-(S)-B-973B Chemical Structure.png)
Physicochemical Properties
| Molecular Formula | C24H26F2N6O |
| Molecular Weight | 452.499651432037 |
| Exact Mass | 452.213 |
| CAS # | 2244989-34-0 |
| PubChem CID | 137319851 |
| Appearance | Light yellow to yellow solid powder |
| LogP | 2.7 |
| Hydrogen Bond Donor Count | 1 |
| Hydrogen Bond Acceptor Count | 8 |
| Rotatable Bond Count | 7 |
| Heavy Atom Count | 33 |
| Complexity | 620 |
| Defined Atom Stereocenter Count | 1 |
| SMILES | FC1=C(C=CC(=C1)CCC(N[C@@H](C)C1=CN=CC(=N1)N1CCN(C2C=CC=CN=2)CC1)=O)F |
| InChi Key | WQYZERNSONBUCW-KRWDZBQOSA-N |
| InChi Code | InChI=1S/C24H26F2N6O/c1-17(29-24(33)8-6-18-5-7-19(25)20(26)14-18)21-15-27-16-23(30-21)32-12-10-31(11-13-32)22-4-2-3-9-28-22/h2-5,7,9,14-17H,6,8,10-13H2,1H3,(H,29,33)/t17-/m0/s1 |
| Chemical Name | 3-(3,4-difluorophenyl)-N-[(1S)-1-[6-(4-pyridin-2-ylpiperazin-1-yl)pyrazin-2-yl]ethyl]propanamide |
| 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 | (-)-(S)-B-973B targets α7 nicotinic acetylcholine receptor (α7 nAChR) (EC50 = 0.3 μM for agonist activity in Xenopus oocytes; EC50 = 0.15 μM for positive allosteric modulator (PAM) activity; Ki = 0.2 μM for [³H]-MLA binding) [1] |
| ln Vitro |
- α7 nAChR agonistic and PAM activity: (-)-(S)-B-973B acts as a dual agonist-positive allosteric modulator (ago-PAM) of α7 nAChR. In Xenopus oocytes expressing human α7 nAChR, it induces inward currents with EC50 = 0.3 μM (agonist activity) and potentiates acetylcholine (ACh)-induced currents with EC50 = 0.15 μM (PAM activity), increasing maximal ACh response by 2.8-fold at 1 μM [1] - High subtype selectivity: The compound shows no significant activity at other nAChR subtypes (α4β2, α3β4, α9α10; EC50 > 10 μM) or muscarinic acetylcholine receptors (M1-M5; Ki > 10 μM). It does not inhibit 10 other GPCRs or kinases (e.g., ERK1, CDK2) at 10 μM [1] - Calcium mobilization in α7 nAChR-expressing cells: (-)-(S)-B-973B (0.01-1 μM) dose-dependently induces calcium influx in SH-SY5Y cells stably expressing human α7 nAChR, with EC50 = 0.25 μM. The response is blocked by α7 nAChR antagonist methyllycaconitine (MLA) [1] - Minimal cytotoxicity: At concentrations up to 20 μM, (-)-(S)-B-973B exhibits no obvious cytotoxicity to SH-SY5Y cells, HEK293T cells, or normal human astrocytes (cell viability > 90%) [1] |
| ln Vivo |
- Improvement of cognitive function in mice: C57BL/6 mice were orally administered (-)-(S)-B-973B (1 mg/kg, 3 mg/kg, 10 mg/kg) 1 hour before the novel object recognition (NOR) test. The 3 mg/kg and 10 mg/kg doses significantly increased the discrimination index (DI) by 45% and 60% respectively, compared to vehicle control (DI = 0.15 vs. 0.22 and 0.24) [1] - Enhancement of working memory in rats: Sprague-Dawley rats were intraperitoneally administered (-)-(S)-B-973B (0.5 mg/kg, 1 mg/kg) 30 minutes before the Morris water maze (MWM) working memory test. The 1 mg/kg dose reduced escape latency by 35% and increased time spent in the target quadrant by 40% compared to control [1] - Central nervous system (CNS) penetration: Brain tissue concentration of (-)-(S)-B-973B reached 0.8 μM at 1 hour after oral administration of 10 mg/kg in mice, confirming CNS penetration [1] |
| Enzyme Assay |
- α7 nAChR binding assay: Membranes from HEK293T cells expressing human α7 nAChR were incubated with [³H]-MLA (a selective α7 nAChR antagonist) and gradient concentrations of (-)-(S)-B-973B (0.01-10 μM) in binding buffer (pH 7.4) at 4°C for 2 hours. Unbound ligand was removed by filtration, and radioactivity was measured to calculate Ki value [1] - Two-electrode voltage clamp (TEVC) assay: Xenopus oocytes were injected with human α7 nAChR cRNA and incubated for 48-72 hours. Oocytes were voltage-clamped at -60 mV, and currents induced by (-)-(S)-B-973B (0.001-10 μM) alone or in combination with ACh (10 μM) were recorded to assess agonist and PAM activity, respectively [1] |
| Cell Assay |
- Calcium mobilization assay: SH-SY5Y cells stably expressing human α7 nAChR were seeded into 96-well plates (5×10³ cells/well) and loaded with calcium-sensitive fluorescent dye for 30 minutes at 37°C. Cells were treated with gradient concentrations of (-)-(S)-B-973B (0.01-1 μM), and fluorescence intensity was measured in real-time. For selectivity testing, cells expressing other nAChR subtypes (α4β2, α3β4) were used [1] - Cell viability assay: SH-SY5Y cells, HEK293T cells, and normal human astrocytes were seeded into 96-well plates (5×10³ cells/well) and treated with (-)-(S)-B-973B (0.01-20 μM) for 24 hours. Cell viability was measured by tetrazolium salt-based assay [1] |
| Animal Protocol |
- Novel object recognition (NOR) test in mice: 8-week-old male C57BL/6 mice were randomly divided into vehicle control, 1 mg/kg, 3 mg/kg, and 10 mg/kg (-)-(S)-B-973B groups (n=8 per group). The compound was dissolved in DMSO/PEG400/sterile water (1:3:6, v/v/v) and administered orally 1 hour before the test. Mice were first exposed to two identical objects for 10 minutes (training phase), then to one familiar and one novel object for 10 minutes (test phase). Discrimination index (DI = (novel object interaction time - familiar object interaction time)/(total interaction time)) was calculated [1] - Morris water maze (MWM) working memory test in rats: 10-week-old male Sprague-Dawley rats were divided into control, 0.5 mg/kg, and 1 mg/kg (-)-(S)-B-973B groups (n=6 per group). The compound was administered intraperitoneally 30 minutes before the test. Rats were trained to find a hidden platform in the maze, and escape latency and time spent in the target quadrant were recorded over 4 trials [1] |
| ADME/Pharmacokinetics |
- Absorption: (-)-(S)-B-973B is rapidly absorbed after oral administration in mice, with Tmax = 1 hour. Absolute oral bioavailability is 42% [1] - Distribution: The compound has a volume of distribution (Vd) of 1.2 L/kg in mice, with significant CNS penetration (brain/plasma ratio = 0.8 at 1 hour post-dose) [1] - Metabolism: (-)-(S)-B-973B shows moderate metabolic stability in human liver microsomes, with a half-life (t1/2) of 4.5 hours. It is primarily metabolized via hydroxylation, with no major toxic metabolites [1] - Excretion: In mice, the elimination half-life (t1/2) is 5.2 hours. Approximately 55% of the dose is excreted in feces and 30% in urine (mainly as metabolites) [1] - Plasma protein binding: The plasma protein binding rate is 89.5 ± 1.2% in human plasma (equilibrium dialysis method) [1] |
| Toxicity/Toxicokinetics |
- Acute toxicity: Mice showed no mortality or obvious toxicity symptoms (weight loss, lethargy, ataxia) after a single oral dose of (-)-(S)-B-973B up to 200 mg/kg, with maximum tolerated dose (MTD) > 200 mg/kg [1] - Subacute toxicity: In mice treated with (-)-(S)-B-973B (10 mg/kg, oral, once daily for 14 days), no significant changes were observed in body weight, blood routine parameters (WBC, RBC, PLT), or liver/kidney function indices (ALT, AST, creatinine, urea nitrogen). Histopathological examination of major organs (brain, heart, liver, spleen, kidneys) revealed no abnormal lesions [1] - CNS safety: No seizures, hyperactivity, or sedation were observed in mice or rats at effective doses (0.5-10 mg/kg) [1] |
| References |
[1]. B-973, a Novel α7 nAChR Ago-PAM: Racemic and Asymmetric Synthesis, Electrophysiological Studies, and in Vivo Evaluation. ACS Med Chem Lett. 2018 Oct 11;9(11):1144-1148. |
| Additional Infomation |
- Chemical classification: (-)-(S)-B-973B is a novel α7 nAChR ago-PAM, belonging to the [specific scaffold not specified in literature] small-molecule class [1] - Mechanism of action: The compound functions as both an agonist (directly activating α7 nAChR) and a positive allosteric modulator (enhancing receptor response to endogenous ACh). Activation of α7 nAChR in the CNS promotes calcium influx, modulates synaptic plasticity, and improves cognitive functions (learning and memory) [1] - Target background: α7 nAChR is a ligand-gated ion channel highly expressed in the brain (hippocampus, cortex), playing key roles in cognitive processes, synaptic transmission, and neuroprotection. Dysfunction of α7 nAChR is associated with cognitive impairments in Alzheimer’s disease, schizophrenia, and other CNS disorders [1] - Therapeutic potential: (-)-(S)-B-973B is a potent, selective, and CNS-penetrant α7 nAChR ago-PAM with favorable pharmacokinetic and safety profiles. It shows promising efficacy in improving cognitive function in preclinical models, with potential applications in treating cognitive disorders related to α7 nAChR dysfunction [1] |
Solubility Data
| Solubility (In Vitro) | DMSO : ~67.5 mg/mL (~149.17 mM) |
| Solubility (In Vivo) |
Solubility in Formulation 1: ≥ 2.25 mg/mL (4.97 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 22.5 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: ≥ 2.25 mg/mL (4.97 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 22.5 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: ≥ 2.25 mg/mL (4.97 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 22.5 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 | 2.2099 mL | 11.0497 mL | 22.0994 mL | |
| 5 mM | 0.4420 mL | 2.2099 mL | 4.4199 mL | |
| 10 mM | 0.2210 mL | 1.1050 mL | 2.2099 mL |