• 1-(4-Chlorophenyl)-4-piperidin-1-yl-1,5-dihydro-imidazol-2-one
CAS Number
PubChem CID
CompTox Dashboard (EPA)
Chemical and physical data
Molar mass277.75 g·mol−1
3D model (JSmol)
  • Clc3ccc(cc3)N1CC(=NC1=O)N2CCCCC2
  • InChI=1S/C14H16ClN3O/c15-11-4-6-12(7-5-11)18-10-13(16-14(18)19)17-8-2-1-3-9-17/h4-7H,1-3,8-10H2

ELB-139 (LS-191,811) is an anxiolytic drug with a novel chemical structure, which is used in scientific research. It has similar effects to benzodiazepine drugs, but is structurally distinct and so is classed as a nonbenzodiazepine anxiolytic.[1][2]

ELB-139 is a subtype-selective partial agonist at GABAA receptors, with highest affinity for the α3 subtype, but highest efficacy at α1 and α2.[3] It has primarily anxiolytic and anticonvulsant effects, but produces little sedative effects or ataxia,[4] and has also been demonstrated in rats to increase serotonin levels in the striatum and prefrontal cortex, without affecting dopamine levels.[5] It has been proposed as a possible candidate for a novel non-sedating anxiolytic or anticonvulsant drug for use in humans[6] The sponsor elbion AG registered a clinical trial in ClinicalTrials.gov for the treatment of anxiety associated with panic disorder but the results have not been reported.[7] It was developed by Arzneimittelwerk Dresden in the 1990s.[8]


  1. ^ Langen B, Egerland U, Bernöster K, Dost R, Unverferth K, Rundfeldt C (August 2005). "Characterization in rats of the anxiolytic potential of ELB139 [1-(4-chlorophenyl)-4-piperidin-1-yl-1,5-dihydro-imidazol-2-on], a new agonist at the benzodiazepine binding site of the GABAA receptor". The Journal of Pharmacology and Experimental Therapeutics. 314 (2): 717–24. doi:10.1124/jpet.105.084681. PMID 15860576. S2CID 21967108.
  2. ^ Atack JR (May 2005). "The benzodiazepine binding site of GABA(A) receptors as a target for the development of novel anxiolytics". Expert Opinion on Investigational Drugs. 14 (5): 601–18. doi:10.1517/13543784.14.5.601. PMID 15926867. S2CID 22793644.
  3. ^ Rabe H, Kronbach C, Rundfeldt C, Lüddens H (March 2007). "The novel anxiolytic ELB139 displays selectivity to recombinant GABA(A) receptors different from diazepam". Neuropharmacology. 52 (3): 796–801. doi:10.1016/j.neuropharm.2006.09.013. PMID 17087982. S2CID 21598180.
  4. ^ Grunwald C, Rundfeldt C, Lankau HJ, Arnold T, Höfgen N, Dost R, et al. (March 2006). "Synthesis, pharmacology, and structure-activity relationships of novel imidazolones and pyrrolones as modulators of GABAA receptors". Journal of Medicinal Chemistry. 49 (6): 1855–66. doi:10.1021/jm0509400. PMID 16539371.
  5. ^ Langen B, Rundfeldt C (January 2007). "ELB139 an agonist at the benzodiazepine binding site increases 5-HT in the striatum and prefrontal cortex of rats: a microdialysis study". Pharmacology, Biochemistry, and Behavior. 86 (1): 79–85. doi:10.1016/j.pbb.2006.12.010. PMID 17257662. S2CID 22862432.
  6. ^ Rogawski MA (June 2006). "Diverse mechanisms of antiepileptic drugs in the development pipeline". Epilepsy Research. 69 (3): 273–94. doi:10.1016/j.eplepsyres.2006.02.004. PMC 1562526. PMID 16621450.
  7. ^ Whiting PJ (February 2006). "GABA-A receptors: a viable target for novel anxiolytics?". Current Opinion in Pharmacology. 6 (1): 24–9. doi:10.1016/j.coph.2005.08.005. PMID 16359919.
  8. ^ US 5869481, "Anticonvulsive 1-ar(alk)ylimidazolin-2-ones and process for making"