RSK4-IN-1

• CAT Number: I045338
• CAS Number: 2755819-10-2
• Molecular Formula: C19H20F2N4O3
• Molecular Weight: 390.38
• Purity: ≥95%
• Synonyms: 1-cyclopentyl-7-(3,5-difluoro-4-hydroxyanilino)-4,4-dimethylpyrimido[4,5-d][1,3]oxazin-2-one
• InChI: InChI=1S/C19H20F2N4O3/c1-19(2)12-9-22-17(23-10-7-13(20)15(26)14(21)8-10)24-16(12)25(18(27)28-19)11-5-3-4-6-11/h7-9,11,26H,3-6H2,1-2H3,(H,22,23,24)
• InChIKey: MVDARJWPZGHODF-UHFFFAOYSA-N
• SMILES: CC1(C2=CN=C(N=C2N(C(=O)O1)C3CCCC3)NC4=CC(=C(C(=C4)F)O)F)C

RSK4‑IN‑1 (Cat No.: I045338) is a highly potent and selective small-molecule inhibitor of ribosomal S6 kinase 4 (RSK4), with an IC₅₀ of approximately 9.5 nM. It appears as an off‑white to light‑yellow solid (molecular weight ~390.38 Da; CAS 2755819‑10‑2) and shows antitumor efficacy in preclinical models. By blocking RSK4-mediated phosphorylation, it disrupts downstream MAPK signaling and cell proliferation—especially in esophageal squamous cell carcinoma—while sparing other RSK isoforms. RSK4‑IN‑1 serves as a valuable research tool for exploring RSK4’s role in cancer biology.

Reference

[1]. Yuan Y, et al. Discovery, Optimization, and Structure-Activity Relationship Study of Novel and Potent RSK4 Inhibitors as Promising Agents for the Treatment of Esophageal Squamous Cell Carcinoma. J Med Chem. 2021 Sep 23;64(18):13572-13587.
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