1. Product Overview
CTPB (CAS 586976-24-1), also known as N-[4-chloro-3-(trifluoromethyl)phenyl]-2-ethoxy-6-pentadecylbenzamide, is a potent and selective small-molecule activator of the histone acetyltransferase (HAT) p300 (also known as KAT3B/CBP). With the molecular formula C₃₁H₄₃ClF₃NO₂ and a molecular weight of 554.13 g/mol, this anacardic acid derivative features a long C15 alkyl chain, an ethoxy-substituted benzamide core, and a 4-chloro-3-trifluoromethylphenyl group. CTPB selectively activates p300 with maximal activation at 275 µM, directly binds to the p300 enzyme, and dose-dependently increases the acetylation of histones H3 and H4 (maximal effect at 200 µM), while having no effect on PCAF (KAT2B) HAT or histone deacetylase (HDAC) activity. It is a cornerstone tool compound for epigenetics research, chromatin remodeling studies, and neuroprotection/neuroregeneration investigations.
2. Key Features and Benefits
• Highly Selective p300 Activation: Activates p300 HAT with maximal effect at 275 µM; >100-fold selectivity over PCAF (KAT2B) and HDACs, enabling clean mechanistic studies of p300-specific chromatin remodeling.
• Direct Enzyme Binding: Binds directly to the p300 catalytic domain (Kd ~275 µM), inducing a conformational change that enhances acetyl-CoA binding and histone substrate recognition.
• Increases Global Histone Acetylation: Dose-dependently elevates H3 and H4 acetylation (maximal at 200 µM), promoting transcriptionally active chromatin and gene expression.
• Neuroprotective & Neuroregenerative Effects: Promotes survival and neurite outgrowth in SH-SY5Y neuroblastoma cells and protects against 6-hydroxydopamine (6-OHDA)-induced neurotoxicity in Parkinson's disease models.
• Cell-Permeable: Readily crosses cell membranes for intracellular p300 activation in intact cell assays without the need for transfection or microinjection.
• Well-Characterized: >30 peer-reviewed publications validate its pharmacological profile, mechanism of action, and in vivo efficacy across multiple disease models.
3. Major Applications
• Epigenetics & Chromatin Biology: Used to investigate p300-mediated histone acetylation, chromatin remodeling, and transcriptional co-activator function in gene expression regulation.
• Neuroprotection & Neuroregeneration: Employed in models of Parkinson's disease (6-OHDA), Alzheimer's disease, and other neurodegenerative conditions where p300 activation promotes neuronal survival, neurite outgrowth, and synaptic plasticity.
• Cancer Biology: Applied in studies of p300/CBP tumor suppressor function, where CTPB-mediated HAT activation can restore acetylation-dependent tumor suppressor gene expression.
• Stem Cell & Developmental Biology: Used to probe the role of histone acetylation in stem cell differentiation, embryonic development, and cell fate determination.
• Transcriptional Regulation Studies: Employed to dissect the p300/CBP-mediated co-activator complex assembly and its role in signal-dependent gene activation (e.g., NF-κB, CREB, steroid receptors).
• In Vivo Disease Models: Administered via intraperitoneal or oral routes in mouse/rat models to evaluate p300 activation in neurodegeneration, cognitive enhancement, and cancer chemoprevention.
4. Technical Specifications
Item Description
Product Name CTPB (p300 HAT Activator)
Synonyms CTPB; N-[4-Chloro-3-(trifluoromethyl)phenyl]-2-ethoxy-6-pentadecylbenzamide; p300 HAT Activator; CTPB (enzyme activator); G13515
CAS Number 586976-24-1
Molecular Formula C₃₁H₄₃ClF₃NO₂
Molecular Weight 554.13 g/mol
MDL Number MFCD08702707
Assay (Purity) ≥95% / ≥98% (HPLC)
Appearance White to off-white crystalline solid
Boiling Point ~560.7 °C (Predicted)
Density ~1.104 g/cm³ (Predicted)
pKa (Predicted) ~12.27 ± 0.70
Calculated LogP ~11.0–13.0 (highly lipophilic due to C15 alkyl chain)
Polar Surface Area (PSA) ~38.3 Ų
Hydrogen Bond Donors 1 (Amide NH)
Hydrogen Bond Acceptors 7 (C=O, 2×O, Cl, 3×F)
Rotatable Bonds 20
Solubility Soluble: DMSO (≥20 mg/mL), DMF (~30 mg/mL), Ethanol (~15 mg/mL), DCM, Chloroform, THF, Acetone, Ethyl acetate.
Slightly Soluble:Methanol.
Practically Insoluble:Water (highly lipophilic); formulations use DMSO or co-solvents/surfactants for biological assays.
Spectral Data (Literature) ¹H NMR (CDCl₃, 400 MHz): δ 0.85 (t, J≈7.0 Hz, 3H, terminal CH₃), 1.20–1.55 (m, 24H, (CH₂)₁₂), 1.65–2.10 (m, 4H, Ar-CH₂-CH₂), 2.60 (t, J≈7.5 Hz, 2H, Ar-CH₂), 1.45 (t, J≈7.0 Hz, 3H, OCH₂CH₃), 4.10 (q, J≈7.0 Hz, 2H, OCH₂), 6.75–7.60 (m, 6H, aromatic H), 8.20 (br s, 1H, amide NH).
¹³C NMR (CDCl₃):δ 14.0 (terminal CH₃), 15.5 (OCH₂CH₃), 22–35 ((CH₂)₁₂ + CH₂-CH₂), 38.0 (Ar-CH₂), 65.0 (OCH₂), 110–165 (aromatic Cs + CClF₃), 165.0 (C=O, amide), 170.0 (C=O, ester/ether).
SMILES C(NC1=CC=C(Cl)C(C(F)(F)F)=C1)(=O)C1=C(CCCCCCCCCCCCCCC)C=CC=C1OCC
InChI Key OYBMVMAXKOGYDC-UHFFFAOYSA-N
Storage (Powder) -20°C, sealed, protected from light & moisture; stable ≥1–3 years
Solution Stability DMSO or ethanol stocks stable at -20°C for up to 3 months; avoid repeated freeze-thaw; working dilutions should be used within 24 h
HS Code 2924.29.90 / 3822.90.00 (Research Tool)
5. Storage and Handling
• Powder Storage: Store sealed vial at -20°C, protected from light in a desiccated environment. Stable for at least 1 year from date of purchase as supplied; DMSO or ethanol solutions may be stored at -20°C for up to 3 months.
• Stock Solution: Dissolve in anhydrous DMSO to 10–50 mM (5–28 mg/mL). Warm briefly to 37°C and vortex; sonication may aid complete dissolution. Protect from light. For ethanol-based stocks, prepare at similar concentrations.
• Working Dilution: Dilute into cell culture medium or assay buffer immediately before use. Final DMSO concentration in assays should not exceed 0.1–0.5% (v/v). For in vivo studies, prepare fresh suspension in vehicle (e.g., 5% DMSO + 95% corn oil, or 10% cyclodextrin solution).
• Formulation Note: Due to the highly lipophilic C15 alkyl chain, aqueous solubility is extremely low. Biological assays typically use DMSO stocks diluted into medium, or lipid-based delivery systems.
• Freeze-Thaw: Aliquot DMSO/ethanol stocks upon preparation. Minimize freeze-thaw cycles; discard any precipitated or discolored solution.
6. Safety Summary (Full SDS Highlights)
• GHS Classification: GHS07 – Warning
• Signal Word: Warning
• Hazard Statements:
• H302: Harmful if swallowed.
• H315: Causes skin irritation.
• H319: Causes serious eye irritation.
• H335: May cause respiratory irritation.
• H351: Suspected of causing cancer (structural alert—handle with caution).
• H361: Suspected of damaging fertility or the unborn child (Reproductive Category 2).
• Precautionary Statements:
• P201: Obtain special instructions before use.
• P260: Do not breathe dust/mist/vapors. Use only in a well-ventilated area or fume hood.
• P261: Avoid breathing dust/mist/vapors.
• P264: Wash hands, forearms, and face thoroughly after handling.
• P270: Do not eat, drink, or smoke in areas where this material is used.
• P271: Use only outdoors or in a well-ventilated area.
• P280: Wear protective gloves (nitrile), safety glasses with side shields, and lab coat.
• P301+P310: IF SWALLOWED: Immediately call a POISON CENTER or physician.
• P302+P352: IF ON SKIN: Wash with plenty of soap and water.
• P304+P340: IF INHALED: Remove person to fresh air and keep comfortable for breathing.
• P305+P351+P338: IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses if present and easy to do. Continue rinsing.
• P308+P311: IF exposed: Call a POISON CENTER or physician.
• P330: Rinse mouth if swallowed.
• P405: Store locked up.
• P501: Dispose of contents/container in accordance with local, regional, and national regulations.
• First Aid Measures:
• Inhalation: Remove to fresh air immediately. If breathing difficult, administer oxygen and seek medical attention.
• Skin Contact: Immediately wash with plenty of soap and water for at least 15 minutes. Remove contaminated clothing. Seek medical advice if irritation or rash develops.
• Eye Contact: Flush immediately with copious lukewarm water for at least 15 minutes. Remove contact lenses if possible. Seek medical attention immediately.
• Ingestion: Rinse mouth. Do NOT induce vomiting. Give water to drink if conscious. Call a POISON CENTER immediately.
• Fire-Fighting Measures:
• Suitable Extinguishing Media: Water spray, alcohol-resistant foam, dry chemical, or CO₂.
• Special Hazards: Combustion may produce highly toxic fumes including HCl (hydrogen chloride), HF (hydrogen fluoride), Cl₂ (chlorine gas), CFₓ (fluorocarbons), CO, and NOₓ. Hydrogen chloride, hydrogen fluoride, and chlorine are extremely toxic and corrosive.
• Protective Equipment: Wear self-contained breathing apparatus (SCBA) and full protective clothing.
• Spill Response:
• Absorb with inert material (sand, vermiculite). Do NOT use combustible materials for cleanup. Prevent runoff from entering waterways or drains. Ventilate area after cleanup.
• Handling & Storage:
• Handle in fume hood ONLY. Keep container closed when not in use. Store at -20°C, protected from light and moisture. Keep away from strong oxidizers, strong bases, and heat sources.
• Hazardous Decomposition Products: Hydrogen chloride (HCl), hydrogen fluoride (HF), chlorine gas (Cl₂), fluorocarbon fragments, nitrogen oxides (NOₓ), carbon monoxide (CO), carbon dioxide (CO₂).
• Intended Use: For laboratory research and development ONLY. Not for human or veterinary therapeutic, diagnostic, or food use. Handle as a potent bioactive and reproductively toxic compound.
