Orexin receptor antagonist 2 is a potent orexin receptor antagonist (inhibitor) with pKi of 7.69 and 9.78 respectively. Orexin receptor antagonist 2 has potential in insomnia research.

Physicochemical Properties

Molecular Formula	C25H31N5O2
Molecular Weight	433.54594540596
Exact Mass	433.247
CAS #	1457940-75-8
PubChem CID	72704097
Appearance	Off-white to light yellow solid powder
LogP	3.3
Hydrogen Bond Donor Count	1
Hydrogen Bond Acceptor Count	5
Rotatable Bond Count	4
Heavy Atom Count	32
Complexity	657
Defined Atom Stereocenter Count	0
SMILES	O=C1C2(CCN(C3N=C(C)C=C(C)N=3)CC2)CCCN1CC1=CNC2C=CC(=CC1=2)OC
InChi Key	GKTSTVGKOKZFKP-UHFFFAOYSA-N
InChi Code	InChI=1S/C25H31N5O2/c1-17-13-18(2)28-24(27-17)29-11-8-25(9-12-29)7-4-10-30(23(25)31)16-19-15-26-22-6-5-20(32-3)14-21(19)22/h5-6,13-15,26H,4,7-12,16H2,1-3H3
Chemical Name	9-(4,6-dimethylpyrimidin-2-yl)-2-[(5-methoxy-1H-indol-3-yl)methyl]-2,9-diazaspiro[5.5]undecan-1-one
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]. Identification of a novel series of orexin receptor antagonists with a distinct effect on sleep architecture for the treatment of insomnia. J Med Chem. 2013;56(19):7590-7607.

Solubility Data

Solubility (In Vitro)

DMSO: 62.5 mg/mL (144.16 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 2.08 mg/mL (4.80 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 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 (4.80 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	2.3065 mL	11.5327 mL	23.0654 mL
	5 mM	0.4613 mL	2.3065 mL	4.6131 mL
	10 mM	0.2307 mL	1.1533 mL	2.3065 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.