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Activators & Inhibitors
Chemical Modulators

SB431542 #14775

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SB431542: Image 1
Chemical structure of SB431542.
SB431542: Image 2
Western blot analysis of extracts from HT-1080 cells, serum-starved overnight and untreated (-) or treated with Human Transforming Growth Factor β1 (hTGF-β1) #8915 (10 ng/ml, 30 min; +) either with or without SB431542 pre-treatment (1 hr, indicated concentrations), using Phospho-Smad2 (Ser465/467)/Smad3 (Ser423/425) (D27F4) Rabbit mAb #8828 (upper) and Smad2/3 (D7G7) XP® Rabbit mAb #8685 (lower).

Product Usage Information

SB431542 is supplied as a lyophilized powder. For a 10 mM stock, reconstitute the 1 mg in 260.15 μl DMSO. Working concentrations and length of treatment can vary depending on the desired effect, but it is typically used as a pretreatment at 1-10 μM for 0.5-2 hr prior to treating with a stimulator. It can also be used alone, with varying treatment times lasting up to 24 hr.


Store lyophilized or in solution at -20ºC, desiccated. Protect from light. In lyophilized form, the chemical is stable for 24 months. Once in solution, use within 3 months to prevent loss of potency. Aliquot to avoid multiple freeze/thaw cycles.

Product Description

Molecular Weight 384.4 g/mol
Purity >98%
Molecular Formula C22H16N4O3
CAS 301836-41-9
Solubility Soluble in DMSO at 30mg/ml and EtOH at 3mg/ml


SB431542 is a potent and selective ATP-competitive inhibitor of the transforming growth factor β1 (TGF-β1) activin receptor-like kinases (ALK) -4, -5, and -7 (1-3). Research studies using cell-free kinase assays show that SB431542 inhibits ALK4 and ALK5 with IC50 values of 140 nM and 94 nM, respectively, and ALK7 with slightly less potency (2,3). The SB431542 inhibitor displays a 100-fold greater selectivity for ALK5 than 25 other kinases, including p38 MAPK and JNK1 (3). SB431542 inhibits Smad2 signaling induced by TGF-β and activin, but has no effect on BMP-induced Smad1 activation mediated by ALK -2, -3, and -6 (3,4). Additional studies show that SB431542 enhances the proliferation and integrity of ESC-derived endothelial cells (5).
  1. Callahan, J.F. et al. (2002) J Med Chem 45, 999-1001.
  2. Laping, N.J. et al. (2002) Mol Pharmacol 62, 58-64.
  3. Inman, G.J. et al. (2002) Mol Pharmacol 62, 65-74.
  4. Daly, A.C. et al. (2008) Mol Cell Biol 28, 6889-902.
  5. Watabe, T. et al. (2003) J Cell Biol 163, 1303-11.

Limited Uses

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Products are labeled with For Research Use Only or a similar labeling statement and have not been approved, cleared, or licensed by the FDA or other regulatory foreign or domestic entity, for any purpose. Customer shall not use any Product for any diagnostic or therapeutic purpose, or otherwise in any manner that conflicts with its labeling statement. Products sold or licensed by CST are provided for Customer as the end-user and solely for research and development uses. Any use of Product for diagnostic, prophylactic or therapeutic purposes, or any purchase of Product for resale (alone or as a component) or other commercial purpose, requires a separate license from CST. Customer shall (a) not sell, license, loan, donate or otherwise transfer or make available any Product to any third party, whether alone or in combination with other materials, or use the Products to manufacture any commercial products, (b) not copy, modify, reverse engineer, decompile, disassemble or otherwise attempt to discover the underlying structure or technology of the Products, or use the Products for the purpose of developing any products or services that would compete with CST products or services, (c) not alter or remove from the Products any trademarks, trade names, logos, patent or copyright notices or markings, (d) use the Products solely in accordance with CST Product Terms of Sale and any applicable documentation, and (e) comply with any license, terms of service or similar agreement with respect to any third party products or services used by Customer in connection with the Products.

For Research Use Only. Not For Use In Diagnostic Procedures.
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To Purchase # 14775
Cat. # Size Qty. Price
1 mg
$ 115