| Size | Price | Stock | Qty |
|---|---|---|---|
| 1mg |
|
||
| Other Sizes |
| Targets |
I1-imidazoline receptor (primary), alpha2-adrenergic receptor, Monoamine Oxidase A (MAO-A). Harmane-d (harmane-d1) is the deuterium-labeled form of harmane. Harmane is a beta-carboline alkaloid that acts as a high-affinity ligand for the I1-imidazoline receptor (IC50 = 30 nM), with 1000-fold selectivity over the alpha2-adrenergic receptor (IC50 = 18 microM). It is also a reversible and selective inhibitor of monoamine oxidase A (MAO-A). The I1-imidazoline receptor is a non-adrenergic, non-dopaminergic binding site involved in the central regulation of blood pressure, neuroprotection, and other CNS functions. Harmane's interaction with the I1 receptor has implications for hypertension and neuroprotection. The MAO-A inhibition may contribute to its effects on monoamine neurotransmitters (serotonin, norepinephrine, dopamine). Harmane also binds to the benzodiazepine binding site of GABA_A receptors, contributing to its neurotoxic effects (tremor). The deuterium label (d1) does not alter the binding affinity or pharmacological properties of the parent compound. This product is used as an analytical standard.
|
|---|---|
| ln Vitro |
Drug compounds have included stable heavy isotopes of carbon, hydrogen, and other elements, mostly as tracers for quantification throughout the drug development process. Due to its potential to alter the pharmacokinetic and metabolic characteristics of medications, deuteration has drawn attention[1].
In vitro, Harmane (the non-labeled parent compound) is a high-affinity ligand for the I1-imidazoline receptor, with an IC50 of 30 nM, and is 1000-fold selective over the alpha2-adrenergic receptor (IC50 = 18 uM). It is also a reversible inhibitor of monoamine oxidase A (MAO-A). In SH-SY5Y neuroblastoma cells, harmane (1-100 uM) inhibits MAO-A activity, leading to increased levels of monoamines. At higher concentrations, it induces neurotoxicity and apoptosis. In rat brain synaptosomes, harmane inhibits the uptake of serotonin, dopamine, and norepinephrine. In receptor binding assays, harmane also binds to the benzodiazepine site of the GABA_A receptor, with IC50 in the low micromolar range. The deuterated analog, Harmane-d, is not typically used in these activity assays; it is used as an internal standard for mass spectrometry. Therefore, no specific in vitro activity data are available for the labeled compound. The unlabeled harmane also induces tremor in animal models and is a component of the tremorgenic beta-carbolines. The TFA salt is not used; the compound is Harmane-d in its free base form. |
| ln Vivo |
In vivo, harmane (the non-labeled parent compound) is a potent tremorgenic neurotoxin. In rodents, systemic administration (intraperitoneal or subcutaneous) of harmane (5-50 mg/kg) produces dose-dependent action tremors (postural tremor, kinetic tremor), which are reversible and selective. The tremor is thought to be mediated by binding to the GABA_A receptor benzodiazepine site and by its effect on inferior olive neurons. Harmane is also known to produce other behavioral effects, including anxiety, hallucinations, and increased startle response. The deuterated analog, Harmane-d, is not used for in vivo efficacy studies; it is used as an internal standard for pharmacokinetic or toxicokinetic studies. When administered as a tracer, Harmane-d (0.1-1 mg/kg, i.v.) is used to quantitate the distribution and metabolism of harmane in the body. The compound is a research chemical and is not intended for therapeutic use. Harmane-d is not a drug; it is a stable isotope-labeled analytical standard.
|
| Enzyme Assay |
For non-cellular binding assays, a radioligand binding assay for the I1-imidazoline receptor can be performed using rat brain membranes (frontal cortex, hippocampus). Prepare membranes by homogenizing tissue in binding buffer (50 mM Tris-HCl pH 7.4, 5 mM EDTA, 1 mM MgCl2). In 96-well plates, incubate membranes (100-200 ug protein) with 1-2 nM [3H]-clonidine (or [3H]-idazoxan in the presence of 10 uM rauwolscine to block alpha2-adrenergic receptors) and varying concentrations of unlabeled Harmane (0.01-10000 nM) in buffer for 60-90 minutes at 25degC. Non-specific binding is determined in the presence of 10 uM clonidine or 1 uM efaroxan (I1 antagonist). Separate bound and free radioligand by rapid filtration through GF/B filters pre-soaked in 0.3% polyethyleneimine (PEI). Quantify bound radioactivity by liquid scintillation counting. IC50 is determined, and Ki is calculated using the Cheng-Prusoff equation. Harmane has a Ki of 30 nM for the I1 receptor. For MAO-A inhibition assays, use recombinant human MAO-A enzyme. Incubate enzyme (0.1-1 ug) with varying concentrations of harmane (0.1-1000 nM) in assay buffer (100 mM potassium phosphate pH 7.4) for 15 min. Add the substrate kynuramine (50-100 uM) and incubate for 30-60 min. Terminate with 2 N NaOH, extract product (4-hydroxyquinoline) into cyclohexane, and measure fluorescence (excitation 315 nm, emission 380 nm). IC50 is calculated. Harmane-d can be used as a competitor in these assays if needed, but it is not routine.
|
| Cell Assay |
For cell-based assays, the unlabeled compound is used. Harmane-d is not typically used for cellular activity assays because the deuterium label does not alter activity, but it is more expensive. For reference, SH-SY5Y human neuroblastoma cells are cultured in DMEM/F12 with 10% FBS. Seed cells in 96-well plates (5-10 × 10^3 cells/well) or 6-well plates (2-5 × 10^5 cells/well). Treat with harmane (0.1-1000 uM) for 24-72 hours. For cell viability, use MTT or CellTiter-Glo. Harmane exhibits cytotoxicity at concentrations >50 uM. For MAO-A activity in cells, treat cells for 24 hours, then wash, lyse, and measure MAO-A activity using a fluorometric MAO assay kit (e.g., Abcam). For measurement of monoamines, treat cells for 4-24 hours, then lyse and measure serotonin, dopamine, norepinephrine by HPLC-ECD or by ELISA. Harmane should increase monoamine levels due to MAO-A inhibition. For receptor binding assays on live cells, use cells expressing I1-imidazoline receptors (e.g., PC12 cells, which naturally express I1 sites). Incubate cells with [3H]-clonidine and varying concentrations of harmane for 60 min at 4degC, wash, and quantify bound radioactivity. Harmane-d can be used as a tracer for uptake or distribution studies by adding it to cells and measuring intracellular concentration by LC-MS/MS. However, this is not a standard protocol. The TFA salt is not used; the compound is the free base. Harmane-d (d1) is an analytical standard, not a pharmacological tool for cell-based assays.
|
| Animal Protocol |
For in vivo studies, Harmane-d is not used as a pharmacologically active agent; it is used as an internal standard in LC-MS/MS bioanalysis of harmane. For pharmacokinetic studies of harmane, CD-1 mice or Sprague-Dawley rats are administered harmane (5-10 mg/kg, i.p.) or harmane-d (as a tracer). Blood is collected at 0, 5, 15, 30, 60, 120, 240, 480 minutes post-dose. Plasma (50 uL) is mixed with acetonitrile containing a known concentration of Harmane-d as an internal standard. After protein precipitation, the supernatant is analyzed by LC-MS/MS in positive ion electrospray mode (MRM transition for harmane: m/z 183.1 → 115.1; for harmane-d: m/z 184.1 → 116.1). The amount of harmane in the sample is calculated from a calibration curve (harmane standards prepared in blank plasma) using the ratio of harmane peak area to harmane-d peak area. PK parameters (AUC, Cmax, Tmax, t1/2, CL, Vd) are calculated. This is the primary in vivo application of the deuterated compound. For distribution studies, tissues (brain, liver, kidney, lung) are harvested, homogenized, and processed similarly. Harmane-d is not used for efficacy studies (e.g., tremor measurement). All animal procedures require IACUC approval.
|
| ADME/Pharmacokinetics |
As an internal standard, Harmane-d is not used in pharmacokinetic studies to determine its own PK properties; rather, it is used to quantify the unlabeled harmane. However, its PK properties are expected to be essentially identical to those of harmane, as the kinetic isotope effect (KIE) for a single deuterium atom is minimal. Harmane (and by extension Harmane-d) is a lipophilic, small-molecule (MW 183.23) beta-carboline alkaloid. It is rapidly absorbed after intraperitoneal or subcutaneous administration, with peak plasma concentrations (Cmax) reached within 15-30 minutes (Tmax). The plasma half-life (t1/2) in rodents is estimated to be 1-3 hours. It crosses the blood-brain barrier (BBB) due to its lipophilicity (logP ~1.5-2.5). It is extensively metabolized in the liver by cytochrome P450 enzymes (CYP2A6, CYP2D6, CYP1A2) via N-oxidation, O-demethylation, and aromatic hydroxylation. Metabolites are excreted in urine and bile. Plasma protein binding is moderate to high (~80-90%). The deuterium label is stable and does not exchange back to hydrogen under physiological conditions. Harmane-d is an analytical standard and is not intended for in vivo administration as a therapeutic agent.
|
| Toxicity/Toxicokinetics |
No specific toxicity data are available for Harmane-d (deuterium-labeled Harmane). The toxicity profile of the unlabeled parent compound Harmane is well documented. Harmane is a potent neurotoxin that causes severe action tremors and psychiatric manifestations (hallucinations, anxiety) at doses of 5-50 mg/kg in rodents. The tremor is dose-dependent and reversible. At higher doses (>50 mg/kg), harmane can cause convulsions, respiratory depression, and death. Chronic exposure to harmane has been linked to increased risk of essential tremor, Parkinson's disease, and certain cancers. In vitro, harmane is cytotoxic to neuroblastoma cells at concentrations >50 uM. The deuterated analog (Harmane-d) is expected to have the same toxicity profile because the isotopic substitution does not alter its pharmacological activity. However, because the deuterated compound is used only in small quantities (milligrams) as an analytical standard, the risk of exposure to toxic levels is low. Standard laboratory safety precautions (gloves, lab coat, fume hood) should be used when handling Harmane-d due to its neurotoxic potential. The compound is for research use only and is not approved for human use. The TFA salt is not used; the product is the free base.
|
| References |
[1]. Russak EM, et al. Impact of Deuterium Substitution on the Pharmacokinetics of Pharmaceuticals. Ann Pharmacother. 2019;53(2):211-216.
[2]. Louis ED, et, al. Blood harmane concentrations and dietary protein consumption in essential tremor. Neurology. 2005 Aug 9;65(3):391-6. [3]. Musgrave IF, et, al. Harmane produces hypotension following microinjection into the RVLM: possible role of I(1)-imidazoline receptors. Br J Pharmacol. 2000 Mar;129(6):1057-9. [4]. Glover V, et, al. β-Carbolines as selective monoamine oxidase inhibitors:In vivo implications [5]. Umezawa K, et, al. Comutagenic effect of norharman and harman with 2-acetylaminofluorene derivatives. Proc Natl Acad Sci U S A. 1978 Feb;75(2):928-30. |
| Additional Infomation |
Harmane (harman or 1-methyl-beta-carboline) is a naturally occurring beta-carboline alkaloid found in a variety of plants, coffee, and cooked meats (especially well-done meat). It is formed during the Maillard reaction and is present in tobacco smoke. Harmane is a potent neurotoxin that induces action tremors in animals and has been implicated in the pathophysiology of essential tremor (ET) in humans. It is also a high-affinity ligand for the I1-imidazoline receptor (IC50 = 30 nM) and a reversible inhibitor of monoamine oxidase A (MAO-A). Harmane has been studied for its potential neuroprotective properties via I1 receptors, but its tremorgenic and psychotomimetic effects limit its therapeutic potential. Deuterium-labeled Harmane (Harmane-d, Harmane-d1) is used as an internal standard for LC-MS/MS quantification of harmane in biological samples, e.g., in clinical studies measuring harmane levels in plasma, urine, and brain tissue. This product is not a drug; it is a stable isotope-labeled research reagent. As of 2026, harmane is not an approved drug. Harmane-d is for research use only and is not intended for human or veterinary use.
|
| Molecular Formula |
C12H9DN2
|
|---|---|
| Molecular Weight |
183.23
|
| Related CAS # |
Harmane;486-84-0;Harmane-d2
|
| Appearance |
Typically exists as solid at room temperature
|
| HS Tariff Code |
2934.99.9001
|
| Storage |
Powder -20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month |
| Shipping Condition |
Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)
|
| Solubility (In Vitro) |
DMSO :~50 mg/mL (~272.88 mM)
|
|---|---|
| Solubility (In Vivo) |
Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples.
Injection Formulations
Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)(e.g. IP/IV/IM/SC) *Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution. Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline) Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil) Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals). View More
Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)] Oral Formulations
Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium) Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals). View More
Oral Formulation 3: Dissolved in PEG400 (Please use freshly prepared in vivo formulations for optimal results.) |
| Preparing Stock Solutions | 1 mg | 5 mg | 10 mg | |
| 1 mM | 5.4576 mL | 27.2881 mL | 54.5762 mL | |
| 5 mM | 1.0915 mL | 5.4576 mL | 10.9152 mL | |
| 10 mM | 0.5458 mL | 2.7288 mL | 5.4576 mL |
*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.
Calculation results
Working concentration： mg/mL；
Method for preparing DMSO stock solution： mg drug pre-dissolved in μL DMSO (stock solution concentration mg/mL). Please contact us first if the concentration exceeds the DMSO solubility of the batch of drug.
Method for preparing in vivo formulation:：Take μL DMSO stock solution, next add μL PEG300, mix and clarify, next addμL Tween 80, mix and clarify, next add μL ddH2O，mix and clarify.
(1) Please be sure that the solution is clear before the addition of next solvent. Dissolution methods like vortex, ultrasound or warming and heat may be used to aid dissolving.
(2) Be sure to add the solvent(s) in order.
Products are for research use only; We do not sell to patients
Copyright 2020 InvivoChem LLC | All Rights Reserved
