Buy Talsupram (Lu 5-005 or Lu 5-003[1]) Cas 21489-20-3
Buy Talsupram (Lu 5-005 or Lu 5-003[1]) Cas 21489-20-3
Buy Talsupram (Lu 5-005 or Lu 5-003[1]) Cas 21489-20-3
Talsupram (Lu 5-005 or Lu 5-003[1]) is a selective norepinephrine reuptake inhibitor (NRI) which was investigated as an antidepressant in the 1960s and 1970s but was never marketed.[2][3][4] Along with talopram, it is structurally related to the selective serotonin reuptake inhibitor (SSRI) citalopram.[5]
See also
Talsupram
Technical Parameters
Basic Identity
| Product Name | Talsupram |
|---|---|
| CAS | 21489-20-3 |
| Synonyms |
1-(3-methylaminopropyl)-1-phenyl-3,3-dimethylthiophthalane hydrochloride, Lu 5-003, talsupram
|
| Molecular Formula | C20H25NS |
| Molecular Weight | 311.5 g/mol |
Structural Identifiers
| SMILES | CC1(C2=CC=CC=C2C(S1)(CCCNC)C3=CC=CC=C3)C |
|---|---|
| InChI | InChI=1S/C20H25NS/c1-19(2)17-12-7-8-13-18(17)20(22-19,14-9-15-21-3)16-10-5-4-6-11-16/h4-8,10-13,21H,9,14-15H2,1-3H3 |
| InChIKey | FKHYYOUFMJBLAF-UHFFFAOYSA-N |
Commercial & Availability
Structure & Identifiers
Talsupram (CAS 21489-20-3): A High-Affinity, Selective Norepinephrine Reuptake Inhibitor (NRI) for Neuropharmacology Research
Talsupram (Lu 5-005) is a selective norepinephrine reuptake inhibitor (NRI) that was originally investigated as an antidepressant in the 1960s and 1970s but was never commercialized [1]. It is structurally related to the selective serotonin reuptake inhibitor (SSRI) citalopram, but features a key structural variation that redirects its pharmacological profile [2]. Talsupram is a high-affinity ligand for the norepinephrine transporter (NET) and is primarily used in research settings to selectively probe the role of noradrenergic signaling, including its application in neuropathic pain models [3].
Why Norepinephrine Reuptake Inhibitors (NRIs) Like Talsupram Are Not Interchangeable
The class of norepinephrine reuptake inhibitors (NRIs) exhibits significant variation in both molecular structure and functional pharmacology, making generic substitution scientifically unsound. Talsupram’s benzothiophene core differentiates it from analogs like talopram (isobenzofuran core) and desipramine (tricyclic core), which in turn leads to distinct transporter binding affinities and selectivity profiles . Furthermore, in vivo functional outcomes, such as anti-hyperalgesic efficacy, have been shown to differ between talsupram and other monoamine reuptake inhibitors, underscoring that in-class potency does not directly translate to equivalent phenotypic effects [1].
Quantitative Evidence for Talsupram Differentiation vs. Closest Analogs
Superior Binding Affinity and Functional Inhibition of NET vs. Closest Structural and Pharmacological Analogs
Talsupram exhibits superior affinity and functional inhibition for the norepinephrine transporter (NET) compared to its closest structural analog, talopram, and other benchmark NRIs. Its IC50 for human NET inhibition is 0.79 nM, which is >3-fold more potent than talopram (IC50 = 2.9 nM) and >5-fold more potent than desipramine (Ki = 4 nM) . In rat brain tissue, talsupram’s Ki of 0.79 nM for NET is >5-fold lower than talopram’s Ki of 4.5 nM [1][2].
Enhanced NET Selectivity Profile Over SERT and DAT Compared to Other NRIs
Talsupram demonstrates a highly selective functional inhibition profile for NET over SERT and DAT. The IC50 for NET (0.79 nM) is >1000-fold lower than for SERT (850 nM) and >11,000-fold lower than for DAT (9300 nM) . This selectivity window is numerically larger than that observed for reboxetine in rat transporters (Ki NET = 1.1 nM, SERT = 129 nM, DAT >10,000 nM; ~117-fold over SERT) and substantially larger than that for atomoxetine (Ki NET = 5 nM, SERT = 77 nM, DAT = 1451 nM; ~15-fold over SERT) [1].
Differentiated Analgesic Efficacy in a Preclinical Model of Neuropathic Pain
In a rat model of neuropathic pain (partial sciatic nerve ligation), talsupram demonstrated significantly superior anti-hyperalgesic efficacy compared to vilazodone (a SERT inhibitor/5-HT1A partial agonist) and indatraline (a triple reuptake inhibitor) in the hot plate test, a supraspinal pain response assay [1][2]. Talsupram produced a higher percentage of maximal possible effect (MPE) at multiple doses, with the study concluding it was ‘significantly more effective’ than the other two drugs in this test [1].
Structural Basis for Pharmacological Differentiation: The Benzothiophene Core
Talsupram is structurally differentiated from its closest analog, talopram, by a single heteroatom substitution in its tricyclic core. Talsupram contains a benzothiophene ring (sulfur heteroatom), whereas talopram contains an isobenzofuran ring (oxygen heteroatom) [1]. This seemingly minor structural change results in a >3-fold increase in NET inhibitory potency (IC50 = 0.79 nM for talsupram vs. 2.9 nM for talopram) and a distinct selectivity profile . This represents a clear structure-activity relationship (SAR) where replacing oxygen with sulfur significantly enhances NET engagement.
CNS Penetration Liability: A Critical Limitation for In Vivo Brain Target Engagement
Despite its high in vitro potency and selectivity, talsupram exhibits poor blood-brain barrier (BBB) penetration. PET imaging studies in a rhesus monkey and biodistribution studies in rats demonstrated that radiolabeled [11C]talsupram ‘did not enter the CNS in adequate amounts to be used in PET imaging studies’ [1]. This was despite the compound’s high affinity and selectivity for NET in vitro, confirming that its BBB penetration is a significant translational limitation compared to CNS-penetrant NRIs like atomoxetine or reboxetine.
Defined Research and Industrial Applications for Talsupram Based on Its Specific Profile
Use as a High-Potency, Selective NET Inhibitor for In Vitro and Ex Vivo Pharmacology
Talsupram’s sub-nanomolar potency and high selectivity for NET over SERT and DAT make it an ideal tool compound for in vitro assays requiring clean noradrenergic target engagement. Applications include radioligand binding displacement studies, functional uptake assays in cells or synaptosomes, and ex vivo tissue studies where CNS penetration is not a requirement [1]. Its superior potency compared to talopram and greater selectivity compared to atomoxetine provide a higher degree of pharmacological precision [2].
A Validated Tool for Probing Noradrenergic Mechanisms in Rodent Models of Neuropathic Pain
Based on direct comparative in vivo evidence, talsupram is a validated research tool for studying the specific contribution of noradrenergic reuptake inhibition to analgesia in neuropathic pain models, such as the partial sciatic nerve ligation model in rats [1]. Its superior efficacy in the hot plate test over vilazodone and indatraline provides a specific, data-backed rationale for its selection in studies aimed at isolating the analgesic effects of NET inhibition from those of SERT or DAT modulation [1].
Chemical Probe and Scaffold for Medicinal Chemistry SAR Studies
The benzothiophene core of talsupram serves as a potent starting point for structure-activity relationship (SAR) studies aimed at developing novel NET inhibitors. Its >3-fold potency advantage over the oxygen-containing analog talopram provides a clear design hypothesis for optimizing NET affinity and selectivity [1]. Researchers can use talsupram as a benchmark in medicinal chemistry programs focused on scaffold hopping or improving drug-like properties for CNS penetration.
A Cautionary Tale in Translational Pharmacology for CNS Drug Development
The well-documented failure of talsupram to achieve adequate brain penetration despite exceptional in vitro potency makes it a valuable negative control or case study. It serves as a benchmark compound for demonstrating that high in vitro affinity and selectivity do not guarantee in vivo CNS target engagement, a critical concept in translational neuropharmacology [1]. This property distinguishes it from CNS-active NRIs like reboxetine and atomoxetine.
Technical Documentation Hub
Structured technical reading across foundational, methodological, troubleshooting, and validation/comparative pathways. Use the hub when you need more detail before procurement.
38 linked technical documents
Talsupram: A Technical Guide to its Mechanism of Action as a Selective Norepinephrine Reuptake Inhibitor
A Technical Guide to the Selective Norepinephrine Reuptake Inhibitor Properties of Talsupram
Talsupram: A Technical Guide to its Chemical Structure, Synthesis, and Biological Activity
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Talsupram | 21489-20-3 – ChemicalBook
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Talsupram 21489-20-3 | MedChemExpress
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Talsupram|CAS 21400-58-8|DC Chemicals
Talsupram is a selective noradrenaline inhibitor that has a high affinity for the noradrenaline transporter. Talsupram exhibits anti …
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Talsupram | 21489-20-3
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Buy Talsupram (EVT-431337) | 21489-20-3 – evitachem.com
Talsupram is a chemical compound that has gained attention in pharmacological research, particularly in relation to its potential …
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Cas 21489-20-3,Talsupram | lookchem
The CAS Registry Mumber 21489-20-3 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting …
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Talsupram | norepinephrine reuptake inhibitor | NRI | CAS#21489-20-3 …
Description: WARNING: This product is for research use only, not for human or veterinary use. Talsupram is a selective …
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Talsupram HCl|Selective Norepinephrine Reuptake Inhibitor
Talsupram is a potent, selective NET inhibitor for research. This product is for Research Use Only (RUO). Not for human or …

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