cited in: Cell Death Discov. 2024 Oct 26;10(1):453. [Abstract]; T24 cells were treated with 1µM PD with or without 0.5nM Leptomycin B for 8 h. The subcellular localization of RB and pRB was analyzed using Western blotting.

: Leptomycin B purchased from MedChemExpress. Usage Cited in: Cell Death Discov. 2024 Oct 26;10(1):453. [Abstract]; T24 cells were treated with PD, IPZ, Leptomycin B (0.5 nM) mono- or combination therapy for 8h. Immunofluorescence staining was used to determine subcellular localization of RB and pRB. The scale bar equaled 20µm.

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Biological Activity
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References
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Description

IC₅₀ & Target

CRM1/exportin 1^[1]

Cellular Effect

Cell Line	Type	Value	Description	References
HCT-116	IC₅₀	0.3 nM Compound: LMB	Antiproliferative activity against human HCT-116 cells assessed as inhibition of cell growth incubated for 1 hrs by CellTiter Glo assay Antiproliferative activity against human HCT-116 cells assessed as inhibition of cell growth incubated for 1 hrs by CellTiter Glo assay	[PMID: 38105606]
HCT-116	IC₅₀	0.3 nM Compound: LMB	Antiproliferative activity against human HCT-116 cells assessed as inhibition of cell growth incubated for 72 hrs by CellTiter Glo assay Antiproliferative activity against human HCT-116 cells assessed as inhibition of cell growth incubated for 72 hrs by CellTiter Glo assay	[PMID: 38105606]
HeLa	EC₅₀	0.00822 μM Compound: Leptomycin B	Inhibition of HIV1 Rev expressed in human HeLa cells co-expressing renilla luciferase reporter gene assessed as inhibition of renilla luciferase expression after 24 hrs Inhibition of HIV1 Rev expressed in human HeLa cells co-expressing renilla luciferase reporter gene assessed as inhibition of renilla luciferase expression after 24 hrs	[PMID: 18625767]
HeLa	IC₅₀	1 nM Compound: 128; LMB	Inhibition of CRM1-mediated nucleocytoplasmic transport in human HeLa cells after 90 mins by immunofluorescence assay Inhibition of CRM1-mediated nucleocytoplasmic transport in human HeLa cells after 90 mins by immunofluorescence assay	[PMID: 27996267]
MDCK	CC₅₀	> 0.88 μM Compound: LMB	Cytotoxicity against MDCK cells assessed as cell death after 72 hrs by MTT assay Cytotoxicity against MDCK cells assessed as cell death after 72 hrs by MTT assay	[PMID: 30753063]
SK-N-SH	IC₅₀	0.3 nM Compound: LMB	Antiproliferative activity against human SK-N-SH cells assessed as inhibition of cell growth incubated for 1 hrs by CellTiter Glo assay Antiproliferative activity against human SK-N-SH cells assessed as inhibition of cell growth incubated for 1 hrs by CellTiter Glo assay	[PMID: 38105606]
SK-N-SH	IC₅₀	0.3 nM Compound: LMB	Antiproliferative activity against human SK-N-SH cells assessed as inhibition of cell growth incubated for 72 hrs by CellTiter Glo assay Antiproliferative activity against human SK-N-SH cells assessed as inhibition of cell growth incubated for 72 hrs by CellTiter Glo assay	[PMID: 38105606]
SiHa	IC₅₀	0.3 nM Compound: LMB	Antiproliferative activity against human SiHa cells assessed as inhibition of cell growth incubated for 1 hrs by CellTiter Glo assay Antiproliferative activity against human SiHa cells assessed as inhibition of cell growth incubated for 1 hrs by CellTiter Glo assay	[PMID: 38105606]
SiHa	IC₅₀	0.3 nM Compound: LMB	Antiproliferative activity against human SiHa cells assessed as inhibition of cell growth incubated for 72 hrs by CellTiter Glo assay Antiproliferative activity against human SiHa cells assessed as inhibition of cell growth incubated for 72 hrs by CellTiter Glo assay	[PMID: 38105606]

In Vitro

Leptomycin B (LMB) is very potent in vitro against various cancer cell lines (IC50 values in the 0.1 to 10 nM range). Leptomycin B (LMB) inhibits SiHa, HCT-116, and SKNSH cells with IC₅₀s of 0.4, 0.3 and 0.4 nM for a 72 hour exposure, respectively^[2].
Leptomycin B (LMB) (0.5 nM) displays a synergistic effect on Gefitinib (0–32 μM)-induced cytotoxicity in A549 and H460 cell line. The simultaneous treatments of Gefitinib (0–32 μM) and Leptomycin B (0.5 nM) show synergistic cytotoxic effect on A549 as compared to Gefitinib alone at both 24 and 48 hours^[3].

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

Cell Viability Assay^[3]

Cell Line:	The non-small cell lung cancer (NSCLC) cell lines A549 and H460
Concentration:	0.5 nM
Incubation Time:	24 and 48 hours
Result:	The IC₅₀ of Gefitinib at 48 hours was 32.0±2.5 μM while it was significantly reduced to 25.0±2.1 μM with the combination of 0.5 nM Leptomycin B. The significant synergistic cytotoxic effect from co-treatment of 0.5 nM Leptomycin B with Gefitinib was also confirmed in H460 cell line.

Cell Viability Assay^[3]

Cell Line:	A549
Concentration:	0.5 nM
Incubation Time:	48 hours
Result:	0.5 nM Leptomycin B plus Gefitinib or Gefitinib alone had a decreased p-EGFR(Tyr1068) expressions compared with controls. p-Akt (Ser473) was inhibited in a dose-response manner by Gefitinib treatments, but it was enhanced by gefitinib+Leptomycin B co-treatments compared with gefitinib alone. A549 treated by Gefitinib+Leptomycin B had a higher expression of p-Erk1/2(Thr202/Tyr204) than A549 treated by Gefitinib alone.

In Vivo

Leptomycin B (LMB) is poorly tolerated in vivo. Maximum tolerated dose (MTD) is 2.5 mg/kg for LMB (single i.v.) in HCT-116 tumor–bearing mice.The limited in vivo efficacy of Leptomycin B is due to off-target effects because our nuclear export inhibitors (NEIs) retain the potent inhibition of CRM1, but are clearly better tolerated in vivo^[4].

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

Clinical Trial

Molecular Weight

540.73

Formula

C₃₃H₄₈O₆

CAS No.

87081-35-4

Appearance

<41°C Solid,>44°C Liquid

Color

White to yellow

SMILES

O=C(O)/C=C(C)/C[C@H](C)[C@@H](O)[C@H](C)C([C@H](C)/C=C(C)/C=C/C[C@@H](C)/C=C(CC)\C=C\[C@H]1[C@@H](C)C=CC(O1)=O)=O

Shipping

Room temperature in continental US; may vary elsewhere.

Storage

-20°C, stored under nitrogen

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

Solvent & Solubility

In Vitro:

DMSO : 100 mg/mL (184.94 mM; Need ultrasonic; 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	1.8494 mL	9.2468 mL	18.4935 mL
5 mM	0.3699 mL	1.8494 mL	3.6987 mL
10 mM	0.1849 mL	0.9247 mL	1.8494 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, 6 months; -20°C, 1 month (stored under nitrogen). When stored at -80°C, please use it within 6 months. When stored at -20°C, please use it within 1 month.

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: ≥ 2.5 mg/mL (4.62 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.
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% (20% SBE-β-CD in Saline)
Solubility: 2.5 mg/mL (4.62 mM); Suspended solution; Need ultrasonic

This protocol yields a suspended solution of 2.5 mg/mL. Suspended solution can be used for oral and intraperitoneal injection.
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.
Preparation of 20% SBE-β-CD in Saline (4°C, storage for one week): 2 g SBE-β-CD powder is dissolved in 10 mL Saline, completely dissolve until clear.
Protocol 3

Add each solvent one by one: 10% DMSO 90% Corn Oil
Solubility: 2.5 mg/mL (4.62 mM); Clear solution; Need ultrasonic

This protocol yields a clear solution of 2.5 mg/mL. 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

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, 6 months; -20°C, 1 month (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: 99.79%

Select Batch:

Data Sheet (276 KB) SDS (393 KB)

COA (245 KB) HNMR (458 KB) RP-HPLC (255 KB) LCMS (97 KB)

Handling Instructions (2659 KB)

References

[1]. N Kudo, et al. Leptomycin B inactivates CRM1/exportin 1 by covalent modification at a cysteine residue in the central conserved region. Proc Natl Acad Sci U S A. 1999 Aug 3;96(16):9112-7. [Content Brief]

[2]. Sarah C Mutka,et al. Identification of nuclear export inhibitors with potent anticancer activity in vivo. Cancer Res. 2009 Jan 15;69(2):510-7. [Content Brief]

[3]. Zhongwei Liu, et al.Leptomycin B reduces primary and acquired resistance of gefitinib in lung cancer cells. Toxicol Appl Pharmacol. 2017 Nov 15;335:16-27. [Content Brief]

[4]. Sarah C Mutka, et al. Identification of nuclear export inhibitors with potent anticancer activity in vivo. Cancer Res. 2009 Jan 15;69(2):510-7. [Content Brief]

Complete Stock Solution Preparation Table

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

DMSO	1 mM	1.8494 mL	9.2468 mL	18.4935 mL	46.2338 mL
	5 mM	0.3699 mL	1.8494 mL	3.6987 mL	9.2468 mL
	10 mM	0.1849 mL	0.9247 mL	1.8494 mL	4.6234 mL
	15 mM	0.1233 mL	0.6165 mL	1.2329 mL	3.0823 mL
	20 mM	0.0925 mL	0.4623 mL	0.9247 mL	2.3117 mL
	25 mM	0.0740 mL	0.3699 mL	0.7397 mL	1.8494 mL
	30 mM	0.0616 mL	0.3082 mL	0.6165 mL	1.5411 mL
	40 mM	0.0462 mL	0.2312 mL	0.4623 mL	1.1558 mL
	50 mM	0.0370 mL	0.1849 mL	0.3699 mL	0.9247 mL
	60 mM	0.0308 mL	0.1541 mL	0.3082 mL	0.7706 mL
	80 mM	0.0231 mL	0.1156 mL	0.2312 mL	0.5779 mL
	100 mM	0.0185 mL	0.0925 mL	0.1849 mL	0.4623 mL

Leptomycin B 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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Leptomycin B (Synonyms: CI 940; LMB)

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Leptomycin B Related Antibodies

21 Publications Citing Use of MCE Leptomycin B

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