LDC000067 (also called LDC-000067; LDC-067) is a novel, potent, highly selective and ATP-competitive inhibitor of cyclin-dependent kinase (CDK9) with potential antineoplastic activity. With an IC50 of 44 nM, it suppresses CDK9. While CDK9 is a significant and highly effective therapeutic target for anticancer medications, the inhibitors that are currently on the market have limited therapeutic windows and/or low specificity. LDC000067 demonstrated a range of selectivity for CDK9 over other CDKs, from over 230-fold (versus CDK6 and CDK7) to 55-fold (versus CDK2). Additionally, LDC067 inhibited transcription in an ATP-competitive and dose-dependent manner. LDC000067 triggered apoptosis and the activation of the tumor suppressor protein p53 in whole cells. Additionally, LDC000067 specifically lowered short-lived mRNAs, such as MYC and MCL1, which encode regulators of apoptosis and proliferation.

Physicochemical Properties

Molecular Formula	C18H18N4O3S
Molecular Weight	370.43
Exact Mass	370.109
Elemental Analysis	C, 58.36; H, 4.90; N, 15.13; O, 12.96; S, 8.65
CAS #	1073485-20-7
Related CAS #	1073485-20-7
PubChem CID	25104564
Appearance	White to off-white solid powder
Density	1.4±0.1 g/cm3
Boiling Point	604.1±65.0 °C at 760 mmHg
Flash Point	319.2±34.3 °C
Vapour Pressure	0.0±1.7 mmHg at 25°C
Index of Refraction	1.646
LogP	2.11
Hydrogen Bond Donor Count	2
Hydrogen Bond Acceptor Count	7
Rotatable Bond Count	6
Heavy Atom Count	26
Complexity	539
Defined Atom Stereocenter Count	0
SMILES	S(C([H])([H])C1C([H])=C([H])C([H])=C(C=1[H])N([H])C1C([H])=C(C2=C([H])C([H])=C([H])C([H])=C2OC([H])([H])[H])N=C([H])N=1)(N([H])[H])(=O)=O
InChi Key	GGQCIOOSELPMBB-UHFFFAOYSA-N
InChi Code	InChI=1S/C18H18N4O3S/c1-25-17-8-3-2-7-15(17)16-10-18(21-12-20-16)22-14-6-4-5-13(9-14)11-26(19,23)24/h2-10,12H,11H2,1H3,(H2,19,23,24)(H,20,21,22)
Chemical Name	[3-[[6-(2-methoxyphenyl)pyrimidin-4-yl]amino]phenyl]methanesulfonamide
Synonyms	LDC067; LDC000067; LDC-000067; LDC-067; LDC 067; LDC 000067
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

Targets	CDK9- Cyclin T1 (IC50 = 44 nM); cdk2-cyclin A (IC50 = 2441 nM); cdk1-cyclin B1 (IC50 = 5513 nM); cdk4-cyclin D1 (IC50 = 9242 nM); GSK3A (IC50 = 1460 nM); HGK/MAP4K4 (IC50 = 820 nM); ABL2/ARG (IC50 = 3640 nM)
ln Vitro	LDC000067 is more selective for CDK9 than other CDKs, even more so than flavopiridol and DRB, which are recognized inhibitors of CDK9. In comparison to CDK2/1/4/6/7, LDC000067 showed 55/125/210/ >227/ >227-fold selectivity for CDK9. LDC000067 inhibits transcription in vitro in a dose-dependent and ATP-competitive manner. Gene expression profiling of LDC000067-treated cells shows a selective reduction of short-lived mRNAs, such as significant regulators of apoptosis and proliferation[1].
ln Vivo
Enzyme Assay	The LANCE Ultra KinaSelect Ser/Thr kit, which uses fluorescence resonance energy transfer (FRET) to calculate IC50 values, is used to measure the effectiveness of different CDK inhibitors. In summary, a CDK-cyclin pair phosphorylates a particular ULight MBP peptide substrate (final concentration of 50 nM) in a buffer containing ATP at the concentration of the Km values of each individual kinase (50 mM HEPES-KOH pH 7.5, 10 mM MgCl2, 1 mM EGTA, and 2 mM dithiothreitol) for one hour at room temperature. Phosphorylation is then identified by adding particular anti-phospho-antibodies (2 nM) labeled with Eu; these antibodies bind to the phosphopeptide and produce a FRET signal. After that, FRET signals are recorded[1].
Cell Assay	Specifically, LDC000067 exhibits selectivity for CDK9 over other CDKs ranging from 55-fold to over 230-fold, with an IC50 value of 44(10 nM). Its ATP-competitive kinase binding assay further demonstrates this selectivity. Apoptosis and the tumour suppressor protein p53 are two additional effects of LDC000067 on whole cells. Furthermore, gene expression profiling of cells treated with LDC000067 reveals a selective reduction of short-lived mRNAs, such as MCL1 and MYC, which encode regulators of proliferation and apoptosis.
Animal Protocol
References	[1]. Characterization of molecular and cellular functions of the cyclin-dependent kinase CDK9 using a novel specific inhibitor. Br J Pharmacol. 2014 Jan;171(1):55-68.

Solubility Data

Solubility (In Vitro)

DMSO: ~74 mg/mL (~199.8 mM) Water: <1 mg/mL Ethanol: <1 mg/mL

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 2.5 mg/mL (6.75 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 (6.75 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 (6.75 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	2.6996 mL	13.4978 mL	26.9957 mL
	5 mM	0.5399 mL	2.6996 mL	5.3991 mL
	10 mM	0.2700 mL	1.3498 mL	2.6996 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.