Catalog Number: 1987
Alternate Names: CI 940, LMB
Chemical Name: (2E,5S,6R,7S,9R,10E,12E,15R,16Z,18E)-19-[(2S,3S)-3,6-Dihydro-3-methyl-6-oxo-2H-pyran-2-yl]-17-ethyl-6-hydroxy-3,5,7,9,11,15-hexamethyl-8-oxo-2,10,12,16,18-nonadecapentaenoic acid
Biological Activity
Antifungal antibiotic that is an inhibitor of the nuclear export of proteins; acts by binding directly to and inhibiting CRM1/exportin-1. Inhibits the nuclear export of the HIV regulatory protein Rev and stabilizes p53. Antitumor in vitro and in vivo.
Technical Data
  • M.Wt:
  • Formula:
  • Solubility:
    Soluble in ethanol (supplied pre-dissolved in anhydrous ethanol, 27?g/ml)
  • Storage:
    Desiccate at -20°C
  • CAS No:
The technical data provided above is for guidance only. For batch specific data refer to the Certificate of Analysis. All Tocris products are intended for laboratory research use only.
Background References
  1. In vivo and in vitro anticancer activity of the structurally novel and highly potent antibiotic CI 940 and its hydroxy analog (PD 114,721).
    Roberts et al.
    Cancer Chemother.Pharmacol., 1986;16:95
  2. Leptomycin B is an inhibitor of nuclear export: inhibition of nucleocytoplasmic translocation of the human immunodeficiency virus type 1 (HIV-1) Rev protein and Rev-dependent mRNA.
    Wolff et al.
    Chem.Biol., 1997;4:139
  3. Nuclear export is required for degradation of endogenous p53 by MDM2 and human papillomavirus E6.
    Freedman and Levine
    Mol.Cell.Biol., 1998;18:7288
  4. Leptomycin B inhibition of signal-mediated nuclear export by direct binding to CRM1.
    Kudo et al.
    Exp.Cell Res., 1998;242:540

The citations listed below are publications that use Tocris products. Selected citations for Leptomycin B include:

Showing Results 1 - 2 of 2

  1. Proteasomal degradation of herpes simplex virus capsids in macrophages releases DNA to the cytosol for recognition by DNA sensors.
    Authors: Horan Et al.
    J Immunol
  2. A nuclear export signal in the matrix protein of Influenza A virus is required for efficient virus replication.
    Authors: Cao Et al.
    J Virol
Tocris Bioscience is the leading supplier of novel and exclusive tools for life science research with over 30 years' experience in the industry. Tocris is a Bio-Techne brand.

Order Details


Contact Information

Molarity Calculator
Calculate the mass, volume or concentration required for a solution

The molarity calculator is based on the following equation:

Mass (g) = Concentration (mol/L) x Volume (L) x Molecular Weight (g/mol)
An example of a molarity calculation using the molarity calculator:
What is the mass of compound required to make a 10 mM stock solution in 10 ml of water given that the molecular weight of the compound is 197.13 g/mol?

R&D Systems Guarantee

or select another batch:


Customer Information