Names | |
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Preferred IUPAC name N-(3-Chlorophenyl)-N′-(1-methyl-4-oxo-4,5-dihydro-1H-imidazol-2-yl)urea | |
Identifiers | |
3D model (JSmol) | |
ChEMBL | |
ChemSpider | |
ECHA InfoCard | 100.165.052 |
MeSH | Fenobam |
PubChem CID | |
UNII | |
CompTox Dashboard (EPA) | |
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Properties | |
C11H11ClN4O2 | |
Molar mass | 266.684 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Fenobam is an imidazole derivative developed by McNeil Laboratories in the late 1970s as a novel anxiolytic drug with an at-the-time-unidentified molecular target in the brain. Subsequently, it was determined that fenobam acts as a potent and selective negative allosteric modulator of the metabotropic glutamate receptor subtype mGluR5, [1] [2] and it has been used as a lead compound for the development of a range of newer mGluR5 antagonists. [3] [4] [5] [6]
Fenobam has anxiolytic effects comparable to those of benzodiazepine drugs, [1] [7] [8] but was never commercially marketed for the treatment of anxiety due to dose-limiting side effects such as amnesia and psychotomimetic symptoms. [9] [10] Following the discovery of its activity as a potent negative allosteric modulator of mGluR5, fenobam has been re-investigated for many applications, with its profile of combined antidepressant, anxiolytic, analgesic and anti-addictive effects potentially useful given the common co-morbidity of these symptoms. [11] [12] It has also shown promising initial results in the treatment of fragile X syndrome. [13] It was developed by a team at McNeil Laboratories in the 1970s. [14]
Fenobam is known to exist in five crystalline forms, all of them exhibiting a tautomeric structure with the proton attached to the five membered ring nitrogen. [15]
The glutamate receptor, metabotropic 1, also known as GRM1, is a human gene which encodes the metabotropic glutamate receptor 1 (mGluR1) protein.
Metabotropic glutamate receptor 2 (mGluR2) is a protein that, in humans, is encoded by the GRM2 gene. mGluR2 is a G protein-coupled receptor (GPCR) that couples with the Gi alpha subunit. The receptor functions as an autoreceptor for glutamate, that upon activation, inhibits the emptying of vesicular contents at the presynaptic terminal of glutamatergic neurons.
Metabotropic glutamate receptor 3 (mGluR3) is an inhibitory Gi/G0-coupled G-protein coupled receptor (GPCR) generally localized to presynaptic sites of neurons in classical circuits. However, in higher cortical circuits in primates, mGluR3 are localized post-synaptically, where they strengthen rather than weaken synaptic connectivity. In humans, mGluR3 is encoded by the GRM3 gene. Deficits in mGluR3 signaling have been linked to impaired cognition in humans, and to increased risk of schizophrenia, consistent with their expanding role in cortical evolution.
Metabotropic glutamate receptor 4 is a protein that in humans is encoded by the GRM4 gene.
Metabotropic glutamate receptor 5 is an excitatory Gq-coupled G protein-coupled receptor predominantly expressed on the postsynaptic sites of neurons. In humans, it is encoded by the GRM5 gene.
LY-341495 is a research drug developed by the pharmaceutical company Eli Lilly, which acts as a potent and selective orthosteric antagonist for the group II metabotropic glutamate receptors (mGluR2/3).
2-Methyl-6-(phenylethynyl)pyridine (MPEP) is a research drug which was one of the first compounds found to act as a selective antagonist for the metabotropic glutamate receptor subtype mGluR5. After being originally patented as a liquid crystal for LCDs, it was developed by the pharmaceutical company Novartis in the late 1990s. It was found to produce neuroprotective effects following acute brain injury in animal studies, although it was unclear whether these results were purely from mGluR5 blockade as it also acts as a weak NMDA antagonist, and as a positive allosteric modulator of another subtype mGlu4, and there is also evidence for a functional interaction between mGluR5 and NMDA receptors in the same populations of neurons. It was also shown to produce antidepressant and anxiolytic effects in animals, and to reduce the effects of morphine withdrawal, most likely due to direct interaction between mGluR5 and the μ-opioid receptor.
3-( ethynyl)pyridine (MTEP) is a research drug that was developed by Merck & Co. as a selective allosteric antagonist of the metabotropic glutamate receptor subtype mGluR5. Identified through structure-activity relationship studies on an older mGluR5 antagonist MPEP, MTEP has subsequently itself acted as a lead compound for newer and even more improved drugs.
ADX-47273 is a research pharmaceutical developed by Addex Therapeutics which acts as a positive allosteric modulator (PAM) selective for the metabotropic glutamate receptor subtype mGluR5. It has nootropic and antipsychotic effects in animal studies, and has been used as a lead compound to develop improved derivatives.
SIB-1757 is a drug used in scientific research which was one of the first compounds developed that acts as a selective antagonist for the metabotropic glutamate receptor subtype mGluR5. It has anti-hyperalgesia effects in animals. SIB-1757 along with other mGluR5 antagonists has been shown to have neuroprotective and hepatoprotective effects, and it is also used to study the role of the mGluR5 receptor in brain development.
SIB-1893 is a drug used in scientific research which was one of the first compounds developed that acts as a selective antagonist for the metabotropic glutamate receptor subtype mGluR5. It has anticonvulsant and neuroprotective effects, and reduces glutamate release. It has also been found to act as a positive allosteric modulator of mGluR4.
CDPPB is a drug used in scientific research which acts as a positive allosteric modulator selective for the metabotropic glutamate receptor subtype mGluR5. It has antipsychotic effects in animal models, and mGluR5 modulators are under investigation as potential drugs for the treatment of schizophrenia, as well as other applications.
Ro67-4853 is a drug used in scientific research, which acts as a selective positive allosteric modulator for the metabotropic glutamate receptor subtype mGluR1. It was derived by modification of the simpler compound Ro01-6128, and has itself subsequently been used as a lead compound to develop a range of potent and selective mGluR1 positive modulators.
LY-487,379 is a drug used in scientific research that acts as a selective positive allosteric modulator for the metabotropic glutamate receptor group II subtype mGluR2. It is used to study the structure and function of this receptor subtype, and LY-487,379 along with various other mGluR2/3 agonists and positive modulators are being investigated as possible antipsychotic and anxiolytic drugs.
CECXG (3'-ethyl-LY-341,495) is a research drug which acts as a potent and selective antagonist for the group II metabotropic glutamate receptors (mGluR2/3), with reasonable selectivity for mGluR3. While it is some five times less potent than LY-341,495 at mGluR3, it has 38x higher affinity for mGluR3 over mGluR2, making it one of the few ligands available that is able to distinguish between these two closely related receptor subtypes.
CTEP (Ro4956371) is a research drug developed by Hoffmann-La Roche that acts as a selective allosteric antagonist of the metabotropic glutamate receptor subtype mGluR5, binding with nanomolar affinity and over 1000 times selectivity over all other receptor targets tested. In animal studies it was found to have a high oral bioavailability and a long duration of action, lasting 18 hours after a single dose, giving it considerably improved properties over older mGluR5 antagonists such as MPEP and fenobam.
MGS-0039 is a drug that is used in neuroscientific research, which acts as a potent and selective antagonist for group II of the metabotropic glutamate receptors (mGluR2/3). It produces antidepressant and anxiolytic effects in animal studies, and has been shown to boost release of dopamine and serotonin in specific brain areas. Research has suggested this may occur through a similar mechanism as that suggested for the similarly glutamatergic drug ketamine.
GRN-529 is a drug that was developed by Wyeth as a negative allosteric modulator of the metabotropic glutamate receptor 5 (mGluR5).
MFZ 10-7 is a drug with potential applications in the treatment of addiction, which acts as a negative allosteric modulator of the metabotropic glutamate receptor subtype 5 (mGluR5). Others of the kind, namely MPEP & MTEP, are not considered to have translational potential for human use due to off-target effects and short half-lives. Drugs of this kind have been used to offset craving for drugs of abuse such as cocaine in in vivo animal administration models.
AZD 9272 is a drug which acts as a selective antagonist for the metabotropic glutamate receptor subtype mGluR5. It was unsuccessful in human trials as an analgesic, but continues to be widely used in research especially as its radiolabelled forms.