| Field | Specification |
|---|---|
| Target | |
| Alternative names | R 50547 |
| CAS no. | |
| Applications | |
| Molecular weight | |
| Molecular formula | C26H29FN2O2 |
| SMILES | |
| Storage | |
| Shipping | |
| Catalog no. (Mfr.) | |
| Main SKU |
Compound Overview
Levocabastine, also known as R 50547, is a potent, selective histamine H1-receptor antagonist. It is also reported as a selective, high-affinity antagonist of neurotensin receptor subtype 2 (NTR2), with a Ki of 17 nM for mNTR2 in its hydrochloride form. It can act as a VLA-4 antagonist and interferes with conjunctival eosinophil infiltration in allergic conjunctivitis (AC)[1][2][3]. It has the molecular formula C26H29FN2O2 and a molecular weight of 420.52 g/mol.
Physical & Chemical Properties
| CAS Number | 79516-68-0 |
|---|---|
| Molecular Formula | C26H29FN2O2 |
| Molecular Weight | 420.52 g/mol |
| SMILES | OC([C@@]1(C2=CC=CC=C2)[C@@H](CN([C@]3([H])CC[C@](CC3)(C4=CC=C(C=C4)F)C#N)CC1)C)=O |
| Target | H 1 Receptor, α4β1, NTR2 |
| Signaling Pathway | GPCR/G Protein; Neuronal Signaling; Immunology/Inflammation; Cytoskeleton |
| Storage | Please store the product under the recommended conditions in the Certificate of Analysis. |
| Shipping | Room temperature in continental US; may vary elsewhere. |
Biological Activity
Activity & Target
[1][2][3]
H1 Receptor |
NTR2 17 nM (Ki) |
Literature Cited
Sources cited in this description and in the In Vitro & In Vivo Data tab. Peer-reviewed publications that used this product are listed under References.
Safety
For Research Use Only. Not for use in diagnostic or therapeutic procedures, and not for human or veterinary use. Handle in accordance with your institution's chemical hygiene plan.
In Vitro
Levocabastine (0-1000 μM; HEK-293 cells) inhibits the binding of 125I-FN to the SPA bead-associated α4β1 integrin in a concentration-dependent manner, with an IC50 of 406.2 μM[3]. In vitro, Levocabastine (0-1000 μM; 30 min; Jurkat cells and EoL-1 cells) blocks α4β1 integrin/VCAM-1-mediated cell adhesion. Levocabastine inhibits α4β1 integrin-dependent adhesion to VCAM-1 with an IC50 of 395.6 μM for Jurkat cells, while EoL-1 cell adhesion is inhibited with an IC50 of 403.6 μM. Levocabastine also inhibits the adhesion of human eosinophils to VCAM-1-coated wells (IC50=443.7 μM)[3].
In Vivo
In guinea pigs infected with Parainfluenza-3 (PI-3) virus, Levocabastine (R 50547; 0.25 mg/kg; i.p.; twice a day for five days) inhibits virus-induced airway hyperresponsiveness[1]. In male C57BL/6J mice, Levocabastine (0.05 mg/kg; i.p.; once) blocks the anti-stress effect of β-LT on behavior[2]. In ovalbumin-sensitized guinea pigs, Levocabastine (500 μg/eye; drops eye; once) induces allergic conjunctivitis (AC) and markedly raises conjunctival VLA-4[3].
| Animal Model | Guinea-pig with Parainfluenza-3 (PI-3) virus[1] |
|---|---|
| Dosage | 0.25 mg/kg |
| Administration | Intraperitoneal injection; twice a day for five days |
| Result | Suppressed the influx of broncho-alveolar cells and increased in albumin content. |
| Animal Model | Male C57BL/6J mice (8-9 weeks old)[2] |
|---|---|
| Dosage | 0.05 mg/kg; 30 mg/kg (β-LT) |
| Administration | Intraperitoneal injection; once |
| Result | Blocked the anxiolytic effect of β-LT and decreased the number of head-dips. |
| Animal Model | Ovalbumin-sensitized guinea pigs[3] |
|---|---|
| Dosage | 500 μg/eye |
| Administration | drops eye, once |
| Result | Produced a noteworthy protection from allergic conjunctivitis (AC) and prevented the conjuctival elevation of VLA-4 as well as conjunctival eosinophil infiltration. |
Data provided by the manufacturer. Numbered citations refer to the Literature Cited list in the product description.
Need this compound in a format that drops straight into your assay? We can tailor formulation, chemistry, and documentation so your results stay consistent across runs and re-orders.
- Format options: solid or pre-dissolved solution (choose solvent), target concentration, aliquots, light/moisture-protected packaging
- Chemistry options: free base/acid vs salt forms, hydrate/solvate preference, stereoisomer control (single enantiomer or racemate), close analogs
- Add-on labels & handles: D/¹³C/¹⁵N isotopes (LC-MS/internal standards), azide/alkyne or other functional handles for conjugation
- QC & documentation: standard COA or enhanced analytical pack (HPLC/LC-MS/NMR), chiral purity, residual solvents, water content (KF), method-specific specs
- Scale & continuity: mg to gram scale, bulk pricing, lot reservation, repeat-order continuity
To quote quickly, tell us: compound name + CAS/structure (SMILES or mol file), intended assay context, solvent preference, salt/stereochemistry requirements, purity/QC level, and the amount (mg–g).
Can’t find the compound you’re looking for?
Send the CAS or structure and your specs. We can help source it, suggest close equivalents, or discuss custom synthesis with the right QC documentation (RUO).
RSC Med Chem. 2026 Jun 24.
PMID: 42440949
