1. Cell Cycle/DNA Damage
  2. IRE1
  3. 4μ8C

4μ8C  (Synonyms: IRE1 Inhibitor III)

Cat. No.: HY-19707 Purity: 98.78%
COA Handling Instructions

4μ8C (IRE1 Inhibitor III) is a small-molecule inhibitor of IRE1α.

For research use only. We do not sell to patients.

4μ8C Chemical Structure

4μ8C Chemical Structure

CAS No. : 14003-96-4

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Solid + Solvent
10 mM * 1 mL in DMSO
ready for reconstitution
USD 61 In-stock
10 mM * 1 mL in DMSO USD 61 In-stock
5 mg USD 55 In-stock
10 mg USD 77 In-stock
25 mg USD 132 In-stock
50 mg USD 209 In-stock
100 mg USD 319 In-stock
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Customer Review

Based on 33 publication(s) in Google Scholar

Top Publications Citing Use of Products

31 Publications Citing Use of MCE 4μ8C


    4μ8C purchased from MedChemExpress. Usage Cited in: Environ Toxicol. 2023 Apr 18.  [Abstract]

    4μ8C (20 μM; 1 h) significantly inhibits NaF-induced increased expression of p-IRE1 , GRP78 , p-TRAF2 , p-JNK, and LC3II/I in LS8 cells.

    4μ8C purchased from MedChemExpress. Usage Cited in: Toxins. 2020 Jan 16;12(1):55.  [Abstract]

    The effect of the IRE1 specific inhibitor 4μ8C on the expression of apoptosis-related proteins. The cells are exposed to FB1 with or without 4μ8C for 24 h, and the phosphorylation of JNK, Mcl-1, Bak, Bax, and Puma were analyzed by Western blotting. n = 3.
    • Biological Activity

    • Purity & Documentation

    • References

    • Customer Review


    4μ8C (IRE1 Inhibitor III) is a small-molecule inhibitor of IRE1α.

    In Vitro

    When applies to the media of ER stressed cultured cells, 4μ8C (IRE1 Inhibitor III) inhibits Xbp1 splicing in a concentration-dependent manner. 4μ8C dissociates slowly from IRE1, but ishout of inhibitor leads to rapid recovery of Xbp1 splicing in cells[1].The IRE1 endoribonuclease inhibitor 4μ8c prevents the splicing of the XBP1 mRNA in response to ER stress caused by mutant proinsulin production[2]. The inositol-requiring enzyme 1α (IRE1α) is a serine-threonine kinase that plays crucial roles in activating the unfolded protein response. 4μ8C treatment dramatically inhibits IL-4 production by CD4+ T cells under Th0 conditions because both the IL-4 levels in the culture supernatant and the percentage of IL-4 positive cells are reduced by 4μ8C treatment. In addition, both IL-5 and IL-13 production are significantly reduced upon treatment with 4μ8C[3].

    MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

    In Vivo

    4μ8c (IRE1 Inhibitor III) (i.p. injection; 10 mg/kg/day for 4 more weeks) leads to a significant reduction (45.2%) in atherosclerotic lesion area in en face aorta preparations. 4μ8c can effectively mitigate plaque development in mice[4].
    ? 4μ8C (orally; 10, 50, or 100 mg/kg) suppresses passive cutaneous anaphylaxis (PCA) in mice (ED50 = 25.1 mg/kg)[5].
    ? 4μ8C reverses the ER stress-dependent loss of several known RIDD targets, with an EC50 of approximately 4 μM, approximating that of inhibition of XBP1 target gene activation[1].

    MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

    Animal Model: ApoE-/- mice[4]
    Dosage: 10 mg/kg
    Administration: I.p. injection; daily; for 4 more weeks
    Result: Led to a significant reduction (45.2%) in atherosclerotic lesion area in en face aorta preparations.
    Molecular Weight






    CAS No.



    Room temperature in continental US; may vary elsewhere.

    Powder -20°C 3 years
    In solvent -80°C 1 year
    -20°C 6 months
    Solvent & Solubility
    In Vitro: 

    DMSO : ≥ 27 mg/mL (132.24 mM)

    *"≥" means soluble, but saturation unknown.

    Stock Solutions
    Concentration Solvent Mass 1 mg 5 mg 10 mg
    1 mM 4.8976 mL 24.4882 mL 48.9764 mL
    5 mM 0.9795 mL 4.8976 mL 9.7953 mL
    10 mM 0.4898 mL 2.4488 mL 4.8976 mL
    *Please refer to the solubility information to select the appropriate solvent.
    In Vivo:
    • 1.

      Add each solvent one by one:  10% DMSO    40% PEG300    5% Tween-80    45% Saline

      Solubility: ≥ 2.08 mg/mL (10.19 mM); Clear solution

    *All of the co-solvents are available by MedChemExpress (MCE).
    Purity & Documentation

    Purity: 98.78%

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    4μ8C Related Classifications

    Help & FAQs
    • Do most proteins show cross-species activity?

      Species cross-reactivity must be investigated individually for each product. Many human cytokines will produce a nice response in mouse cell lines, and many mouse proteins will show activity on human cells. Other proteins may have a lower specific activity when used in the opposite species.

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