CB-1 (IC50 = 22 nM ; Ki = 7.8 nM)

Though their clinical application has been hindered by serious side effects, cannabinoid receptor 1 (CB1R) antagonists seem to be promising medications for the treatment of obesity. Ibipinabant is a new, potent [Ki (CB1)=7.8 nM] and selective [Ki (CB2)=7.943 nM] CB1 antagonist [pA2 for arachidonic acid release in CHO cells=9.9] with in vitro pharmacological characteristics similar to rimonabant including inverse agonism and brain penetrance[3].

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Analogs of SLV-319 (Ibipinibant), a CB1 receptor inverse agonist, were synthesized with functionality intended to limit brain exposure while maintaining the receptor affinity and selectivity of the parent compound. Structure activity relationships of this series, and pharmacology of two lead compounds, 16 (JD-5006) and 23 (JD-5037) showing little brain presence as indicated by tissue distribution and receptor occupancy studies, are described. Effects with one of these compounds on plasma triglyceride levels, liver weight and enzymes, glucose tolerance and insulin sensitivity support the approach that blockade of peripheral CB(1) receptors is sufficient to produce many of the beneficial metabolic effects of globally active CB(1) blockers. Thus, PR CB(1) inverse agonists may indeed represent a safer alternative to highly brain-penetrant agents for the treatment of metabolic disorders, including diabetes, liver diseases, dyslipidemias, and obesity.[1]

On days 17, 28, and 38, (±)-Ibipinabant ((±)-SLV319) (3 mg/kg) significantly lowers unfasted glucose compared to rimonabant at the same dose. In ZDF rats, long-term administration of (±)-Ibipinabant ((±)-SLV319) substantially slows down the development of diabetes, reducing the rate of blood glucose and HbA1c increases over time. Additionally, if administered 6–8 weeks after birth, ibipinabant lessens the hyperinsulinemia that is visible and lessens the sharp decline in insulin levels that occurs 1-2 weeks later[3].

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In diet-induced obesity (DIO) mice, SLV319 (3 mg/kg/day; po for 28 d) decreases food intake, body weight, and hormonal/metabolic abnormalities[2]. SLV319 (3 mg/kg/day, po for 28 days) counteracts the rise in adipose tissue leptin mRNA that is brought on by a high fat diet[2]. In a rat model of progressive β-cell failure, SLV319 (3–10 mg/kg; daily oral gavage for 56 days) attenuates β-cell loss and has weight loss-independent antidiabetic effects[3]. With an ED50 of 5.5 and 3 mg/kg, respectively, SLV319 (oral dosing) counteracts CB agonist (CP55940)-induced hypotension in rats and hypothermia in mice[1].

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At the end of the study, vehicle-treated ZDF rats were severely hyperglycaemic and showed signs of β-cell decline, including dramatic reductions in unfasted insulin levels. Ibipinanbant (10 mg/kg) reduced the following relative to vehicle controls: fasting glucose (-61%), glucose excursion area under the curve (AUC) in an oral glucose tolerance test (OGTT, -44%) and HbA1c (-50%). Furthermore, non-fasting insulin, islet area and islet insulin content were all increased (71, 40 and 76%, respectively) relative to vehicle controls by the end of the study. All of these effects were similar to those of rimonabant and rosiglitazone, where ibipinabant was slightly more effective than rimonabant at the lowest dose and somewhat less effective than rosiglitazone at all doses. These antidiabetic effects appear independent of weight loss because none of the parameters above were consistently improved by the comparable weight loss induced by food restriction. Conclusions: Ibipinabant may have weight loss-independent antidiabetic effects and may have the potential to attenuate β-cell loss in a model of progressive β-cell dysfunction [3].

Receptor Binding Assays.[2]
1. CB1 Assay. CB1 receptor affinities were determined using membrane preparations of Chinese hamster ovary (CHO) cells in which the human cannabinoid CB1 receptor is stably transfected in conjunction with [3H]CP-55,940 as radioligand. After incubation of a freshly prepared cell membrane preparation with the [3H]-radioligand, with or without addition of test compound, separation of bound and free ligand was performed by filtration over glassfiber filters. Radioactivity on the filter was measured by liquid scintillation counting. The IC50 values from at least three independent measurements were combined and converted to Ki values using the assumptions of Cheng and Prusoff. [2]

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2. CB2 Assay. [2]
CB2 receptor affinities were determined using membrane preparations of Chinese hamster ovary (CHO) cells in which the human cannabinoid CB2 receptor is stably transfected20 in conjunction with [3H]CP-55,940 as radioligand. After incubation of a freshly prepared cell membrane preparation with the [3H]-radioligand, with or without addition of test compound, separation of bound and free ligand was performed by filtration over glassfiber filters. Radioactivity on the filter was measured by liquid scintillation counting. The IC50 values from at least two independent measurements were combined and converted to Ki values using the assumptions of Cheng and Prusoff.[2]

In Vitro Pharmacology. Measurement of Arachidonic Acid Release. CB1 receptor antagonism21 was assessed with the human CB1 receptor cloned in Chinese hamster ovary (CHO) cells. CHO cells were grown in a Dulbecco's modified Eagle's medium (DMEM) culture medium, supplemented with 10% heat-inactivated fetal calf serum. Medium was aspirated and replaced by DMEM, without fetal calf serum, but containing [3H]-arachidonic acid and incubated overnight in a cell culture stove (5% CO2/95% air; 37 °C; water-saturated atmosphere). During this period [3H]-arachidonic acid was incorporated in membrane phospholipids. On the test day, medium was aspirated and cells were washed three times using 0.5 mL of DMEM, containing 0.2% bovine serum albumin (BSA). Stimulation of the CB1 receptor by WIN 55,212-2 led to activation of PLA2 followed by release21 of [3H]-arachidonic acid into the medium. This WIN 55,212-2-induced release was concentration dependently antagonized by CB1 receptor antagonists. The CB1 antagonistic potencies of the test compounds were expressed as pA2 values[2].

Rats: SLV319, rimonabant, and rosiglitazone are suspended in a vehicle consisting of 70% water, 10% ethanol, 10% cremophor, and 10% dimethylacetamide. Oral gavage is used to administer drugs at 09:00 hours daily in a volume of 2 mL/kg body weight. These are the treatment groups: (i) Ad libitum access to food (vehicle); (ii) Restricted access to food (20% less than the average food intake of the ad libitum vehicle-treated group for the first three days of the study, then 10% less than the average food intake of the ad libitum vehicle-treated group for the remainder of the study) (restricted); (iii) Rosiglitazone (4 mg/kg); (iv) Rimonabant (3 mg/kg) (RIM 3 mg/kg); (v) Rimonabant (10 mg/kg) (RIM 10 mg/kg); (vi) (±)-Ibipinabant ((±)-SLV319) (3 mg/kg) (IBI 3 mg/kg); and (vii) Ibipinabant (10 mg/kg) (IBI 10 mg/kg). For its capacity to postpone β-cell decline, rosiglitazone is employed as a positive control, and rimonabant is employed as a positive control for CB1 antagonism[3].

[1]. JD-5006 and JD-5037: peripherally restricted (PR) cannabinoid-1 receptor blockers related to SLV-319 (Ibipinabant) as metabolic disorder therapeutics devoid of CNS liabilities. Bioorg Med Chem Lett. 2012 Oct 1;22(19):6173-80.

[2]. Synthesis, biological properties, and molecular modeling investigations of novel 3,4-diarylpyrazolines as potent and selective CB(1) cannabinoid receptor antagonists. J Med Chem. 2004 Jan 29;47(3):627-43.

[3]. Ibipinabant attenuates β-cell loss in male Zucker diabetic fatty rats independently of its effects on body weight. Diabetes Obes Metab. 2012 Jun;14(6):555-64.

Analogs of SLV-319 (Ibipinibant), a CB1 receptor inverse agonist, were synthesized with functionality intended to limit brain exposure while maintaining the receptor affinity and selectivity of the parent compound. Structure activity relationships of this series, and pharmacology of two lead compounds, 16 (JD-5006) and 23 (JD-5037) showing little brain presence as indicated by tissue distribution and receptor occupancy studies, are described. Effects with one of these compounds on plasma triglyceride levels, liver weight and enzymes, glucose tolerance and insulin sensitivity support the approach that blockade of peripheral CB(1) receptors is sufficient to produce many of the beneficial metabolic effects of globally active CB(1) blockers. Thus, PR CB(1) inverse agonists may indeed represent a safer alternative to highly brain-penetrant agents for the treatment of metabolic disorders, including diabetes, liver diseases, dyslipidemias, and obesity.[1]

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A series of novel 3,4-diarylpyrazolines was synthesized and evaluated in cannabinoid (hCB(1) and hCB(2)) receptor assays. The 3,4-diarylpyrazolines elicited potent in vitro CB(1) antagonistic activities and in general exhibited high CB(1) vs CB(2) receptor subtype selectivities. Some key representatives showed potent pharmacological in vivo activities after oral dosing in both a CB agonist-induced blood pressure model and a CB agonist-induced hypothermia model. Chiral separation of racemic 67, followed by crystallization and an X-ray diffraction study, elucidated the absolute configuration of the eutomer 80 (SLV319) at its C(4) position as 4S. Bioanalytical studies revealed a high CNS-plasma ratio for the development candidate 80. Molecular modeling studies showed a relatively close three-dimensional structural overlap between 80 and the known CB(1) receptor antagonist rimonabant (SR141716A). Further analysis of the X-ray diffraction data of 80 revealed the presence of an intramolecular hydrogen bond that was confirmed by computational methods. Computational models and X-ray diffraction data indicated a different intramolecular hydrogen bonding pattern in the in vivo inactive compound 6. In addition, X-ray diffraction studies of 6 revealed a tighter intermolecular packing than 80, which also may contribute to its poorer absorption in vivo. Replacement of the amidine -NH(2) moiety with a -NHCH(3) group proved to be the key change for gaining oral biovailability in this series of compounds leading to the identification of 80.[2]

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Aim: To test the antidiabetic efficacy of ibipinabant, this new cannabinoid receptor 1 (CB1) antagonist was compared with food-restriction-induced weight loss, rosiglitazone (4 mg/kg) and rimonabant (3 and 10 mg/kg), using parameters of glycaemic control in male Zucker diabetic fatty (ZDF) rats.[3]
Methods: Body weight, food and water intake, fasted and non-fasted glucose and insulin, glucose tolerance and glycosylated haemoglobin (HbA1c) were all assessed over the course of the 9-week study. Pancreatic insulin content and islet area were also evaluated.[3]
Results: At the end of the study, vehicle-treated ZDF rats were severely hyperglycaemic and showed signs of β-cell decline, including dramatic reductions in unfasted insulin levels. Ibipinanbant (10 mg/kg) reduced the following relative to vehicle controls: fasting glucose (-61%), glucose excursion area under the curve (AUC) in an oral glucose tolerance test (OGTT, -44%) and HbA1c (-50%). Furthermore, non-fasting insulin, islet area and islet insulin content were all increased (71, 40 and 76%, respectively) relative to vehicle controls by the end of the study. All of these effects were similar to those of rimonabant and rosiglitazone, where ibipinabant was slightly more effective than rimonabant at the lowest dose and somewhat less effective than rosiglitazone at all doses. These antidiabetic effects appear independent of weight loss because none of the parameters above were consistently improved by the comparable weight loss induced by food restriction.[3]
Conclusions: Ibipinabant may have weight loss-independent antidiabetic effects and may have the potential to attenuate β-cell loss in a model of progressive β-cell dysfunction.[3]

C23H20CL2N4O2S

487.4015

486.068

C, 56.68; H, 4.14; Cl, 14.55; N, 11.50; O, 6.57; S, 6.58

362519-49-1

464213-10-3 (S-isomer)； 656827-86-0 (R-isomer); 362519-49-1 (racemate)

11179267

White to off-white solid powder

1.4±0.1 g/cm3

623.2±65.0 °C at 760 mmHg

330.7±34.3 °C

0.0±1.8 mmHg at 25°C

1.663

4.67

1

4

6

32

791

0

C/N=C(N1N=C(C2=CC=C(Cl)C=C2)C(C3=CC=CC=C3)C1)\NS(=O)(C4=CC=C(Cl)C=C4)=O

AXJQVVLKUYCICH-UHFFFAOYSA-N

InChI=1S/C23H20Cl2N4O2S/c1-26-23(28-32(30,31)20-13-11-19(25)12-14-20)29-15-21(16-5-3-2-4-6-16)22(27-29)17-7-9-18(24)10-8-17/h2-14,21H,15H2,1H3,(H,26,28)

5-(4-chlorophenyl)-N-(4-chlorophenyl)sulfonyl-N'-methyl-4-phenyl-3,4-dihydropyrazole-2-carboximidamide

JD5001; JD-5001; JD 5001; (±)-SLV-319; (±)-SLV 319; SLV319; (±)-BMS-646256; (±)-BMS646256; (±)-BMS 646256; (±)-Ibipinabant; 3-(4-Chlorophenyl)-N-((4-chlorophenyl)sulfonyl)-N'-methyl-4-phenyl-4,5-dihydro-1H-pyrazole-1-carboximidamide; ((plusmn))-SLV319; (+/-)-Ibipinabant; ( inverted exclamation markA)-SLV319; ( inverted exclamation markA)-Ibipinabant; CHEMBL158784;

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: Please store this product in a sealed and protected environment (e.g. under nitrogen), avoid exposure to moisture.

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO: ≥ 31 mg/mL (~63.6 mM)

Solubility in Formulation 1: ≥ 2.5 mg/mL (5.13 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.

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Solubility in Formulation 2: ≥ 2.5 mg/mL (5.13 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.

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 (Please use freshly prepared in vivo formulations for optimal results.)