emapunil   Click here for help

GtoPdb Ligand ID: 8704

Synonyms: AC-5216 | XBD-173 | XBD173
Compound class: Synthetic organic
Comment: Emapunil (XBD173) is an orally bioavailable translocator protein (TSPO) phenylpurine ligand. TSPO was originally identified as a molecular target for the development of new anxiolytic drugs [1-2,5]. More recently, TSPO is being pursued as a novel neuroimmunodulatory target for disease-modifying benefit in secondary progressive MS (SPMS), based on preclinical evidence of immunomodulatory effects on monocytes/macrophages and microglia that appear to induce a reparative phenotype in these immune cell types [3-4].
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2D Structure
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Physico-chemical Properties
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Hydrogen bond acceptors 5
Hydrogen bond donors 0
Rotatable bonds 7
Topological polar surface area 73.02
Molecular weight 401.19
XLogP 2.65
No. Lipinski's rules broken 0
SMILES / InChI / InChIKey
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Canonical SMILES CCN(C(=O)Cn1c2nc(ncc2n(c1=O)C)c1ccccc1)Cc1ccccc1
Isomeric SMILES CCN(C(=O)Cn1c2nc(ncc2n(c1=O)C)c1ccccc1)Cc1ccccc1
InChI InChI=1S/C23H23N5O2/c1-3-27(15-17-10-6-4-7-11-17)20(29)16-28-22-19(26(2)23(28)30)14-24-21(25-22)18-12-8-5-9-13-18/h4-14H,3,15-16H2,1-2H3
InChI Key NBMBIEOUVBHEBM-UHFFFAOYSA-N
Bioactivity Comments
In human brain samples the TSPO binding affinity of emapunil (XBD173) varies depending on the expression profile of binding sites [3]. Some individuals express a protein with either a high or low affinity binding site, and others express both so the detected overall binding affinity lies between the high and low values.
Selectivity at other protein targets
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Target Sp. Type Action Value Parameter Concentration range (M) Reference
Translocator protein Primary target of this compound Rn Agonist Agonist 9.7 pKi - 6
pKi 9.7 (Ki 2x10-10 M) [6]
Translocator protein Hs Agonist Binding 7.5 – 8.6 pKi - 3
pKi 8.6 (Ki 2.4x10-9 M) [3]
Description: Affinity for the high affinity TSPO binding site in human brain tissue
pKi 7.5 (Ki 3.03x10-8 M) [3]
Description: Affinity for the low affinity TSPO binding site in human brain tissue