1,5-Naphthyridine, 2-[3-(6-methyl-2-pyridinyl)-1H-pyrazol-4-yl]-, hydrochloride (1:1)

ALK5 inhibitor II is a cell permeable, selective inhibitor of the TGF-β type 1 activin like kinase receptor ALK5 (IC₅₀s = 4, 18, and 23 nM for ALK5 autophosphorylation, TGF-β cellular assay, and ALK5 binding in HepG2 cells, respectively).¹ This inhibitor demonstrated less potent activity (IC₅₀s > 16 μM) when tested against a panel of 9 related kinases, including p38 MAPK and GSK3.¹ At 25 μM, this compound has been used to induce stem cell pluripotency by replacing the reprogramming transcription factor Sox2 via inhibition of the TGF-β signaling pathway and induction of Nanog transcription.² This product is a hydrochloride form of the compound. A non-hydrochloride version of ALK5 inhibitor II is also available.

1. Gellibert, F., Wollven, J., Fouchet, M.H., et al. Identification of 1,5-naphthyridine derivatives as a novel series of potent and selective TGF-β type I receptor inhibitors J. Med. Chem. 47(18),4494-4506(2004).
2. Ichida, J.K., Blanchard, J., Lam, K., et al. A small-molecule inhibitor of Tgf-β signaling replaces Sox2 in reprogramming by inducing Nanog Cell Stem Cell 5(5),491-503(2009).