JANEX-1 (aslo known as WHI-P131) is a novel, potent and selective inhibitor of the Janus kinase 3 (JAK3) that selectively inhibits JAK3 with an IC50 of 78 µM and does not inhibit JAK1 and JAK2. It triggers apoptosis in human acute lymphoblastic leukemia (ALL) cells. Following i.v. administration, the terminal elimination half-life of WHI-P131 was 73.2 min in rats, 103.4 min in mice, and 45.0 min in monkeys. The i.v. administered WHI-P131 showed a very wide tissue distribution in mice. Following i.p. administration, WHI-P131 was rapidly absorbed in both rats and mice, and the time to reach the maximum plasma concentration (tmax) was 24.8 min in rats and 10.0 min in mice.

Physicochemical Properties

Molecular Formula	C16H15N3O3
Molecular Weight	297.31
Exact Mass	297.111
CAS #	202475-60-3
Related CAS #	202475-60-3
PubChem CID	3794
Appearance	White to gray solid powder
Density	1.3±0.1 g/cm3
Boiling Point	468.1±40.0 °C at 760 mmHg
Flash Point	236.9±27.3 °C
Vapour Pressure	0.0±1.2 mmHg at 25°C
Index of Refraction	1.689
LogP	2.73
Hydrogen Bond Donor Count	2
Hydrogen Bond Acceptor Count	6
Rotatable Bond Count	4
Heavy Atom Count	22
Complexity	350
Defined Atom Stereocenter Count	0
InChi Key	HOZUXBLMYUPGPZ-UHFFFAOYSA-N
InChi Code	InChI=1S/C16H15N3O3/c1-21-14-7-12-13(8-15(14)22-2)17-9-18-16(12)19-10-3-5-11(20)6-4-10/h3-9,20H,1-2H3,(H,17,18,19)
Chemical Name	4-[(6,7-dimethoxy-4-quinazolinyl)amino]-phenol
Synonyms	WHI-P131; WHI P-131; WHI P131; JANEX-1;JANEX 1;JANEX1
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	Even at concentrations as high as 350 μM, JANEX-1 (WHI-P131) exhibits strong inhibitory activity against JAK3 (IC50 is 78 μM), but not against JAK1 and JAK2, ZAP/SYK family tyrosine kinase SYK, TEC family tyrosine kinase BTK, SRC family tyrosine kinase Acid kinase LYN, or receptor family tyrosine kinase insulin receptor kinase. JAK3-expressing human leukemia cell lines NALM-6 and LC1;19 undergo apoptosis when exposed to JANEX-1, but not melanoma (M24-MET) or squamous cell carcinoma (SQ20B) cells. While JAK3-negative BT-20 breast cancer, M24-MET melanoma, or the SQ20B squamous carcinoma cell line are not inhibited by WHI-P131, it does so in a concentration-dependent way for the JAK3-positive leukemia cell lines DAUDI, RAMOS, LC1;19, NALM-6, MOLT-3, and HL-60. WHI-P131 has an EC50 of 24.4 μM in NALM-6 cells and 18.8 μM in DAUDI cells, which indicates that it suppresses colony formation in a concentration-dependent manner. WHI-P131 reduced several leukemia cell lines' in vitro colony formation by >99% at 100 μM. Conversely, in JAK3-negative M24-MET melanoma or SQ20B squamous carcinoma cell lines, JANEX-1 does not decrease clonogenicity [1].
ln Vivo	There are several dosages of JANEX-1 that can be used: 5 to 100 mg/kg. A dose-response curve with an effective dose 50 (ED50) value of 7.44 mg/kg was found by CPK activity evaluation. The levels of CPK and LDH were significantly lowered in mice given JANEX-1. Furthermore, JANEX-1-treated animals had a considerably smaller infarct size (30.16±2.79%) than I/R-operated mice (65.64±3.76%) [2]. The absorption of JANEX-1 (WHI-P131) occurs quickly; the maximum plasma JANEX-1 concentration (tmax) is reached in 24.7±1.7 minutes. With a 45.6±5.5 minute elimination half-life, JANEX-1 is removed quickly. The systemic exposure level (i.e., AUC) was the same as after intravenous injection, despite the fact that the estimated maximum plasma JANEX-1 concentration of 10.5 ± 0.8 μM is only half the Cmax after intraperitoneal injection of the same bolus dose. The bioavailability was 94.6%. The obtained results (17.1±2.2 μM?h vs. 18.1±1.2 μM?h) were quite similar [3].
Animal Protocol	Dissolved in DMSO in PBS; 20, 50 and 100 mg/kg/day; i.p. Female NOD mice
References	[1]. Structure-based design of specific inhibitors of Janus kinase 3 as apoptosis-inducing antileukemic agents. Clin Cancer Res. 1999 Jun;5(6):1569-82. [2]. Inhibition of Janus activated kinase-3 protects against myocardial ischemia and reperfusion injury in mice. Exp Mol Med. 2013 May 17;45:e23. [3]. In vivo toxicity and pharmacokinetic features of the janus kinase 3 inhibitor WHI-P131 [4-(4'hydroxyphenyl)-amino-6,7- dimethoxyquinazoline. Clin Cancer Res. 1999 Oct;5(10):2954-62. [4]. IL4 (interleukin 4) induces autophagy in B cells leading to exacerbated asthma. Autophagy. 2018;14(3):450-464.

Solubility Data

Solubility (In Vitro)

DMSO:≥ 5 mg/mL Water:<1mg/mL Ethanol:<1mg/mL

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 2.5 mg/mL (8.41 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 25.0 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: ≥ 2.5 mg/mL (8.41 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in 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 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly. Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution. Solubility in Formulation 3: ≥ 2.5 mg/mL (8.41 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 25.0 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	3.3635 mL	16.8175 mL	33.6349 mL
	5 mM	0.6727 mL	3.3635 mL	6.7270 mL
	10 mM	0.3363 mL	1.6817 mL	3.3635 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.