Linopirdine

Last updated
Linopirdine
Linopirdine.svg
Clinical data
ATC code
Identifiers
  • 1-phenyl-3,3-bis(pyridin-4-ylmethyl)-1,3-dihydro-2H-indol-2-one
CAS Number
PubChem CID
IUPHAR/BPS
ChemSpider
UNII
KEGG
ChEMBL
CompTox Dashboard (EPA)
Chemical and physical data
Formula C26H21N3O
Molar mass 391.474 g·mol−1
3D model (JSmol)
  • O=C2N(c1ccccc1C2(Cc3ccncc3)Cc4ccncc4)c5ccccc5
  • InChI=1S/C26H21N3O/c30-25-26(18-20-10-14-27-15-11-20,19-21-12-16-28-17-13-21)23-8-4-5-9-24(23)29(25)22-6-2-1-3-7-22/h1-17H,18-19H2 Yes check.svgY
  • Key:YEJCDKJIEMIWRQ-UHFFFAOYSA-N Yes check.svgY
 X mark.svgNYes check.svgY  (what is this?)    (verify)

Linopirdine is a putative cognition-enhancing drug with a novel mechanism of action. Linopirdine blocks the KCNQ2\3 heteromer M current with an IC50 of 2.4 micromolar [1] disinhibiting acetylcholine release, and increasing hippocampal CA3-schaffer collateral mediated glutamate release onto CA1 pyramidal neurons. [2] In a murine model linopirdine is able to nearly completely reverse the senescence-related decline in cortical c-FOS, an effect which is blocked by atropine and MK-801, suggesting Linopirdine can compensate for the age related decline in acetylcholine release. [3] Linopirdine also blocks homomeric KCNQ1 and KCNQ4 voltage gated potassium channels which contribute to vascular tone with substantially less selectivity than KCNQ2/3. [1] Linopirdine also acts as a glycine receptor antagonist in concentrations typical for Kv7 studies in the brain. [4]

Synthesis

Linopirdine synthesis: ~90%: Patents ~90%: Linopirdine synthesis.svg
Linopirdine synthesis: ~90%: Patents ~90%:

The amide formation between diphenylamine (1) and oxalyl chloride [79-37-8] gives intermediate, CID:11594101 (2). Haworth type intramolecular cyclization of the acid chloride occurs on heating to afford 1-phenylisatin [723-89-7] (3). The reaction with 4-picoline (4) under PTC with a Quat. salt afforded the carbinol, CID:10358387 (5). Dehydration of the alcohol using acetic anhydride gives [33546-08-6] (6). The reduction of the olefin then afforded the indolone, CID:10470081 (7). The 3 position is now activated by the adjacent benzene ring on one side and the carbonyl group on the other. Alkylation with 4-picolylchloride [10445-91-7] (8) proceeds with hydroxide as the base to afford Linopirdine (9).

Related Research Articles

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An inhibitory postsynaptic potential (IPSP) is a kind of synaptic potential that makes a postsynaptic neuron less likely to generate an action potential. IPSPs were first investigated in motorneurons by David P. C. Lloyd, John Eccles and Rodolfo Llinás in the 1950s and 1960s. The opposite of an inhibitory postsynaptic potential is an excitatory postsynaptic potential (EPSP), which is a synaptic potential that makes a postsynaptic neuron more likely to generate an action potential. IPSPs can take place at all chemical synapses, which use the secretion of neurotransmitters to create cell to cell signalling. Inhibitory presynaptic neurons release neurotransmitters that then bind to the postsynaptic receptors; this induces a change in the permeability of the postsynaptic neuronal membrane to particular ions. An electric current that changes the postsynaptic membrane potential to create a more negative postsynaptic potential is generated, i.e. the postsynaptic membrane potential becomes more negative than the resting membrane potential, and this is called hyperpolarisation. To generate an action potential, the postsynaptic membrane must depolarize—the membrane potential must reach a voltage threshold more positive than the resting membrane potential. Therefore, hyperpolarisation of the postsynaptic membrane makes it less likely for depolarisation to sufficiently occur to generate an action potential in the postsynaptic neurone.

<span class="mw-page-title-main">Excitatory postsynaptic potential</span> Process causing temporary increase in postsynaptic potential

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<span class="mw-page-title-main">Neuromuscular junction</span> Junction between the axon of a motor neuron and a muscle fiber

A neuromuscular junction is a chemical synapse between a motor neuron and a muscle fiber.

<span class="mw-page-title-main">End-plate potential</span>

End plate potentials (EPPs) are the voltages which cause depolarization of skeletal muscle fibers caused by neurotransmitters binding to the postsynaptic membrane in the neuromuscular junction. They are called "end plates" because the postsynaptic terminals of muscle fibers have a large, saucer-like appearance. When an action potential reaches the axon terminal of a motor neuron, vesicles carrying neurotransmitters are exocytosed and the contents are released into the neuromuscular junction. These neurotransmitters bind to receptors on the postsynaptic membrane and lead to its depolarization. In the absence of an action potential, acetylcholine vesicles spontaneously leak into the neuromuscular junction and cause very small depolarizations in the postsynaptic membrane. This small response (~0.4mV) is called a miniature end plate potential (MEPP) and is generated by one acetylcholine-containing vesicle. It represents the smallest possible depolarization which can be induced in a muscle.

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Schaffer collaterals are axon collaterals given off by CA3 pyramidal cells in the hippocampus. These collaterals project to area CA1 of the hippocampus and are an integral part of memory formation and the emotional network of the Papez circuit, and of the hippocampal trisynaptic loop. It is one of the most studied synapses in the world and named after the Hungarian anatomist-neurologist Károly Schaffer.

<span class="mw-page-title-main">Synaptic potential</span>

Synaptic potential refers to the potential difference across the postsynaptic membrane that results from the action of neurotransmitters at a neuronal synapse. In other words, it is the “incoming” signal that a neuron receives. There are two forms of synaptic potential: excitatory and inhibitory. The type of potential produced depends on both the postsynaptic receptor, more specifically the changes in conductance of ion channels in the post synaptic membrane, and the nature of the released neurotransmitter. Excitatory post-synaptic potentials (EPSPs) depolarize the membrane and move the potential closer to the threshold for an action potential to be generated. Inhibitory postsynaptic potentials (IPSPs) hyperpolarize the membrane and move the potential farther away from the threshold, decreasing the likelihood of an action potential occurring. The Excitatory Post Synaptic potential is most likely going to be carried out by the neurotransmitters glutamate and acetylcholine, while the Inhibitory post synaptic potential will most likely be carried out by the neurotransmitters gamma-aminobutyric acid (GABA) and glycine. In order to depolarize a neuron enough to cause an action potential, there must be enough EPSPs to both depolarize the postsynaptic membrane from its resting membrane potential to its threshold and counterbalance the concurrent IPSPs that hyperpolarize the membrane. As an example, consider a neuron with a resting membrane potential of -70 mV (millivolts) and a threshold of -50 mV. It will need to be raised 20 mV in order to pass the threshold and fire an action potential. The neuron will account for all the many incoming excitatory and inhibitory signals via summative neural integration, and if the result is an increase of 20 mV or more, an action potential will occur.

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<span class="mw-page-title-main">KvLQT3</span> Protein-coding gene in the species Homo sapiens

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<span class="mw-page-title-main">KCNQ4</span> Mammalian protein found in Homo sapiens

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References

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