KL044, a stabilizer of the clock protein cryptochrome (CRY), is a potent chemical probe with pEC50 of 7.32 that can extend the circadian period and inhibit Per2 activity.

Physicochemical Properties

Molecular Formula	C21H14CLN3O
Molecular Weight	359.81
Exact Mass	359.082
CAS #	1801856-93-8
PubChem CID	91827381
Appearance	Off-white to gray solid powder
Density	1.3±0.1 g/cm3
Boiling Point	567.6±60.0 °C at 760 mmHg
Flash Point	297.1±32.9 °C
Vapour Pressure	0.0±1.6 mmHg at 25°C
Index of Refraction	1.675
LogP	6.46
Hydrogen Bond Donor Count	1
Hydrogen Bond Acceptor Count	2
Rotatable Bond Count	3
Heavy Atom Count	26
Complexity	551
Defined Atom Stereocenter Count	0
InChi Key	ZDAKKNHUWVTCRS-UHFFFAOYSA-N
InChi Code	InChI=1S/C21H14ClN3O/c22-17-9-5-6-14(12-23)21(17)24-20(26)13-25-18-10-3-1-7-15(18)16-8-2-4-11-19(16)25/h1-11H,13H2,(H,24,26)
Chemical Name	2-carbazol-9-yl-N-(2-chloro-6-cyanophenyl)acetamide
Synonyms	KL-044; KL 044; KL044
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	In the HEK293 stable cell line, KL044 (0-3.7 μM; 8 h) efficiently stabilizes the CRY1-LUC fusion protein without compromising the stability of LUC [1].
References	[1]. Development of Small-Molecule Cryptochrome Stabilizer Derivatives as Modulators of the Circadian Clock. ChemMedChem. 2015 Sep;10(9):1489-97.

Solubility Data

Solubility (In Vitro)

DMSO : ~100 mg/mL (~277.92 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 2.5 mg/mL (6.95 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	2.7792 mL	13.8962 mL	27.7924 mL
	5 mM	0.5558 mL	2.7792 mL	5.5585 mL
	10 mM	0.2779 mL	1.3896 mL	2.7792 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.