Foslevcromakalim (QLS-101) is an ATP-sensitive potassium channel opener. Foslevcromakalim is a precursor for intraocular hypotensive effects.

Physicochemical Properties

Molecular Formula	C16H19N2O6P
Molecular Weight	366.305625200272
Exact Mass	366.098
CAS #	1802655-72-6
PubChem CID	91826794
Appearance	Off-white to light yellow solid powder
LogP	-0.3
Hydrogen Bond Donor Count	2
Hydrogen Bond Acceptor Count	7
Rotatable Bond Count	3
Heavy Atom Count	25
Complexity	638
Defined Atom Stereocenter Count	2
SMILES	CC1([C@H]([C@@H](C2=C(O1)C=CC(=C2)C#N)N3CCCC3=O)OP(=O)(O)O)C
InChi Key	JRUHOGHWZXTUMZ-CABCVRRESA-N
InChi Code	InChI=1S/C16H19N2O6P/c1-16(2)15(24-25(20,21)22)14(18-7-3-4-13(18)19)11-8-10(9-17)5-6-12(11)23-16/h5-6,8,14-15H,3-4,7H2,1-2H3,(H2,20,21,22)/t14-,15+/m1/s1
Chemical Name	[(3S,4R)-6-cyano-2,2-dimethyl-4-(2-oxopyrrolidin-1-yl)-3,4-dihydrochromen-3-yl] dihydrogen phosphate
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]. Pervan-Steel CL, et al. Ocular Hypotensive Properties and Biochemical Profile of QLS-101, a Novel ATP-Sensitive Potassium (KATP) Channel Opening Prodrug. Invest Ophthalmol Vis Sci. 2022 Apr 1;63(4):26. [2]. WHO Drug Information-World Health Organization (WHO).

Additional Infomation

Foslevcromakalim is an ophthalmic solution containing a prodrug of levcromakalim, a modulator of the adenosine triphosphate (ATP)-sensitive potassium (KATP) channel, with potential vasodilating and episcleral venous pressure (EVP)-lowering activities. Upon application into the eye, foslevcromakalim is converted to levcromakalim, which dilates blood vessels by opening the KATP channel. This lowers both EVP and elevated intraocular pressure (IOP).

Solubility Data

Solubility (In Vitro)

DMSO: 60 mg/mL (163.80 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 3 mg/mL (8.19 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 30.0 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: ≥ 3 mg/mL (8.19 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 30.0 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: ≥ 3 mg/mL (8.19 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 30.0 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	2.7299 mL	13.6496 mL	27.2993 mL
	5 mM	0.5460 mL	2.7299 mL	5.4599 mL
	10 mM	0.2730 mL	1.3650 mL	2.7299 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.