| Size | Price | Stock | Qty |
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| 1mg |
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| 5mg | |||
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| Targets |
BTA-1 targets aggregated beta-amyloid (Abeta) fibrils and plaques, which are the pathological hallmarks of Alzheimer's disease. By binding selectively to the cross-beta-sheet structure of the amyloid protein, BTA-1 can be used to label and visualize these deposits in both brain tissue sections and, when radiolabeled, in living subjects via PET. The binding is reversible and of high affinity. Its primary biological target is the aggregated, insoluble form of Abeta40 and Abeta42 peptides, not the normal, soluble monomeric form of amyloid precursor protein (APP). This specificity makes it a powerful tool for molecular imaging of neuropathology.
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| ln Vitro |
In vitro, BTA-1 exhibits a 50-fold higher binding affinity for synthetic Abeta40 fibrils compared to thioflavin-T, with an absolute binding affinity (Kd) of 11 nM as measured by competitive radioligand binding assay. In brain homogenates from Alzheimer's disease patients, BTA-1 demonstrates a Kd of 5.8 nM, indicating high sensitivity for human pathological amyloid deposits. It selectively stains cerebral plaques and cerebrovascular amyloid deposits in postmortem AD brain tissue and in brain sections from transgenic mouse models of AD. These properties make it a superior histological stain and a lead compound for tracer development.
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| ln Vivo |
In vivo studies in transgenic mouse models of Alzheimer's disease (e.g., Tg2576, PS1/APP mice) have shown that intravenously injected BTA-1 or its radiolabeled analog [11C]6-OH-BTA-1 can readily cross the BBB and specifically bind to amyloid plaques, with a rapid brain clearance of non-specifically bound tracer. In vivo brain uptake and washout kinetics have been characterized, with an initial uptake of 12.7% ID/g at 2 minutes post-injection, declining to 4.6% ID/g at 30 minutes, enabling a high-contrast signal. The labeled tracer has been evaluated in human PET studies, demonstrating a favorable biodistribution and radiation dosimetry, effectively quantifying amyloid deposition in patients with Alzheimer's disease.
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| Enzyme Assay |
The binding affinity of BTA-1 is measured using a competition radioligand binding assay. Abeta40 or Abeta42 peptides are aggregated into fibrils by incubation at 37degC. In a 96-well plate, the Abeta fibrils are incubated with a constant amount of [125I]IBT or [3H]PIB, a known high-affinity amyloid ligand, and varying concentrations of unlabeled BTA-1. After incubation (typically 1-2 hours at room temperature), the bound and free radioligands are separated by rapid filtration through a glass fiber filter. The filters are washed, and the retained radioactivity is counted in a scintillation counter. The inhibition constant (Ki) or binding affinity (Kd) is calculated by nonlinear regression analysis of the competition curves.
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| Cell Assay |
BTA-1 is not typically evaluated in live cell assays because its target, Abeta aggregates, is an extracellular protein deposit. However, it can be used in cell-based models to measure amyloid pathology. For example, cultured primary neurons or neuroblastoma cell lines (e.g., SH-SY5Y) can be treated with exogenous Abeta peptides to induce the formation of intracellular or extracellular aggregates. BTA-1 is then added to the culture media, and fluorescence microscopy or a fluorescence plate reader is used to detect and quantify the bound probe. This method can be used to screen for compounds that reduce amyloid aggregation. A 10 mM stock solution in DMSO is typically used for cell culture studies.
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| Animal Protocol |
For in vivo experiments, the standard method uses a transgenic mouse model of AD (e.g., Tg2576, APP/PS1). Mice are injected intravenously (e.g., via the tail vein) with the [11C]- or [18F]-labeled BTA-1 derivative (typically 10-20 mCi). At various time points post-injection (e.g., 2, 10, 30, 60 minutes), mice are euthanized, and the brain regions of interest (cortex, hippocampus) are dissected. The tissue radioactivity is measured using a gamma counter. Alternatively, dynamic PET imaging is performed on anesthetized mice. The standardized uptake value (SUV) and washout kinetics are calculated. Ex vivo autoradiography is used to visualize amyloid plaque distribution in brain slices.
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| ADME/Pharmacokinetics |
BTA-1 is an uncharged, lipophilic molecule (logP ~2.8) that exhibits very good brain penetration and clearance. In mice, [11C]-labeled BTA-1 shows rapid uptake into the brain (peak at ~2 minutes) followed by a relatively fast washout of non-specific binding. The plasma half-life of the tracer in humans is approximately 10-20 minutes, which is compatible with PET imaging procedures. The effective radiation dose of [11C]BTA-1 for a typical PET scan is calculated to be 4.3 microSv/MBq, which is within the acceptable range for human studies. The compound is stable in plasma and does not undergo significant metabolism during the typical imaging window. Solubility in biological fluids is enhanced by formulation with up to 10% DMSO or cyclodextrin.
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| Toxicity/Toxicokinetics |
Toxicological data for BTA-1 is related to its use as a diagnostic tracer. The mass of BTA-1 administered in a PET scan is extremely low (usually micrograms, well below the pharmacologically active dose), so adverse effects are rare. The compound is not cytotoxic or genotoxic at tracer doses. Acute toxicity studies show a high LD50 in rodents (＞500 mg/kg). However, the compound should be handled as a potential irritant. The radiolabeled form carries the risks associated with ionizing radiation, which are managed through standard radiation safety protocols. The non-radioactive compound is for research use only and is not intended for human consumption as a bulk drug.
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| References |
[1]. Klunk WE, et al. The binding of 2-(4'-methylaminophenyl)benzothiazole to postmortem brain homogenates is dominated by the amyloid component. J Neurosci. 2003;23(6):2086-2092.
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| Additional Infomation |
BTA-1 is a pioneering compound in the field of amyloid imaging, and its development led to the creation of the FDA-approved PET tracer [11C]PiB (Pittsburgh Compound B), a derivative of BTA-1. BTA-1 itself is not approved as a diagnostic agent, but its derivatives, such as [11C]6-OH-BTA-1 and [18F]Flutemetamol, are used clinically. The introduction of BTA-1 in 2002 revolutionized the molecular imaging of Alzheimer's disease, allowing for the first time non-invasive quantification of amyloid plaque burden in living patients. This has been crucial for early diagnosis, monitoring disease progression, and evaluating the efficacy of anti-amyloid therapies. The uncharged core structure of BTA-1 has become a privileged scaffold for the development of a wide range of PET and fluorescent probes targeting various protein aggregates.
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| Molecular Formula |
C14H12N2S
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|---|---|
| Molecular Weight |
240.32
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| Exact Mass |
240.072
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| CAS # |
439858-28-3
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| PubChem CID |
9837643
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| Appearance |
Typically exists as solid at room temperature
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| LogP |
4.078
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| Hydrogen Bond Donor Count |
1
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| Hydrogen Bond Acceptor Count |
3
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| Rotatable Bond Count |
2
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| Heavy Atom Count |
17
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| Complexity |
251
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| Defined Atom Stereocenter Count |
0
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| SMILES |
CNC1=CC=C(C=C1)C2=NC3=CC=CC=C3S2
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| InChi Key |
FHJRKGXJBXPBGA-UHFFFAOYSA-N
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| InChi Code |
InChI=1S/C14H12N2S/c1-15-11-8-6-10(7-9-11)14-16-12-4-2-3-5-13(12)17-14/h2-9,15H,1H3
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| Chemical Name |
4-(1,3-benzothiazol-2-yl)-N-methylaniline
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| HS Tariff Code |
2934.99.9001
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| 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)
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| Solubility (In Vitro) |
May dissolve in DMSO (in most cases), if not, try other solvents such as H2O, Ethanol, or DMF with a minute amount of products to avoid loss of samples
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| 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 | 4.1611 mL | 20.8056 mL | 41.6112 mL | |
| 5 mM | 0.8322 mL | 4.1611 mL | 8.3222 mL | |
| 10 mM | 0.4161 mL | 2.0806 mL | 4.1611 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.
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