K03861 (K0 3861; AUZ-454; K-03861; AUZ 454), an aminopyrimidine-phenyl urea analog, is novel and potent type II cyclin-dependent kinase-CDK2 inhibitor with potential anticancer activity. In that order, its Kd values are 50 nM, 18.6 nM, 15.4 nM, and 9.7 nM for CDK2(WT), CDK2(C118L), CDK2(A144C), and CDK2(C118L/A144C). A canonical type II binding mode was revealed by the cocrystal structure of CDK2 in complex with K03861. K03861 works by interfering with cyclin binding.

Physicochemical Properties

Molecular Formula	C24H26F3N7O2
Molecular Weight	501.50
Exact Mass	501.21
Elemental Analysis	C, 57.48; H, 5.23; F, 11.36; N, 19.55; O, 6.38
CAS #	853299-07-7
Related CAS #	853299-07-7
PubChem CID	11260561
Appearance	White to off-white solid powder
Density	1.4±0.1 g/cm3
Index of Refraction	1.642
LogP	3.41
Hydrogen Bond Donor Count	3
Hydrogen Bond Acceptor Count	10
Rotatable Bond Count	6
Heavy Atom Count	36
Complexity	700
Defined Atom Stereocenter Count	0
SMILES	O=C(NC1C=C(C(F)(F)F)C(CN2CCN(C)CC2)=CC=1)NC1C=CC(OC2C=CN=C(N)N=2)=CC=1
InChi Key	PWDLXPJQFNVTNL-UHFFFAOYSA-N
InChi Code	InChI=1S/C24H26F3N7O2/c1-33-10-12-34(13-11-33)15-16-2-3-18(14-20(16)24(25,26)27)31-23(35)30-17-4-6-19(7-5-17)36-21-8-9-29-22(28)32-21/h2-9,14H,10-13,15H2,1H3,(H2,28,29,32)(H2,30,31,35)
Chemical Name	1-[4-(2-aminopyrimidin-4-yl)oxyphenyl]-3-[4-[(4-methylpiperazin-1-yl)methyl]-3-(trifluoromethyl)phenyl]urea
Synonyms	K03861; AUZ454; K-03861; AUZ 454;K 03861; AUZ-454
HS Tariff Code	2934.99.03.00
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

Targets	CDK2(C118L/A144C) (Kd = 9.7 nM); CDK2(A144C) (Kd = 15.4 nM); CDK2(C118L) (Kd = 18.6 nM); CDK2(WT) (Kd = 50 nM); CDK2(C118L/A144C-Cyclin B) (Kd = 134.1 nM)
ln Vitro	K03861 competes with activating cyclin binding to inhibit CDK2 activity.[1]
ln Vivo
Enzyme Assay	K03861 is an inhibitor of type II CDK2 with a Kd of 8.2 nM. AUZ 454 (K03861) competes with activating cyclin binding to inhibit CDK2 activity.
Cell Assay	Cell Line: Caki-1 and ACHN cells Concentration: 10 μM; 20 μM Incubation Time: 1, 2, 3, and 4 days Result: Inhibited cell proliferation in a CDK2-dependent manner.
Animal Protocol
References	[1]. Type II Inhibitors Targeting CDK2. ACS Chem Biol. 2015 Sep 18;10(9):2116-25. [2]. Wilms' tumor 1-associating protein promotes renal cell carcinoma proliferation by regulating CDK2 mRNA stability.J Exp Clin Cancer Res. 2018 Feb 27;37(1):40.

Solubility Data

Solubility (In Vitro)

DMSO: ~100 mg/mL (~199.4 mM) Water: <1 mg/mL Ethanol: ~15 mg/mL (~29.9 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 2.08 mg/mL (4.15 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 20.8 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: ≥ 2.08 mg/mL (4.15 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 20.8 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: ≥ 2.08 mg/mL (4.15 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 20.8 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	1.9940 mL	9.9701 mL	19.9402 mL
	5 mM	0.3988 mL	1.9940 mL	3.9880 mL
	10 mM	0.1994 mL	0.9970 mL	1.9940 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.