SEC inhibitor KL-1 (KL-1) is a peptidomimetic lead compound and a potent and specific SEC inhibitor that causes Pol II to detach from the promoter-proximal region by disrupting the interaction between the SEC scaffolding proteins AFF4 and P-TEFb. Release from pause sites is impaired and the average rate of progressive transcription elongation is reduced. SEC inhibitor KL-1 inhibits AFF4-CCNT1 interaction in a dose-dependent fashion with Ki of 3.48 μM.

Physicochemical Properties

Molecular Formula	C18H16CLNO4
Molecular Weight	345.776944160461
Exact Mass	345.076
CAS #	900308-84-1
PubChem CID	46248683
Appearance	Light yellow to yellow solid powder
LogP	4
Hydrogen Bond Donor Count	2
Hydrogen Bond Acceptor Count	4
Rotatable Bond Count	5
Heavy Atom Count	24
Complexity	493
Defined Atom Stereocenter Count	0
SMILES	CC1=C(C=C(C=C1)Cl)NC(=O)C(=O)/C=C(/C2=CC(=CC=C2)OC)\O
InChi Key	ARTVILCEXNCVIN-YBEGLDIGSA-N
InChi Code	InChI=1S/C18H16ClNO4/c1-11-6-7-13(19)9-15(11)20-18(23)17(22)10-16(21)12-4-3-5-14(8-12)24-2/h3-10,21H,1-2H3,(H,20,23)/b16-10-
Chemical Name	(Z)-N-(5-chloro-2-methylphenyl)-4-hydroxy-4-(3-methoxyphenyl)-2-oxobut-3-enamide
Synonyms	KL-1; KL 1; KL1
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

References

[1]. Targeting Processive Transcription Elongation via SEC Disruption for MYC-Induced CancerTherapy. Cell. 2018 Oct 18;175(3):766-779.

Solubility Data

Solubility (In Vitro)

DMSO : ~41.67 mg/mL (~120.51 mM)

Solubility (In Vivo)

Solubility in Formulation 1: 2.08 mg/mL (6.02 mM) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), suspension solution; with sonication. 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 (6.02 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	2.8920 mL	14.4601 mL	28.9201 mL
	5 mM	0.5784 mL	2.8920 mL	5.7840 mL
	10 mM	0.2892 mL	1.4460 mL	2.8920 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.