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SB525334(TGF-beta1) receptor inhibitor


Catalog No. A5602
Size Price Stock Qty
10mM (in 1mL DMSO) $50.00 In stock
Evaluation Sample $28.00 In stock
5mg $50.00 In stock
25mg $150.00 In stock
100mg $480.00 In stock

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Sample solution is provided at 25 µL, 10mM.

Quality Control

Chemical structure


Related Biological Data


Related Biological Data


Biological Activity

Description SB525334 is a potent and selective inhibitor of TGFβ receptor I (ALK5) with IC50 of 14.3 nM, is 4-fold less potent to ALK4 than ALK5 and inactive to ALK2, 3, and 6.
Targets TGF-β1 (ALK5)          
IC50 14.3 nM          


Kinase experiment [1]:

Kinase assay

To determine the potency of SB525334, purified GST-tagged kinase domain of ALK5 was incubated with purified GST-tagged full-length Smad3 in the presence of 33P-γATP and different concentrations of SB525334. The readout is radioactively labeled Smad3. To determine the selectivity of SB525334, purified GST-tagged kinase domain of ALK2 and ALK4 were incubated with GST-tagged full-length Smad1 and Smad3, respectively, in the presence of different concentrations of SB525334. IC50 values were calculated.

Cell experiment [1]:

Cell lines

Human renal proximal tubule epithelial (RPTE) cells

Preparation method

The solubility of this compound in DMSO is > 10 mM. General tips for obtaining a higher concentration: Please warm the tube at 37 °C for 10 minutes and/or shake it in the ultrasonic bath for a while. Stock solution can be stored below -20 °C for several months.

Reaction Conditions

1 μM; 1 hr


In RPTE cells, SB525334 reduced endogenous TGF-β1 signaling.

Animal experiment [2]:

Animal models

Bleomycin-induced pulmonary fibrosis in female Eker rats

Dosage form

10 mg/kg/day; p.o.


In Eker rats, SB525334 significantly decreased uterine mesenchymal tumor incidence, multiplicity and size.

Other notes

Please test the solubility of all compounds indoor, and the actual solubility may slightly differ with the theoretical value. This is caused by an experimental system error and it is normal.


[1]. Grygielko ET, Martin WM, Tweed C, Thornton P, Harling J, Brooks DP, Laping NJ. Inhibition of gene markers of fibrosis with a novel inhibitor of transforming growth factor-beta type I receptor kinase in puromycin-induced nephritis. J Pharmacol Exp Ther. 2005 Jun;313(3):943-51.

[2]. Laping NJ, Everitt JI, Frazier KS, Burgert M, Portis MJ, Cadacio C, Gold LI, Walker CL. Tumor-specific efficacy of transforming growth factor-beta RI inhibition in Eker rats. Clin Cancer Res. 2007 May 15;13(10):3087-99.

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Chemical Properties

Cas No. 356559-20-1 SDF Download SDF
Chemical Name 6-[2-tert-butyl-5-(6-methylpyridin-2-yl)-1H-imidazol-4-yl]quinoxaline
Canonical SMILES CC1=CC=CC(=N1)C2=C(N=C(N2)C(C)(C)C)C3=CC4=NC=CN=C4C=C3
Formula C21H21N5 M.Wt 343.42
Solubility Soluble in DMSO > 10 mM Storage Store at -20°C
General tips No
Shipping Condition No


SB525334 is a potent inhibitor of transforming growth factor-beta1 (TGF-beta1) receptor, activin receptor-like kinase (ALK5). It specifically inhibits ALK5 with IC50 value of 14.3nM, which shows 4-fold higher potency against ALK4 [1].

SB525334 has been demonstrated to reduce smad2/3 nuclear fluorescence induced by TGF-beta1 in human renal proximal tubule epithelial (RPTE) cells. Additionally, SB525334 inhibits TGF-beta1 mediated procollagen and PAI-1 expression in human renal carcinoma cells A498 [1].

SB525334?dose-dependently reduces Urinary protein, procollagen alpha1(I) mRNA and?procollagen alpha1(III) mRNA when administered?orally in acute puromycin aminonucleoside (PAN) rat model of renal disease [1].

[1] Grygielko ET1,?Martin WM,?Tweed C,?Thornton P,?Harling J,?Brooks DP,?Laping NJ. Inhibition of gene markers of fibrosis with a novel inhibitor of transforming growth factor-beta type I receptor kinase in puromycin-induced nephritis. J Pharmacol Exp Ther.?2005 Jun;313(3):943-51.