Fuscoside (OPC21268; OPC-21268) is a vasopressin 1 receptor antagonist (IC50 = 0.4 μM.) potentially for the treatment of heart failure and hypertension.

Physicochemical Properties

Molecular Formula	C26H31N3O4
Molecular Weight	449.55
Exact Mass	449.231
Elemental Analysis	C, 69.47; H, 6.95; N, 9.35; O, 14.24
CAS #	131631-89-5
Related CAS #	131631-89-5
PubChem CID	114904
Appearance	White to off-white solid powder
Density	1.2±0.1 g/cm3
Boiling Point	772.5±60.0 °C at 760 mmHg
Flash Point	421.0±32.9 °C
Vapour Pressure	0.0±2.6 mmHg at 25°C
Index of Refraction	1.596
LogP	2.22
Hydrogen Bond Donor Count	1
Hydrogen Bond Acceptor Count	4
Rotatable Bond Count	7
Heavy Atom Count	33
Complexity	683
Defined Atom Stereocenter Count	0
SMILES	O=C(CC1)N(C2CCN(C(C3=CC=C(OCCCNC(C)=O)C=C3)=O)CC2)C4=C1C=CC=C4
InChi Key	KSNUCNRMDYJBKT-UHFFFAOYSA-N
InChi Code	InChI=1S/C26H31N3O4/c1-19(30)27-15-4-18-33-23-10-7-21(8-11-23)26(32)28-16-13-22(14-17-28)29-24-6-3-2-5-20(24)9-12-25(29)31/h2-3,5-8,10-11,22H,4,9,12-18H2,1H3,(H,27,30)
Chemical Name	N-[3-[4-[4-(2-oxo-3,4-dihydroquinolin-1-yl)piperidine-1-carbonyl]phenoxy]propyl]acetamide
Synonyms	OPC-21268; Fuscoside; OPC21268; OPC 21268
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

Targets	vasopressin V1 ( IC50 = 0.4 μM ); vasopressin V1 ( Ki = 0.14 μM )
ln Vitro	Fuscoside (OPC-21268) has an IC50 of 0.4 μM for VI receptors and 100 μM for V2 receptors, which means that it displaces 50% of specific AVP binding. Fuscoside (OPC-21268) has an inhibition constant (Ki) of 0.14 μM for V1 receptors[1].
ln Vivo	Fuscoside (OPC-21268) specifically and competitively inhibits pressor responses to AVP in vivo. In a dose- and time-dependent manner, oral administration of Fuscoside (OPC-21268) (10 mg/kg) inhibits the vasoconstriction induced by exogenous AVP, with an effect that lasts for more than 8 hours at 30 mg/kg[1]. Fuscoside (OPC-21268) works well to treat cold-induced vasogenic brain edema because it primarily provides protection where the blood-brain barrier is most likely to be broken down. Both hemispheres' brain water content is markedly decreased by fuscoside (OPC-21268) treatment at doses of 200 and 300 mg/kg. At dosages of 200 and 300 mg/kg, the injured hemispheres' swelling is also markedly decreased[2].
Animal Protocol	Rats: Fuscoside (OPC-21268) is injected subcutaneously (0.1, 0.3, or 1 mg/kg) into male Sprague-Dawley rats weighing 300–400 g. Two minutes prior to the injection of AVP (30 mU/kg i.v.), angiotensin II (0.3 μg/kg i.v.), and noradrenaline (3 μg/kg i.v.), fuscoside (OPC-21268) is administered[1].
References	[1]. OPC-21268, an orally effective, nonpeptide vasopressin V1 receptor antagonist. Science. 1991 Apr 26;252(5005):572-4. [2]. Treatment of brain edema with a nonpeptide arginine vasopressin V1 receptor antagonist OPC-21268 in rats. Neurosurgery. 1999 Jan;44(1):148-54.

Solubility Data

Solubility (In Vitro)

DMSO: ~50 mg/mL (~111.2 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 2.5 mg/mL (5.56 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 (5.56 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 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. Solubility in Formulation 3: ≥ 2.5 mg/mL (5.56 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	2.2244 mL	11.1222 mL	22.2445 mL
	5 mM	0.4449 mL	2.2244 mL	4.4489 mL
	10 mM	0.2224 mL	1.1122 mL	2.2244 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.