δ Opioid Receptor/DOR; mAChR1

N-desmethylclozapine, a brain penetrant metabolite, was found to bind to M1 muscarinic receptors preferentially, with an IC50 of 55 nM. Compared to clozapine, it was a more potent partial agonist at this receptor, with an EC50 of 115 nM and 50% of acetylcholine response[1].
N-desmethylclozapine has agonistic characteristics at the 5-HT1A receptor in the cerebral cortex and hippocampus, as well as mild agonistic effects on the M1 mAChR. Additionally, this substance exhibits agonistic behavior at the δ-opioid receptor located in the striatum and cerebral cortex[2].
N-desmethylclozapine (3 μM) significantly reduces excitatory neurons' outward current, but not that of inhibitory neurons. When it comes to excitatory neurons, N-desmethylclozapine works better on its own than it does when combined with clozapine or taken alone. One microgram of atropine and 0.1 microgram of pirenzepine both considerably reduce the effects of N-desmethylclozapine on excitatory neurons. In excitatory cells, K¹²⁵ channels were inhibited by N-desmethylclozapine but not by clozapine via M1 receptors[3].
N-desmethylclozapine causes TxB2 levels to drop both in response to TSST-1 stimulation and in unstimulated conditions. The production of TxA2 or TxB2 may be modulated by clozapine, N-desmethylclozapine, and CPZ, potentially affecting neurotransmitter systems[5].
N-desmethylclozapine, fluoxetine hydrochloride, and salmeterol xinafoate have IC50 values of 1 μM, 0.38 μM, and 0.67 μM in Huh-7 cells infected with DENV-2, respectively. When cells treated with all three inhibitors are compared to those treated with DMSO, the levels of NS3 are lower, indicating that the inhibitors function at a stage before the translation of viral proteins. Negative-strand RNA levels are reduced by >75% in cells treated with N-desmethylclozapine[6].

N-desmethylclozapine underlies presynaptic modulation of glutamate release and GABA in humans and rats at M2 and M4 mAChRs, respectively. N-desmethylclozapine, for example, may be an M2 mAChR antagonist in rats, but it is not active at this receptor in the human neocortex. On the other hand, N-desmethylclozapine does not have an agonistic effect at M4 mAChR in the rat neocortex[4].

Metabolism / Metabolites
N-Desmethylclozapine has known human metabolites that include Desmethylclozapine N-glucuronide.
N-Desmethylclozapine is a known human metabolite of clozapine.

[1]. N-desmethylclozapine, a major metabolite of clozapine, increases cortical acetylcholine and dopamine release in vivo via stimulation of M1 muscarinic receptors. Neuropsychopharmacology. 2005 Nov;30(11):1986-95.

[2]. Comparative analysis of pharmacological properties of xanomeline and N-desmethylclozapine in rat brain membranes. J Psychopharmacol. 2016 Sep;30(9):896-912.

[3]. Electrophysiological evidence showing muscarinic agonist-antagonist activities of N-desmethylclozapine using hippocampal excitatory and inhibitory neurons. Brain Res. 2016 Jul 1;1642:255-62.

[4]. Different pharmacology of N-desmethylclozapine at human and rat M2 and M 4 mAChRs in neocortex. Naunyn Schmiedebergs Arch Pharmacol. 2015 May;388(5):487-96.

[5]. Impact of clozapine, N-desmethylclozapine and chlorpromazine on thromboxane production in vitro. Med Chem. 2012 Nov;8(6):1032-8.

[6]. N-Desmethylclozapine, Fluoxetine and Salmeterol inhibit post-entry stages of dengue virus life-cycle. Antimicrob Agents Chemother. 2016 Aug 29.

N-desmethylclozapine is a dibenzodoazepine substituted with chloro and piperazino groups which is a major metabolite of clozapine; a potent and selective 5-HT2C serotonin receptor antagonist. It has a role as a metabolite, a delta-opioid receptor agonist and a serotonergic antagonist. It is a dibenzodiazepine, a member of piperazines and an organochlorine compound.
ACP-104, or N-desmethylclozapine, is the major metabolite of clozapine, and is being developed by ACADIA as a novel, stand-alone therapy for schizophrenia. It combines an atypical antipsychotic efficacy profile with the added potential benefit of enhanced cognition, thereby addressing one of the major challenges in treating schizophrenia today.

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Drug Indication
Investigated for use/treatment in schizophrenia and schizoaffective disorders.

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Mechanism of Action
ACP-104 combines M1 muscarinic agonism, 5-HT2A inverse agonism, and D2 and D3 dopamine partial agonism in a single compound. ACP-104 uniquely stimulates brain cells known as M1 muscarinic receptors that play an important role in cognition. ACP-104 is a partial-agonist that causes weak activation of dopamine D2 and D3 receptors. These partial agonist properties of ACP-104 may lead to less motoric side effects than seen with most other antipsychotic drugs.

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Pharmacodynamics
ACP-104 is a small molecule drug candidate we are developing as a novel therapy for schizophrenia. It is known that large amounts of ACP-104, or N-desmethylclozapine, are formed in the body after administration of clozapine. That is, clozapine is metabolized to ACP-104. We discovered that ACP-104 has a unique ability to stimulate m1 muscarinic receptors, a key muscarinic receptor. The m1 muscarinic receptors are widely known to play an important role in cognition. Since clozapine itself blocks the m1 muscarinic receptor, patients need to extensively metabolize clozapine into ACP-104 to stimulate this receptor and thereby overcome the blocking action of clozapine. Administration of ACP-104 will avoid the variability of this metabolic process and the competing action of clozapine. Like clozapine, ACP-104 is a dopamine antagonist and a 5-HT2A inverse agonist. We believe that ACP-104 represents a new approach to schizophrenia therapy that combines an atypical antipsychotic efficacy profile with the added advantage of beneficial cognitive effects.

C17H17CLN4

312.797

312.114

C, 65.28; H, 5.48; Cl, 11.33; N, 17.91

6104-71-8

N-Desmethylclozapine-d8; 1189888-77-4; N-Desmethylclozapine-d8 hydrochloride; 2705402-91-9

135409468

Light yellow to green yellow solid powder

1.38g/cm3

490.1ºC at 760 mmHg

120-125°C

250.2ºC

1.709

3.22

2

3

1

22

421

0

ClC1=CC=C2C(N=C(N3CCNCC3)C4=CC=CC=C4N2)=C1

JNNOSTQEZICQQP-UHFFFAOYSA-N

InChI=1S/C17H17ClN4/c18-12-5-6-15-16(11-12)21-17(22-9-7-19-8-10-22)13-3-1-2-4-14(13)20-15/h1-6,11,19-20H,7-10H2

3-chloro-6-piperazin-1-yl-11H-benzo[b][1,4]benzodiazepine

AZD-5991; AZD-5991 S-enantiomer; AZD 5991 S-enantiomer.

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO: ≥ 50 mg/mL (~159.9 mM)

Solubility in Formulation 1: ≥ 2.5 mg/mL (7.99 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 2.5 mg/mL (7.99 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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 (Please use freshly prepared in vivo formulations for optimal results.)