For research use only.
Catalog No.S7261 Synonyms: β-Lapachone, ARQ-501
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.
Selleck's Beta-Lapachone has been cited by 6 publications
Purity & Quality Control
Choose Selective Topoisomerase Inhibitors
|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.|
Beta-Lapachone inhibits DNA relaxation induced by DNA topoisomerase I in a dose-dependent manner.  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.  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.  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.  Beta-lapachone induces programmed necrosis of NQO1+ cancer cells by NQO1-dependent reactive oxygen species (ROS) formation and PARP1 hyperactivation. 
|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.  In normal and diabetic (db/db) mice, treatment of beta-lapachone results in a faster healing process than vehicle only. |
Topoisomerase I Catalytic Actioity Assay :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.
-  Li CJ, et al. J Biol Chem. 1993, 268(30), 22463-22468.
-  Planchon SM, et al. Cancer Res. 1995, 55(17), 3706-3711.
-  Kung HN, et al. Am J Physiol Cell Physiol. 2008, 295(4), C931-943.
|In vitro||DMSO||33 mg/mL warmed (136.21 mM)|
* 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.
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|
Working concentration： mg/ml；
Method for preparing DMSO master liquid: ： mg drug pre-dissolved in μL DMSO (Master liquid concentration mg/mL，)
Method for preparing in vivo formulation：Take μL DMSO master liquid, next addμL PEG300， mix and clarify, next addμL Tween 80，mix and clarify, next add μL ddH2O，mix and clarify.
1.Please make sure the liquid is clear before adding the next solvent.
2.Be sure to add the solvent(s) in order. You must ensure that the solution obtained, in the previous addition, is a clear solution before proceeding to add the next solvent. Physical methods such as vortex, ultrasound or hot water bath can be used to aid dissolving.
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)
*When preparing stock solutions, please always use the batch-specific molecular weight of the product found on the via label and SDS / COA (available on product pages).
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 )
* When preparing stock solutions always use the batch-specific molecular weight of the product found on the vial label and SDS / COA (available online).
Molecular Weight Calculator
Enter the chemical formula of a compound to calculate its molar mass and elemental composition:
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.
Clinical Trial Information
|NCT Number||Recruitment||interventions||Conditions||Sponsor/Collaborators||Start Date||Phases|
|NCT00524524||Completed||Drug: ARQ 501||Advanced Solid Tumors||ArQule Inc. (a wholly owned subsidiary of Merck Sharp and Dohme a subsidiary of Merck & Co. Inc.)||August 2007||Phase 1|
|NCT00622063||Completed||Drug: ARQ 501||Cancer||ArQule Inc. (a wholly owned subsidiary of Merck Sharp and Dohme a subsidiary of Merck & Co. Inc.)||December 2006||Phase 1|Phase 2|
|NCT00358930||Completed||Drug: ARQ 501||Head and Neck Neoplasms|Carcinoma Squamous Cell||ArQule Inc. (a wholly owned subsidiary of Merck Sharp and Dohme a subsidiary of Merck & Co. Inc.)||July 2006||Phase 2|
|NCT00102700||Completed||Drug: ARQ 501 in combination with gemcitabine||Pancreatic Cancer|Adenocarcinoma||ArQule Inc. (a wholly owned subsidiary of Merck Sharp and Dohme a subsidiary of Merck & Co. Inc.)||January 2005||Phase 2|
|NCT00099190||Completed||Drug: ARQ 501||Carcinoma||ArQule Inc. (a wholly owned subsidiary of Merck Sharp and Dohme a subsidiary of Merck & Co. Inc.)||December 2004||Phase 1|
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.
Tel: +1-832-582-8158 Ext:3
If you have any other enquiries, please leave a message.