R406
Based on 37 publication(s) in Google Scholar
R406 is an orally available and competitive Syk/FLT3 inhibitor for ATP binding with a Ki of 30 nM, potently inhibits Syk kinase activity in vitro with an IC50 of 41 nM, measured at an ATP concentration corresponding to its Km value. R406 reduces immune complex-mediated inflammation. R406 also inhibits Lyn (IC50=63 nM) and Lck (IC50=37 nM).
For research use only. We do not sell to patients.
- Purity: 97.91%
- CAS No.: 841290-81-1
- Formula: C28H29FN6O8S
- Molecular Weight:628.63
-
Storage:
4°C, sealed storage, away from moisture
* In solvent : -80°C, 6 months; -20°C, 1 month (sealed storage, away from moisture)
Publications Citing Use of MedChemExpress (MCE) R406
More- Nature. 2026 Jan;649(8098):1032-1041. [Abstract]
- Cell. 2018 Oct 4;175(2):442-457.e23. [Abstract]
- Adv Mater. 2024 Mar 15:e2311283. [Abstract]
- Nat Commun. 2022 Apr 19;13(1):2136. [Abstract]
- Exp Hematol Oncol. 2022 Nov 8;11(1):88. [Abstract]
- J Adv Res. 2026 Jan 22:S2090-1232(26)00069-X. [Abstract]
- Redox Biol. 2022 Oct:56:102461. [Abstract]
- Sci Transl Med. 2018 Jul 18;10(450):eaaq1093. [Abstract]
- Theranostics. 2021 May 24;11(15):7308-7321. [Abstract]
- Cell Rep Med. 2025 Jan 16:101922. [Abstract]
- Cell Death Dis. 2025 Aug 7;16(1):595. [Abstract]
- Cell Commun Signal. 2024 Apr 2;22(1):210. [Abstract]
- J Neuroinflammation. 2024 Dec 3;21(1):318. [Abstract]
- Mater Today Bio. 2024 Mar 22:26:101037. [Abstract]
- Arthritis Rheumatol. 2018 Sep;70(9):1419-1428. [Abstract]
- Blood Adv. 2024 Nov 12;8(21):5653-5662. [Abstract]
- Cell Rep. 2023 Mar 20;42(3):112275. [Abstract]
- Atherosclerosis. 2019 Oct;289:132-142. [Abstract]
- Life Metab. 2025 Jan 29;4(2):loaf002. [Abstract]
- Front Pharmacol. 2022 May 5;13:885053. [Abstract]
- ACS Infect Dis. 2026 Jun 25. [Abstract]
- iScience. 2024 Jun 28;27(7):110415. [Abstract]
- iScience. 2024 Mar 27;27(4):109607. [Abstract]
- iScience. 2024 Jan 11;27(2):108869. [Abstract]
- ACS Infect Dis. 2021 Mar 12;7(3):661-671. [Abstract]
- J Biol Chem. 2018 Apr 27;293(17):6410-6433. [Abstract]
- Mol Immunol. 2024 Jul 31:173:88-98. [Abstract]
- BMC Cardiovasc Disord. 2024 Jul 12;24(1):354. [Abstract]
- J Pharmacol Sci. 2017 May;134(1):29-36. [Abstract]
- Scand J Immunol. 2024 Apr 26:e13371. [Abstract]
- SSRN. 2025 Dec 2.
- Stony Brook University. 2025.
- bioRxiv. 2024 Apr 9.
- SSRN. 2023 Jun 29.
- bioRxiv. 2022 Dec 21, 519945.
- Ann Transl Med. 2019 Dec;7(23):758. [Abstract]
- Nihon University. School of Medicine. 2014 Mar.
-
Cell Migration/Invasion Assay
-
WB
-
Flow Cytometry
-
IP
-
WB
Biological Activity
Ki: 30 nM (Syk)[1]
IC50: 41 nM (Syk)[1]
FLT3[1]
IC50: 63 nM (Lyn), 37 nM (Lck)[2]
R406 inhibits adenosine A3 receptor (IC50=0.081 μM), adenosine transporter (IC50=1.84 μM), and monoamine transporter (IC50=2.74 μM)[1].
R406 inhibits Huh7 hepatocyte, A549 epithelial, and H1299 lung cancer lines with EC50s of 15.1, 2.9 and 6.3 μM, respectively[1].
R406 inhibits phosphorylation of Syk substrate LAT in mast cells and BLNK/SLP65 in B cells[1].
MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.
-
Cell Line:Cultured human mast cells (CHMC)
-
Concentration:0.016, 0.08, 0.4, 2 µM
-
Incubation Time:40 minutes
-
Result:Inhibited all other kinases tested at 5 to 100 fold less potency than Syk as judged by phosphorylation of target proteins.
MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.
-
Animal Model:Female Balb/c mice (6-8 weeks) with CAIA[1]
-
Dosage:5 and 10 mg/kg
-
Administration:Administered orally, b.i.d, for 14 days, starting 4 hours after antibody challenge on day 0.
-
Result:Reduced inflammation and swelling, and the arthritis progressed more slowly in treated animals than in vehicle controls.
-
Animal Model:Female C57BL/6 mice with arthritis[1]
-
Dosage:10 mg/kg
-
Administration:Administered orally one hour before serum injection; b.i.d; for 13 days
-
Result:Delayed the onset and reduced the severity of clinical arthritis. Paw thickening and clinical arthritis were reduced by approximately 50%.
Chemical Information
-
CAS No. 841290-81-1
-
Appearance Solid
-
Molecular Weight 628.63
-
Formula C28H29FN6O8S
-
Color Light yellow to khaki
-
SMILES
COC1=CC(NC2=NC(NC3=NC(N4)=C(C=C3)OC(C)(C)C4=O)=C(C=N2)F)=CC(OC)=C1OC.OS(C5=CC=CC=C5)(=O)=O
-
Shipping
Room temperature in continental US; may vary elsewhere.
-
Storage
4°C, sealed storage, away from moisture
* In solvent : -80°C, 6 months; -20°C, 1 month (sealed storage, away from moisture)
Publications (37)
-
Journal Impact Factor
-
Most Recent
-
Nature
2026 Jan;649(8098):1032-1041. PMID: 41299171 -
Cell
2018 Oct 4;175(2):442-457.e23. PMID: 30290143
R406 purchased from MedChemExpress. Usage Cited in: Cell. 2018 Oct 4;175(2):442-457.e23. [Abstract]
Syk inhibitors (R406 (5 μM) and Piceatannol) are added during the induction of trastuzumab-dependent BT-474 phagocytosis. The binding of the phagosome marker Rab7 to AIM2 in macrophages are evaluated by co-immunoprecipitation.
-
Adv Mater
Glycocalyx-Mimicking Nanoparticles with Differential Organ Selectivity for Drug Delivery and Therapy. [Abstract]2024 Mar 15:e2311283. PMID: 38489768 -
Nat Commun
A loss-of-adhesion CRISPR-Cas9 screening platform to identify cell adhesion-regulatory proteins and signaling pathways. [Abstract]2022 Apr 19;13(1):2136. PMID: 35440579
R406 purchased from MedChemExpress. Usage Cited in: Nat Commun. 2022 Apr 19;13(1):2136. [Abstract]
Comparison of pharmacological inhibitors with the corresponding guides of positive and negative controls for BCR-controlled adhesion. Top plots: Namalwa cells pretreated with 100 nM ibrutinib (BTK inhibitor), 1 μM R406 (Fostamatinib, SYK inhibitor, 1 ), 100 nM wortmannin (pan-PI3K inhibitor), 50 μM PD-98059 (MEK1/2 inhibitor), 2.5 μM MK-2206 (AKT1/2/3 inhibitor), or DMSO control, were stimulated with αIgM or PMA, and allowed to adhere to fibronectin-coated surfaces. Bar graphs are presented as normalized mean + SEM (100% = untreated αIgM-stimulated cells). Bottom plots: MA plots of αIgM-induced adhesion relative to PMA-induced adhesion; the guides of the corresponding genes targeted by the inhibitors of the top plots are highlighted.
-
Exp Hematol Oncol
Gut fungi enhances immunosuppressive function of myeloid-derived suppressor cells by activating PKM2-dependent glycolysis to promote colorectal tumorigenesis. [Abstract]2022 Nov 8;11(1):88. PMID: 36348389
R406 purchased from MedChemExpress. Usage Cited in: Exp Hematol Oncol. 2022 Nov 8;11(1):88. [Abstract]
R406 (1-2 μM; 18-24 h) markedly inhibited C. tropicalis-induced PKM2 Tyr105 phosphorylation and PKM2 nuclear translocation in MDSCs by suppressing Syk.
-
J Adv Res
METTL3 promotes neutrophil extracellular trap formation via SYK/ERK/MEK signaling during acute lung injury. [Abstract]2026 Jan 22:S2090-1232(26)00069-X. PMID: 41579954 -
Redox Biol
HDAC11 negatively regulates antifungal immunity by inhibiting Nos2 expression via binding with transcriptional repressor STAT3. [Abstract]2022 Oct:56:102461. PMID: 36087429 -
Sci Transl Med
PP2A inhibition is a druggable MEK inhibitor resistance mechanism in KRAS-mutant lung cancer cells. [Abstract]2018 Jul 18;10(450):eaaq1093. PMID: 30021885 -
Theranostics
Adjuvant-free peptide vaccine targeting Clec9a on dendritic cells can induce robust antitumor immune response through Syk/IL-21 axis. [Abstract]2021 May 24;11(15):7308-7321. PMID: 34158852
R406 purchased from MedChemExpress. Usage Cited in: Theranostics. 2021 May 24;11(15):7308-7321. [Abstract]
The induction of IL-21 secretion by CBP-12-OVA was inhibited by R406, an inhibitor of Syk phosphorylation. FL-DCs were incubated with 2.5 µM R406 for 1 h, and then cultured with 100 µg/mL of the indicated peptides for 6 h at 37 °C. IL-21 positive frequency was determined by ICS assay.
-
Cell Rep Med
MFGE8 induces anti-PD-1 therapy resistance by promoting extracellular vesicle sorting of PD-L1. [Abstract]2025 Jan 16:101922. PMID: 39842432 -
Cell Death Dis
Activation of AKT via a dual mechanism enhances the susceptibility of melanoma cells to glucose deprivation. [Abstract]2025 Aug 7;16(1):595. PMID: 40774947 -
Cell Commun Signal
Mitochondria-mediated ferroptosis induced by CARD9 ablation prevents MDSCs-dependent antifungal immunity. [Abstract]2024 Apr 2;22(1):210. PMID: 38566195 -
J Neuroinflammation
Metformin attenuates central sensitization by regulating neuroinflammation through the TREM2-SYK signaling pathway in a mouse model of chronic migraine. [Abstract]2024 Dec 3;21(1):318. PMID: 39627853 -
Mater Today Bio
2024 Mar 22:26:101037. PMID: 38586870 -
Arthritis Rheumatol
Translational Biomarkers and Ex Vivo Models of Joint Tissues as a Tool for Drug Development in Rheumatoid Arthritis. [Abstract]2018 Sep;70(9):1419-1428. PMID: 29669391 -
Blood Adv
Activating pyruvate kinase improves red blood cell integrity by reducing band 3 tyrosine phosphorylation. [Abstract]2024 Nov 12;8(21):5653-5662. PMID: 39265169 -
Cell Rep
Pharmacological boosting of cGAS activation sensitizes chemotherapy by enhancing antitumor immunity. [Abstract]2023 Mar 20;42(3):112275. PMID: 36943864 -
Atherosclerosis
Inhibition of vascular neointima hyperplasia by FGF21 associated with FGFR1/Syk/NLRP3 inflammasome pathway in diabetic mice. [Abstract]2019 Oct;289:132-142. PMID: 31513948 -
Life Metab
Intermittent fasting inhibits platelet activation and thrombosis through the intestinal metabolite indole-3-propionate. [Abstract]2025 Jan 29;4(2):loaf002. PMID: 40078933 -
Front Pharmacol
Inhibition of Spleen Tyrosine Kinase Restores Glucocorticoid Sensitivity to Improve Steroid-Resistant Asthma. [Abstract]2022 May 5;13:885053. PMID: 35600871 -
ACS Infect Dis
Coordinated Regulation of TLR2 Signaling by Neu1 Sialidase and the Siglec-5/Siglec-14 Receptor Pair During Mycoplasma pneumoniae Infection. [Abstract]2026 Jun 25. PMID: 42350323 -
iScience
Decoding sunitinib resistance in ccRCC: Metabolic-reprogramming-induced ABAT and GABAergic system shifts. [Abstract]2024 Jun 28;27(7):110415. PMID: 39100925 -
iScience
SWI/SNF complex-mediated chromatin remodeling in Candida glabrata promotes immune evasion. [Abstract]2024 Mar 27;27(4):109607. PMID: 38632999 -
iScience
Heat-killed Mycobacterium tuberculosis induces trained immunity in vitro and in vivo administered systemically or intranasally. [Abstract]2024 Jan 11;27(2):108869. PMID: 38318361 -
ACS Infect Dis
Sialylated Lipooligosaccharide Contributes to Glaesserella parasuis Penetration of Porcine Respiratory Epithelial Barrier. [Abstract]2021 Mar 12;7(3):661-671. PMID: 33645216 -
J Biol Chem
Aspartyl proteases in Candida glabrata are required for suppression of the host innate immune response. [Abstract]2018 Apr 27;293(17):6410-6433. PMID: 29491142 -
Mol Immunol
Tanshinone I limits inflammasome activation of macrophage via docking into Syk to alleviate DSS-induced colitis in mice. [Abstract]2024 Jul 31:173:88-98. PMID: 39088935 -
BMC Cardiovasc Disord
Sodium tanshinone IIA sulfonate protects vascular relaxation in ApoE-knockout mice by inhibiting the SYK-NLRP3 inflammasome-MMP2/9 pathway. [Abstract]2024 Jul 12;24(1):354. PMID: 38992615 -
J Pharmacol Sci
Effects of a spleen tyrosine kinase inhibitor on progression of the lupus nephritis in mice. [Abstract]2017 May;134(1):29-36. PMID: 28479222
R406 purchased from MedChemExpress. Usage Cited in: J Pharmacol Sci. 2017 May;134(1):29-36. [Abstract]
The effects of R406 treatment on the phosphorylation of 3BP2 and p38MAPK in white blood cells from the spleens of NZB/W F1 mice. (A) The phosphorylation of the 3BP2 and (B) the phosphorylation of p38MAPK in the renal cortex of control and R406-treated mice.
-
Scand J Immunol
Isoliquiritigenin limits inflammasome activation of macrophage via docking into Syk to alleviate murine non-alcoholic fatty liver disease. [Abstract]2024 Apr 26:e13371. PMID: 38671579 -
-
-
-
-
-
Ann Transl Med
Upregulated miR-155 inhibits inflammatory response induced by C. albicans in human monocytes derived dendritic cells via targeting p65 and BCL-10. [Abstract]2019 Dec;7(23):758. PMID: 32042774 -
Solvent & Solubility
DMSO : 60 mg/mL (95.45 mM; ultrasonic and warming and heat to 60°C; Hygroscopic DMSO has a significant impact on the solubility of product, please use newly opened DMSO)
Please refer to the solubility information to select the appropriate solvent. Once prepared, please aliquot and store the solution to prevent product inactivation from repeated freeze-thaw cycles.
Storage method and period of stock solution: -80°C, 6 months; -20°C, 1 month (sealed storage, away from moisture). When stored at -80°C, please use it within 6 months. When stored at -20°C, please use it within 1 month.
Please refer to the solubility information to select the appropriate solvent. Once prepared, please aliquot and store the solution to prevent product inactivation from repeated freeze-thaw cycles.
Storage method and period of stock solution: -80°C, 6 months; -20°C, 1 month (sealed storage, away from moisture). When stored at -80°C, please use it within 6 months. When stored at -20°C, please use it within 1 month.
Concentration (start) × Volume (start) = Concentration (final) × Volume (final)
Select the appropriate dissolution method based on your experimental animal and administration route.
- For the following dissolution methods, please ensure to first prepare a clear stock solution using an In Vitro approach and then sequentially add co-solvents:
- To ensure reliable experimental results, the clarified stock solution can be appropriately stored based on storage conditions. As for the working solution for In Vivo experiments, it is recommended to prepare freshly and use it on the same day.
- The percentages shown for the solvents indicate their volumetric ratio in the final prepared solution. If precipitation or phase separation occurs during preparation, heat and/or sonication can be used to aid dissolution.
Add each solvent one by one: 10% DMSO 40% PEG300 5% Tween-80 45% Saline
Solubility: ≥ 2.5 mg/mL (3.98 mM); Clear solution
This protocol yields a clear solution of ≥ 2.5 mg/mL (saturation unknown).
Taking 1 mL working solution as an example, add 100 μL DMSO stock solution (25.0 mg/mL) to 400 μL PEG300, and mix evenly; then add 50 μL Tween-80 and mix evenly; then add 450 μL Saline to adjust the volume to 1 mL.
Preparation of Saline: Dissolve 0.9 g sodium chloride in ddH₂O and dilute to 100 mL to obtain a clear Saline solution.
Add each solvent one by one: 10% DMSO 90% (20% SBE-β-CD in Saline)
Solubility: 2.5 mg/mL (3.98 mM); Suspended solution; Need ultrasonic
This protocol yields a suspended solution of 2.5 mg/mL. Suspended solution can be used for oral and intraperitoneal injection.
Taking 1 mL working solution as an example, add 100 μL DMSO stock solution (25.0 mg/mL) to 900 μL 20% SBE-β-CD in Saline, and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C, storage for one week): 2 g SBE-β-CD powder is dissolved in 10 mL Saline, completely dissolve until clear.
Please enter the basic information of animal experiments:
-
-
-
-
Recommended: Prepare an additional quantity of animals to account for potential losses during experiments.
Please enter your animal formula composition:
-
%DMSO +
Recommended: Keep the proportion of DMSO in working solution below 2% if your animal is weak.
-
%+
-
+%Tween-80 + +
-
%Saline +
The co-solvents required include: DMSO, . All of co-solvents are available by MedChemExpress (MCE). , Tween 80. All of co-solvents are available by MedChemExpress (MCE).
Working solution concentration: 0.22 mg/mL
Method for preparing stock solution: mg drug dissolved in μL DMSO. Stock solution concentration: mg/mL. * In solvent : -80°C, 6 months; -20°C, 1 month (sealed storage, away from moisture)
1. Take μL DMSO stock solution;
2. Add μL .
μL , mix evenly;
3. Then add μL Tween 80, mix evenly;
4. Then add μL
Please ensure that the stock solution in the first step is dissolved to a clear state, and add co-solvents in sequence. You can use ultrasonic heating (ultrasonic cleaner, recommended frequency 20-40 kHz), vortexing, etc. to assist dissolution.
Purity & Documentation
-
Data Sheet (277 KB)
-
SDS (393 KB)
- English - EN (393 KB)
- Français - FR (393 KB)
- Deutsch - DE (393 KB)
- Norwegian - NO (393 KB)
- Español - ES (393 KB)
- Swedish - SV (393 KB)
- Italian - IT (393 KB)
- Korean - KR (393 KB)
- Portuguese - PT (393 KB)
-
Handling Instructions (2659 KB)
References
[1]. Sylvia Braselmann, et al. R406, an orally available spleen tyrosine kinase inhibitor blocks fc receptor signaling and reduces immune complex-mediated inflammation. J Pharmacol Exp Ther. 2006 Dec;319(3):998-1008. [Content Brief]
[2]. Hoon-Suk Cha , et al. A novel spleen tyrosine kinase inhibitor blocks c-Jun N-terminal kinase-mediated gene expression in synoviocytes. J Pharmacol Exp Ther. 2006 May;317(2):571-8. [Content Brief]
Complete Stock Solution Preparation Table
Please refer to the solubility information to select the appropriate solvent. Once prepared, please aliquot and store the solution to prevent product inactivation from repeated freeze-thaw cycles.
Storage method and period of stock solution: -80°C, 6 months; -20°C, 1 month (sealed storage, away from moisture). When stored at -80°C, please use it within 6 months. When stored at -20°C, please use it within 1 month.
| Optional Solvent | Concentration Solvent Mass | 1 mg | 5 mg | 10 mg | 25 mg |
|---|---|---|---|---|---|
| DMSO | 1 mM | 1.5908 mL | 7.9538 mL | 15.9076 mL | 39.7690 mL |
| 5 mM | 0.3182 mL | 1.5908 mL | 3.1815 mL | 7.9538 mL | |
| 10 mM | 0.1591 mL | 0.7954 mL | 1.5908 mL | 3.9769 mL | |
| 15 mM | 0.1061 mL | 0.5303 mL | 1.0605 mL | 2.6513 mL | |
| 20 mM | 0.0795 mL | 0.3977 mL | 0.7954 mL | 1.9885 mL | |
| 25 mM | 0.0636 mL | 0.3182 mL | 0.6363 mL | 1.5908 mL | |
| 30 mM | 0.0530 mL | 0.2651 mL | 0.5303 mL | 1.3256 mL | |
| 40 mM | 0.0398 mL | 0.1988 mL | 0.3977 mL | 0.9942 mL | |
| 50 mM | 0.0318 mL | 0.1591 mL | 0.3182 mL | 0.7954 mL | |
| 60 mM | 0.0265 mL | 0.1326 mL | 0.2651 mL | 0.6628 mL | |
| 80 mM | 0.0199 mL | 0.0994 mL | 0.1988 mL | 0.4971 mL |