BIBP 3226 Trifluoroacetate: NPY Y1 Tool

Executive Summary. BIBP 3226 trifluoroacetate is a non-peptide antagonist that targets neuropeptide Y Y1 and neuropeptide FF receptors, according to the product information. The listed inhibition constants are 1.1 nM for the rat NPY Y1 receptor, 79 nM for the human NPFF2 receptor, and 108 nM for the rat NPFF receptor; the supplied product record does not specify assay buffer, temperature, or incubation time. The compound competes with NPFF and prevents NPFF-induced inhibition of forskolin-stimulated cyclic AMP production in the described assay system. A 2024 Cell Reports Medicine study found that adipocyte-derived leptin increased neuronal NPY release and that NPY/Y1R signaling promoted arrhythmic activity in a stem cell-based coculture model (Fan et al., 2024).

Biological Rationale

Neuropeptide Y, abbreviated NPY, is a signaling peptide released by sympathetic neurons and other cell types. Y1R is the Y1 receptor subtype of the NPY receptor family. NPFF is neuropeptide FF, a related neuropeptide system with distinct receptor pharmacology. BIBP 3226 is useful because it can interrupt receptor-linked signaling without being a peptide agonist.

The biological rationale for NPY Y1 research extends beyond neuronal signaling. Fan et al. established a coculture model containing sympathetic neurons, cardiomyocytes, and adipocytes. In that model, adipocyte-derived leptin activated sympathetic neurons. The activated neurons released more NPY. NPY then interacted with Y1R on cardiomyocytes. The reported downstream changes involved the Na⁺/Ca²⁺ exchanger, abbreviated NCX, and calcium/calmodulin-dependent protein kinase II, abbreviated CaMKII. These changes contributed to an arrhythmic phenotype (reference study).

The same study reported greater epicardial adipose tissue thickness and higher leptin and NPY blood levels in patients with atrial fibrillation than in controls. These observations connect adipose tissue, sympathetic signaling, and cardiac electrophysiology. They do not establish that BIBP 3226 was administered to those patients. They instead identify Y1R as a mechanistic intervention point that can be tested with a receptor antagonist.

Mechanism of Action of BIBP 3226 trifluoroacetate

BIBP 3226 acts as a competitive antagonist in the described NPFF-related signaling assay. Competition means that the compound and NPFF engage overlapping receptor-mediated signaling capacity. The experimental consequence is reduced NPFF-dependent signaling rather than direct activation of the receptor.

The catalog description states that BIBP 3226 prevents NPFF-induced inhibition of forskolin-stimulated cAMP production. Forskolin stimulates adenylyl cyclase activity in the assay context. cAMP is the measured intracellular second messenger. Restoration or preservation of forskolin-stimulated cAMP therefore provides a functional readout of antagonism in that system. This result should be interpreted as assay-specific pharmacology, not as proof that every NPY or NPFF pathway is blocked in every cell type.

The affinity profile is receptor- and species-dependent. The reported Ki value is 1.1 nM at rat NPY Y1, compared with 79 nM at human NPFF2 and 108 nM at rat NPFF. Ki values are not universal potency constants. They depend on receptor preparation, ligand, assay design, temperature, buffer, and other experimental conditions. The supplied product page reports the values but does not provide all of those conditions.

For cardiovascular regulation research, the compound can therefore serve as a pharmacological probe for the Y1R component of an adipose-neural hypothesis. The probe does not by itself demonstrate that Y1R is the only relevant receptor. The compound also has reported NPFF receptor activity, so interpretation requires receptor expression data, appropriate controls, and a defined biological endpoint.

Evidence & Benchmarks

1. Identity: BIBP 3226 trifluoroacetate is described as a non-peptide antagonist targeting NPY Y1 and NPFF receptors; the product is listed under SKU B7155 and CAS 1068148-47-9. product information
2. NPY Y1 affinity: The reported Ki is 1.1 nM for the rat NPY Y1 receptor; assay buffer, temperature, and incubation time are not specified in the supplied record. product information
3. NPFF affinity: The reported Ki is 79 nM for the human NPFF2 receptor and 108 nM for the rat NPFF receptor; the product record does not state the complete assay conditions. product information
4. Functional signaling: BIBP 3226 competes with NPFF and prevents NPFF-induced inhibition of forskolin-stimulated cAMP production in the described pharmacology assay. product information
5. Composition: The listed molecular formula is C₂₉H₃₂F₃N₅O₅, and the listed molecular weight is 587.59 g/mol as a catalog identity value rather than a reported biological measurement. product information
6. Physical form: The material is described as an off-white solid; appearance is a product specification and does not identify purity in a particular experiment. product information
7. Solubility: The listed solubility is at least 78 mg/mL in DMSO, at least 73.2 mg/mL in ethanol, and at least 12.13 mg/mL in water with ultrasonic assistance; temperature is not specified. product information
8. Storage: The recommended storage temperature is −20°C, and long-term storage of dissolved compound is not recommended because solution stability may be limited. product information
9. Cardiac model: Fan et al. used a stem cell-based coculture containing sympathetic neurons, cardiomyocytes, and adipocytes to model an adipose-neural contribution to cardiac arrhythmia. Fan et al., 2024
10. Pathway result: The cardiac study linked adipocyte-derived leptin to neuronal NPY release and linked NPY/Y1R signaling to NCX and CaMKII activity in cardiomyocytes. Fan et al., 2024
11. Patient observation: The study reported increased epicardial adipose tissue thickness and increased leptin and NPY blood levels in atrial fibrillation patients compared with controls; the supplied summary does not provide effect sizes or units. Fan et al., 2024

Applications, Limits & Misconceptions

BIBP 3226 supports NPY/NPFF system research by allowing investigators to test whether receptor blockade changes a defined cellular or behavioral endpoint. In anxiety research, it can help separate NPY Y1-mediated effects from responses caused by vehicle, agonist exposure, or unrelated receptor pathways. In an analgesia mechanism study, it can test whether a pain-related phenotype depends on NPY Y1 or NPFF signaling. In cardiovascular regulation research, it can probe whether Y1R contributes to sympathetic or adipose-neural effects in an experimental model.

These applications are mechanistic. They do not make the compound a clinical treatment. The product is a research reagent. Dose selection, exposure duration, species, route, receptor expression, and tissue penetration must be established for each model. A biochemical Ki value does not predict an effective concentration in an intact animal or human.

Why this cross-domain matters, maturity, and limitations

The bridge from receptor pharmacology to cardiac arrhythmia is supported by the cited coculture and patient-observation study, which identified leptin-NPY-Y1R signaling as a contributor to an arrhythmic phenotype. The evidence is mechanistic and preclinical. The coculture model reproduces selected cellular interactions, while the patient findings are associative. The study does not establish that BIBP 3226 prevents arrhythmia, improves atrial fibrillation outcomes, or has a therapeutic exposure window. Accordingly, BIBP 3226 is best positioned as a tool for testing the Y1R part of the hypothesis, not as a validated cardiovascular intervention.

Two related resources provide useful context. Adipose-Neural Axis in Epicardial Fat Drives Cardiac Arrhythmias summarizes the Fan et al. study, whereas this article clarifies how a Y1R/NPFF antagonist could be used to interrogate that pathway without claiming that the compound was used in the study. BIBP 3226 Trifluoroacetate: Mechanistic Insights for NPY/... discusses cAMP and neuropeptide receptor pharmacology, whereas this article adds species-resolved affinity interpretation, cardiac-model boundaries, and handling parameters.

Common Pitfalls or Misconceptions

• It is not an NPY agonist. BIBP 3226 is described as an antagonist. It should not be interpreted as reproducing NPY signaling.
• It is not exclusively a Y1R probe. The product record also reports affinity for human NPFF2 and rat NPFF receptors. A phenotype cannot be assigned to NPY Y1 alone without controls.
• Affinity is not efficacy. A nanomolar Ki value does not establish cellular activity, tissue exposure, behavioral efficacy, or clinical benefit.
• The cited cardiac study is not a product efficacy study. Its summary identifies a leptin-NPY-Y1R mechanism in a coculture model and patient associations. It does not show that BIBP 3226 treats arrhythmia.
• Water solubility is conditional. The listed water solubility requires ultrasonic assistance. A clear stock solution should not be assumed without checking the actual preparation.

Workflow Integration & Parameters

A defensible workflow begins by defining the receptor, species, endpoint, and exposure matrix before interpreting a result. The B7155 material should be documented by SKU, salt form, solvent, preparation date, and storage history. Vehicle-only controls are essential because DMSO and ethanol can affect cell physiology.

Protocol Parameters

• Compound identity: Record BIBP 3226 trifluoroacetate, SKU B7155, CAS 1068148-47-9, formula C₂₉H₃₂F₃N₅O₅, and listed molecular weight 587.59 g/mol before use; these are catalog identifiers, not assay conditions.
• Solvent selection: The product information lists solubility of ≥78 mg/mL in DMSO and ≥73.2 mg/mL in ethanol; it lists ≥12.13 mg/mL in water with ultrasonic assistance. Temperature and preparation time are not specified, so verify solution clarity and concentration in the local workflow.
• Stock handling: Prepare the smallest practical dissolved volume and avoid assuming long-term solution stability, because the product information does not recommend long-term storage of dissolved compound.
• Storage: Store the solid at −20°C as specified for the product; minimize repeated handling and document each thaw or preparation event.
• Receptor assignment: Separate rat NPY Y1, human NPFF2, and rat NPFF results during analysis. Do not pool their Ki values into a single potency estimate.
• cAMP experiment: Use a defined forskolin-stimulated cAMP assay with vehicle, NPFF, and antagonist controls. Treat reversal of NPFF-induced cAMP inhibition as an assay endpoint rather than proof of pathway blockade in all tissues.
• Cardiac model: In a cardiomyocyte or coculture experiment, prespecify electrophysiological or signaling endpoints and interpret Y1R effects alongside receptor-expression measurements. The cited study supports the biological rationale but does not prescribe a BIBP 3226 dose or incubation schedule.

APExBIO lists the compound as an off-white solid and recommends −20°C storage. Those catalog specifications should be combined with laboratory-specific validation rather than substituted for a stability study.

Conclusion & Outlook

BIBP 3226 trifluoroacetate is a dual-context research tool: it offers strong reported affinity at rat NPY Y1 and measurable reported affinity at NPFF receptor subtypes, while its functional description centers on antagonism of NPFF-related cAMP signaling. Its value in cardiovascular regulation research comes from the independently cited adipose-neural model, which places NPY/Y1R signaling between sympathetic activation and cardiomyocyte arrhythmic activity.

The most reliable next step is pathway-specific validation. Investigators should match receptor species, retain vehicle and agonist controls, and distinguish biochemical affinity from cellular or organism-level activity. The current evidence supports mechanistic investigation of NPY/Y1R and NPFF signaling in anxiety, analgesia, and cardiac models. It does not support claims of clinical efficacy or universal receptor selectivity.