SKI-I is a potent and specific inhibitor of human sphingosine kinase (SK), inhibiting ST-hSK with IC50 of 1.2 μM. SKI-I also inhibits hERK2 (IC50=11 μM). SKI-I causes apoptosis in tumor cell lines.

Physicochemical Properties

Molecular Formula	C25H18N4O2
Molecular Weight	406.44
Exact Mass	406.143
CAS #	306301-68-8
PubChem CID	135515522
Appearance	Off-white to light yellow solid powder
LogP	5.243
Hydrogen Bond Donor Count	3
Hydrogen Bond Acceptor Count	4
Rotatable Bond Count	4
Heavy Atom Count	31
Complexity	655
Defined Atom Stereocenter Count	0
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 Note: This product requires protection from light (avoid light exposure) during transportation and storage.
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	IC50: 1.2 μM (ST-hSK); 11 μM (hERK2)[1]
ln Vitro	SKI-I (Compound I; 5 μg/mL) 99% inhibits SK activity[1]. T24 cells are induced to undergo apoptosis by SKI-I (10 μM; 24 h)[1]
References	[1]. Discovery and evaluation of inhibitors of human sphingosine kinase. Cancer Res. 2003 Sep 15;63(18):5962-9. [2]. Synthesis and bioactivity of sphingosine kinase inhibitors and their novel aspirinyl conjugated analogs. Eur J Med Chem. 2010 Sep;45(9):4149-56.

Solubility Data

Solubility (In Vitro)

DMSO : 100 mg/mL (246.04 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 2.5 mg/mL (6.15 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 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	2.4604 mL	12.3019 mL	24.6039 mL
	5 mM	0.4921 mL	2.4604 mL	4.9208 mL
	10 mM	0.2460 mL	1.2302 mL	2.4604 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.