For research use only.

Catalog No.S7261 Synonyms: β-Lapachone, ARQ-501

4 publications

Beta-Lapachone Chemical Structure

CAS No. 4707-32-8

Beta-Lapachone (β-Lapachone, ARQ-501) is a selective DNA topoisomerase I inhibitor, exhibiting no inhibitory activities against DNA topoisomerase II or ligase. Phase 2.

Size Price Stock Quantity  
USD 147 In stock
USD 470 In stock
Bulk Discount

Free Overnight Delivery on orders over $ 500
Next day delivery by 10:00 a.m. Order now.

Selleck's Beta-Lapachone has been cited by 4 publications

Purity & Quality Control

Choose Selective Topoisomerase Inhibitors

Biological Activity

Description Beta-Lapachone (β-Lapachone, ARQ-501) is a selective DNA topoisomerase I inhibitor, exhibiting no inhibitory activities against DNA topoisomerase II or ligase. Phase 2.
Topo I [1] IDO1 [4]
0.44 μM
In vitro

Beta-Lapachone inhibits DNA relaxation induced by DNA topoisomerase I in a dose-dependent manner. [1] Treatment of beta-lapachone (100 nM or greater) results in >95% inhibition of Topo I DNA unwinding activity compared to the DMSO control. beta-lapachone (1-5 μM) causes a block in G0/G1 of the cell cycle and induces apoptosis by locking Topo I onto DNA and blocking replication fork movement in HL-60 and three human prostate cancer (DU-145, PC-3, and LNCaP) cells. [2] Beta-Lapachone facilitates the migration of mouse 3T3 fibroblasts and human endothelial EAhy926 cells through different MAPK signaling pathways, and thus accelerates scrape-wound healing in vitro. [3] In addition, beta-Lapachone inhibits purified recombinant IDO1 activity through uncompetitive inhibition with IC50 of 0.44 μM, and beta-lapachone also exhibits superior retention of intracellular IDO1 inhibitory activity with an IC50 of 1.0 μM, partially dependent on biotransformation by NQO1. [4] Beta-lapachone induces programmed necrosis of NQO1+ cancer cells by NQO1-dependent reactive oxygen species (ROS) formation and PARP1 hyperactivation. [5]

In vivo Beta-lapachone treatment (50 mg/kg) leads to potent inhibition of in vivo tumor growth in a xenograft mouse model of human ovarian cancer, and the combination of beta-lapachone and taxol produces a synergistic induction of apoptosis. [6] In normal and diabetic (db/db) mice, treatment of beta-lapachone results in a faster healing process than vehicle only. [3]


Kinase Assay:
- Collapse

Topoisomerase I Catalytic Actioity Assay [1]:

Topoisomerase I Catalytic Actioity Assay: The enzymatic activity is analyzed by the DNA unwinding assay. DNA topoisomerase I, from TopoGEN (1 unit, which is defined as the amount of enzyme that converts 0.5 μg of superhelical DNA to the relaxed state in 30 minutes at 37 °C), is incubated with 0.5 μg of 6x174 RF DNA, in the presence or absence of Beta-Lapachone, in 20 μL of relaxation buffer (50 mM Tris (pH 7.5). 50 mM KCI, 10 mM MgCl2, 0.5 mM dithiothreitol, 0.5 mM EDTA, 30 μg/mL bovine serum albumin) for 30 minutes at 37 °C. Reactions are stopped by adding 1% SDS and proteinase K (50 μg/mL). After an additional 1-hour incubation at 37 °C, the products are separated by electrophoresis in 1% agarose gel in TAE buffer (0.04 M tris acetate, 0.001 M EDTA). The gel is stained with ethidium bromide after electrophoresis. The photographic negative is scanned with an NIH image analysis system.
Cell Research:[2]
- Collapse
  • Cell lines: HL-60, PC-3, DU145, and LNCaP cells
  • Concentrations: 0.005 to 50 μM
  • Incubation Time: 12 hours
  • Method: IC50 calculations for each cell line are determined by DNA amount (IS) and anchorage-dependent colony formation (CF) assays. For the CF assay, cells are seeded at 500 viable cells/well in 6-well plates and incubated overnight, then treated with equal volumes of media containing beta-lapachone at final concentrations ranging from 0.005 to 50 μM in half-log increments (controls were treated with 0.25% DMSO, equivalent to the highest dose of beta-lapachonc used) for 4 hour or for continuous 12-hour exposures. Plates (3 wells/condition) are stained with crystal violet, and colonies of >50 normal-appearing cells are enumerated. IC50 values for various cells are calculated using drug doses with numbers of colonies surrounding 50% of control. For DNA assays, plates are harvested for IC50 determinations 8 days after treatment using a CytoFluor 2350 fluorescence measurement system. Six-well samplings are included in the calculation of DNA fluor units for each dose. A graph of beta-lapachone dose versus percentage control DNA in fluor units is used to calculate each IC50. All experiments are repeated at least twice, each in duplicate.
    (Only for Reference)
Animal Research:[6]
- Collapse
  • Animal Models: Human ovarian cancer cells (36M2) are established in nude mice.
  • Dosages: 25–50 mg/kg
  • Administration: Intraperitoneal administration
    (Only for Reference)

Solubility (25°C)

In vitro DMSO 33 mg/mL warmed (136.21 mM)
Water Insoluble
Ethanol '10 mg/mL

* Please note that Selleck tests the solubility of all compounds in-house, and the actual solubility may differ slightly from published values. This is normal and is due to slight batch-to-batch variations.

Chemical Information

Molecular Weight 242.27


CAS No. 4707-32-8
Storage powder
in solvent
Synonyms β-Lapachone, ARQ-501
Smiles CC1(CCC2=C(O1)C3=CC=CC=C3C(=O)C2=O)C

In vivo Formulation Calculator (Clear solution)

Step 1: Enter information below (Recommended: An additional animal making an allowance for loss during the experiment)
Dosage mg/kg Average weight of animals g Dosing volume per animal ul Number of animals
Step 2: Enter the in vivo formulation ()
% DMSO % % Tween 80 % ddH2O

Bio Calculators

Molarity Calculator

Molarity Calculator

Calculate the mass, volume or concentration required for a solution. The Selleck molarity calculator is based on the following equation:

Mass (mg) = Concentration (mM) × Volume (mL) × Molecular Weight (g/mol)

  • Mass
    Molecular Weight

*When preparing stock solutions, please always use the batch-specific molecular weight of the product found on the via label and MSDS / COA (available on product pages).

Dilution Calculator

Dilution Calculator

Calculate the dilution required to prepare a stock solution. The Selleck dilution calculator is based on the following equation:

Concentration (start) x Volume (start) = Concentration (final) x Volume (final)

This equation is commonly abbreviated as: C1V1 = C2V2 ( Input Output )

  • C1

* When preparing stock solutions always use the batch-specific molecular weight of the product found on the vial label and MSDS / COA (available online).

The Serial Dilution Calculator Equation

  • Serial Dilutions

  • Computed Result

  • C1=C0/X C1: LOG(C1):
    C2=C1/X C2: LOG(C2):
    C3=C2/X C3: LOG(C3):
    C4=C3/X C4: LOG(C4):
    C5=C4/X C5: LOG(C5):
    C6=C5/X C6: LOG(C6):
    C7=C6/X C7: LOG(C7):
    C8=C7/X C8: LOG(C8):
Molecular Weight Calculator

Molecular Weight Calculator

Enter the chemical formula of a compound to calculate its molar mass and elemental composition:

Total Molecular Weight: g/mol

Tip: Chemical formula is case sensitive. C10H16N2O2 c10h16n2o2

Instructions to calculate molar mass (molecular weight) of a chemical compound:

To calculate molar mass of a chemical compound, please enter its chemical formula and click 'Calculate'.

Definitions of molecular mass, molecular weight, molar mass and molar weight:

Molecular mass (molecular weight) is the mass of one molecule of a substance and is expressed in the unified atomic mass units (u). (1 u is equal to 1/12 the mass of one atom of carbon-12)
Molar mass (molar weight) is the mass of one mole of a substance and is expressed in g/mol.

Molarity Calculator

Mass Concentration Volume Molecular Weight

Tech Support

Answers to questions you may have can be found in the inhibitor handling instructions. Topics include how to prepare stock solutions, how to store inhibitors, and issues that need special attention for cell-based assays and animal experiments.

Handling Instructions

Tel: +1-832-582-8158 Ext:3

If you have any other enquiries, please leave a message.

  • * Indicates a Required Field

Topoisomerase Signaling Pathway Map

Related Topoisomerase Products

Tags: buy Beta-Lapachone | Beta-Lapachone supplier | purchase Beta-Lapachone | Beta-Lapachone cost | Beta-Lapachone manufacturer | order Beta-Lapachone | Beta-Lapachone distributor
Cell Lines Assay Type Concentration Incubation Time Formulation Activity Description PMID