Description
Summary Abstract
(−)-BPAP (R-(−)-1-(benzofuran-2-yl)-2-propylaminopentane; benzofuranylpropylaminopentane; CAS 260550-89-8) is a selective tryptamine-derived synthetic catecholaminergic/serotoninergic activity enhancer (CAE/SAE) developed by Knoll and colleagues as a successor to (−)-deprenyl (selegiline). At subnanomolar to picomolar concentrations it potentiates impulse-propagation-mediated exocytosis of dopamine, norepinephrine, and serotonin from mesencephalic neurons without depleting transmitter stores or directly occupying monoamine receptors. Its primary molecular target is vesicular monoamine transporter-2 (VMAT2), through which it exerts a highly characteristic bimodal, bell-shaped concentration–effect curve. Preclinical studies support neuroprotective activity against beta-amyloid toxicity, cognitive enhancement in tetrabenazine-inhibited paradigms, and a longevity-associated reduction of spontaneous tumor incidence in rats.
Clinical Indications
Preclinical evidence supports (−)-BPAP as a tool compound for studying monoaminergic enhancement across several neurological research contexts:
- Neurodegenerative Disease Models: Demonstrated neuroprotection of hippocampal neurons from beta-amyloid toxicity at 10⁻¹⁴ M concentration, supporting Alzheimer’s disease pathway research.
- Depression and Mood Circuitry: Reverses tetrabenazine-induced inhibition of active avoidance performance approximately 130-fold more potently than (−)-deprenyl in shuttle-box paradigms, informing monoamine-deficiency models of depression.
- Parkinsonian Models: Reverses reserpine-induced hypolocomotion and exerts l-DOPA-sparing effects in dopamine-depletion models, providing a mechanistic tool for nigrostriatal pathway studies.
Contraindications
- MAO Inhibitor Co-administration: Concurrent use with non-selective monoamine oxidase (MAO) inhibitors may amplify monoaminergic surges; appropriate in vivo study design should account for MAO-B status.
- High-Dose Convulsive Threshold: Beta-phenylethylamine derivatives at suprapharmacological doses suppress M-currents and leakage K⁺ currents in cortical neurons, reducing the threshold for neuronal hyperexcitability in preclinical models.
- Pregnancy / Developmental Models: Early-life bisphenol AP (BPAP, a structurally distinct bisphenol congener) research should not be conflated with (−)-BPAP pharmacology; species and developmental-stage controls are essential in any in vivo design.
Mechanism of Action (MOA)
The enhancer effect of (−)-BPAP operates through a discrete mechanism distinct from classical monoamine reuptake inhibition or MAO inhibition:
VMAT2 Interaction
Interaction with distinct sites on vesicular monoamine transporter-2 (VMAT2) is the principal mechanism underlying the characteristic bimodal bell-shaped dose-response curve. At femtomolar-to-picomolar concentrations, this yields the specific enhancer effect, selectively amplifying impulse-propagation-dependent exocytosis.
Tryptamine-Derived Selectivity
(−)-BPAP originates from a tryptamine scaffold, conferring activity at serotonergic neurons in addition to catecholaminergic neurons—a key distinction from the phenylethylamine-derived (−)-deprenyl, which is nearly inactive on serotonin systems. At 36 nM it significantly enhances stimulated [³H]-serotonin release from isolated rat brain stem.
High-Concentration Reuptake Inhibition
At micromolar concentrations, (−)-BPAP transitions to a non-specific enhancer mode with measurable dopamine transporter (DAT) inhibition (IC₅₀ ≈ 42 nM—approximately 12-fold more potent than cocaine in DAT uptake assays). This concentration dependency is pharmacologically relevant for distinguishing enhancer-specific from transporter-mediated effects in experimental designs.
Neuroprotective Signaling
Cytoprotective effects on human brain capillary endothelial cells (HBECs) and rat PC12 cells have been demonstrated at femtomolar-to-picomolar concentrations, confirming both cell types as enhancer-sensitive. The compound also attenuated methamphetamine-seeking reinstatement in rodent models, indicating broader mesolimbic circuit modulation.
Key Features & Specifications
(−)-BPAP is supplied as a liquid solution suited for in vivo and in vitro monoaminergic enhancement studies:
Chemical Analysis
| Property | Specification Reference Data |
|---|---|
| IUPAC Name | (2R)-1-(1-Benzofuran-2-yl)-N-propylpentan-2-amine |
| CAS Number | 260550-89-8 |
| Molecular Formula | C16H23NO |
| Molecular Weight | 245.36 g/mol |
| PubChem CID | 9816303 |
| Synonyms | R-(−)-BPAP; benzofuranylpropylaminopentane; (−)-BPAP; 1-(benzofuran-2-yl)-2-propylaminopentane |
| Form / Variation | Liquid Solution (SKU L-024, $48.00) |
Storage, Safety, and Handling
Storage Protocol
Store liquid solution at 2–8 °C protected from light; for long-term archival, −20 °C is preferred. Avoid repeated freeze-thaw cycles. Confirm container integrity before each use, as benzofuran-containing amines may be sensitive to oxidative degradation upon prolonged air exposure.
Handling & Compliance
Handle with standard laboratory personal protective equipment (PPE) including nitrile gloves, safety eyewear, and lab coat. (−)-BPAP is not an approved pharmaceutical in any jurisdiction. It is listed by the World Anti-Doping Agency (WADA) under the category of non-approved substances; institutional compliance review is advisable for any in vivo study design.