SKI V is a noncompetitive, potent inhibitor of nonlipid sphingosine kinase (SPHK; SK) with IC50 of 2 μM for GST-hSK. SKI V effectively inhibits PI3K, with IC50 of 6 μM for hPI3k. SKI V reduces the formation of the mitotic second messenger sphingosine-1-phosphate (S1P). SKI V causes apoptosis and has anti-tumor activity.

Physicochemical Properties

Molecular Formula	C15H10O4
Molecular Weight	254.2375
Exact Mass	254.057
CAS #	24418-86-8
PubChem CID	5793932
Appearance	Light yellow to yellow solid powder
LogP	2.9
Hydrogen Bond Donor Count	2
Hydrogen Bond Acceptor Count	4
Rotatable Bond Count	1
Heavy Atom Count	19
Complexity	390
Defined Atom Stereocenter Count	0
SMILES	O1C(=C([H])C2C([H])=C([H])C(=C(C=2[H])O[H])O[H])C(C2=C([H])C([H])=C([H])C([H])=C12)=O
InChi Key	HCBULGQMULJTCM-ZSOIEALJSA-N
InChi Code	InChI=1S/C15H10O4/c16-11-6-5-9(7-12(11)17)8-14-15(18)10-3-1-2-4-13(10)19-14/h1-8,16-17H/b14-8-
Chemical Name	(2Z)-2-[(3,4-dihydroxyphenyl)methylidene]-1-benzofuran-3-one
Synonyms	SKI V; SKI-V
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	SKI V does not inhibit PKC-α and has weak activity against ERK2 (IC50 for hERK2 is 80 μM)[1]. SKI V (10 μM; for 24 hours) causes apoptosis and suppresses the growth of cancer cells [1]. SKI V decreased the levels of phospho-Akt and phospho-MEK (0.2, 1, 5 μM; 1 hour pretreatment). After 16 hours of serum starvation, near-confluent JC cell cultures received a 1-hour SKI V pretreatment [2]. SKI V suppresses the growth of tumor cells and sphingosine kinase (SK) at an IC50 of approximately 2 μM [1]. In MDA-MB-231 cells, SKI V (20 μg/ml) suppresses both endogenous and purified SK [1]. In JC cells, SKI V (0.2, 1, 5 μM) suppresses the production of intracellular S1P in a dose-dependent manner [2].
ln Vivo	In comparison with control rats, SKI V (75 mg/kg; i.p.; days 1, 5, 9, 15) significantly slowed tumor growth (reduction of >50% on day 18) [1].
Cell Assay	Cell proliferation assay[1] Cell Types: T24 tumor cell Tested Concentrations: 10 μM Incubation Duration: 24 hrs (hours) Experimental Results: Inhibition of cancer cell proliferation. Apoptosis analysis[1] Cell Types: T24 tumor cells Tested Concentrations: 10 μM Incubation Duration: 24 hrs (hours) Experimental Results: Induction of apoptosis. Western Blot Analysis[2] Cell Types: JC Cell Tested Concentrations: 0.2, 1, 5 μM Incubation Duration: 1 hour pretreatment Experimental Results: diminished levels of phospho-Akt and phospho-MEK.
Animal Protocol	Animal/Disease Models: 6-8 weeks old BALB/c female mice, JC breast cancer cells [1] Doses: 75 mg/kg Route of Administration: IP; results on days 1, 5, 9, and 15: compared with control animals Tumor growth was Dramatically diminished (>50% reduction on day 18) compared with tumor growth.
References	[1]. Discovery and evaluation of inhibitors of human sphingosine kinase. Cancer Res. 2003 Sep 15;63(18):5962-9. [2]. Antitumor activity of sphingosine kinase inhibitors. J Pharmacol Exp Ther. 2006 Aug;318(2):596-603.
Additional Infomation	3',4'-dihydroxyaurone is a hydroxyaurone that is aurone which is substituted by hydroxy groups at the 3' and 4' positions; major species at pH 7.3. It shows inhibitory activity against several isoforms of the histone deacetylase complex (HDAC). It has a role as an EC 3.5.1.98 (histone deacetylase) inhibitor. It is a hydroxyaurone and a member of catechols. It is functionally related to a 2',3,4-trihydroxy-trans-chalcone.

Solubility Data

Solubility (In Vitro)

DMSO : ~50 mg/mL (~196.66 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 2.5 mg/mL (9.83 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 (9.83 mM) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), suspension solution; with ultrasonication. 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.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	3.9333 mL	19.6665 mL	39.3329 mL
	5 mM	0.7867 mL	3.9333 mL	7.8666 mL
	10 mM	0.3933 mL	1.9666 mL	3.9333 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.