JAK3-IN-6 is a novel potent, selective, and irreversible inhibitor of Janus Associated Kinase 3 (JAK3) with anti-inflammatory effects. It inhibits JAK3 with an IC50 of 0.15 nM. JAK3-IN-6 was 4300-fold selective for JAK3 over JAK1 in enzyme assays, 67-fold [interleukin (IL)-2 versus IL-6] or 140-fold [IL-2 versus erythropoietin or granulocyte-macrophage colony-stimulating factor (GMCSF)] selective in cellular reporter assays and >35-fold selective in human peripheral blood mononuclear cell assays (IL-7 versus IL-6 or GMCSF). In vivo, selective JAK3 inhibition was sufficient to block the development of inflammation in a rat model of rheumatoid arthritis, while sparing hematopoiesis.

Physicochemical Properties

Molecular Formula	C19H18N4O3
Molecular Weight	350.371223926544
Exact Mass	350.137
CAS #	1443235-95-7
Related CAS #	1443235-95-7
PubChem CID	89629876
Appearance	White to light yellow solid powder
LogP	2.7
Hydrogen Bond Donor Count	2
Hydrogen Bond Acceptor Count	5
Rotatable Bond Count	6
Heavy Atom Count	26
Complexity	553
Defined Atom Stereocenter Count	0
SMILES	O(CC)C(C1=CNC2C1=C(C1C=CC=C(C=1)NC(C(=C)C)=O)N=CN=2)=O
InChi Key	NJPHKVOXHRAPGJ-UHFFFAOYSA-N
InChi Code	InChI=1S/C19H18N4O3/c1-4-26-19(25)14-9-20-17-15(14)16(21-10-22-17)12-6-5-7-13(8-12)23-18(24)11(2)3/h5-10H,2,4H2,1,3H3,(H,23,24)(H,20,21,22)
Chemical Name	Ethyl 4-(3-methacrylamidophenyl)-7H-pyrrolo[2,3-d]pyrimidine-5-carboxylate
Synonyms	JAK3-IN-2; JAK3IN2; JAK3 IN 2; JAK3IN-2; JAK3-IN2
HS Tariff Code	2934.99.9001
Storage	Powder-20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month
Shipping Condition	Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Biological Activity

ln Vitro

JAK3-IN-6 (Compound 2) is a powerful JAK3 inhibitor with a concentration of 0.15 nM. In an enzymatic assay, it demonstrates a 4300-fold greater selectivity for JAK3 than JAK1, meaning that it is 67-fold (IL-2 vs. IL-6) or 140-fold (IL-2 vs. EPO or GMCSF) selective in cell reporter gene assays and >35-fold (IL-7 vs. IL-6 or GMCSF) in human PBMC assays. In order to ascertain whether there is an additive or synergistic effect of synergy, JAK3-IN-6 was cross-titrated with JAK1 selective inhibitor 3 (JAK1: 0.96 nM, JAK2: 14 nM, JAK3: >1500 nM, TYK2: 10 nM). This cross-titration was irreversible. shows that the predicted pSTAT5 inhibition levels based on the addition of JAK1 and JAK3 inhibition are very close to the measured effects of cross-titration of each compound, indicating that inhibition of JAK1 and JAK3 is Blocking STAT5 phosphorylation has additive but not synergistic effects. Inhibits the JAK1 and JAK3 enzymes that inhibit IL-7 signaling in CD3+, CD4+ PBMC. Furthermore, JAK1 or JAK3 inhibition on its own is adequate to totally block pSTAT5 [2].

References

[1]. ARYL SULFONOHYDRAZIDES. WO2017027400A1. [2]. Evaluation of JAK3 Biology in Autoimmune Disease Using a Highly Selective, Irreversible JAK3 Inhibitor. J Pharmacol Exp Ther. 2017 May;361(2):229-244.

Solubility Data

Solubility (In Vitro)

DMSO:10 mM Water:N/A Ethanol:N/A

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 2.17 mg/mL (6.19 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 21.7 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL. Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution. Solubility in Formulation 2: ≥ 2.17 mg/mL (6.19 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 21.7 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	2.8541 mL	14.2706 mL	28.5413 mL
	5 mM	0.5708 mL	2.8541 mL	5.7083 mL
	10 mM	0.2854 mL	1.4271 mL	2.8541 mL

*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.