CTB (also known as Cholera Toxin B subunit) is a potent activator of p300 histone acetyltransferase and induces apoptosis in MCF-7 cells.

Physicochemical Properties

Molecular Formula	C16H13NO2F3CL
Molecular Weight	343.728
Exact Mass	343.06
Elemental Analysis	C, 55.91; H, 3.81; Cl, 10.31; F, 16.58; N, 4.07; O, 9.31
CAS #	451491-47-7
PubChem CID	729859
Appearance	White to off-white solid powder
LogP	4.6
Hydrogen Bond Donor Count	1
Hydrogen Bond Acceptor Count	5
Rotatable Bond Count	4
Heavy Atom Count	23
Complexity	405
Defined Atom Stereocenter Count	0
InChi Key	YDXZSNHARVUYNM-UHFFFAOYSA-N
InChi Code	InChI=1S/C16H13ClF3NO2/c1-2-23-14-6-4-3-5-11(14)15(22)21-10-7-8-13(17)12(9-10)16(18,19)20/h3-9H,2H2,1H3,(H,21,22)
Chemical Name	N-[4-chloro-3-(trifluoromethyl)phenyl]-2-ethoxybenzamide
Synonyms	CTB ACT activator; CTB; Histone Acetyltransferase Activator
HS Tariff Code	2934.99.9001
Storage	Powder-20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month Note: This product requires protection from light (avoid light exposure) during transportation and storage.
Shipping Condition	Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Biological Activity

ln Vitro	CTB increases p300 HAT activity in a dose-dependent manner (10, 50, 100, 150, 200, and 250 μM; 10 min) [1]. MCF-7 cells' viability is inhibited by CTB (0 - 200 μM; 24 hours). There is a time-dependent induction of MCF-7 cells by CTB (85.43 μM; 24, 48, and 72 hours) [2]. With an IC50 of 85.43 μM, CTB (50 μM; 24 h) boosts p300/CBP activity[2].
Cell Assay	Cell viability assay [2] Cell Types: MCF-7 Cell Tested Concentrations: 0-200 μM Incubation Duration: 24 hrs (hours) Experimental Results: Inhibits viability with IC50 of 85.43 μM and reduces autophagic corrosion in primary neurons [3]. . Apoptosis analysis [2] Cell Types: MCF-7 Cell Tested Concentrations: 85.43 μM Incubation Duration: 24, 48 and 72 h Experimental Results: Time-dependent apoptosis was induced.
References	[1]. Activation of p300 histone acetyltransferase by small molecules altering enzyme structure: probed by surface-enhanced Raman spectroscopy. J Phys Chem B. 2007;111(17):4527-4534. [2]. The effect of CTB on P53 protein acetylation and consequence apoptosis on MCF-7 and MRC-5 cell lines. Adv Biomed Res. 2013;2:24. Published 2013 Mar 6. [3]. Promoting tau secretion and propagation by hyperactive p300/CBP via autophagy-lysosomal pathway in tauopathy. Mol Neurodegener. 2020;15(1):2. Published 2020 Jan 6.
Additional Infomation	N-[4-chloro-3-(trifluoromethyl)phenyl]-2-ethoxybenzamide is a member of benzamides. An ENTEROTOXIN from VIBRIO CHOLERAE. It consists of two major protomers, the heavy (H) or A subunit and the B protomer which consists of 5 light (L) or B subunits. The catalytic A subunit is proteolytically cleaved into fragments A1 and A2. The A1 fragment is a MONO(ADP-RIBOSE) TRANSFERASE. The B protomer binds cholera toxin to intestinal epithelial cells and facilitates the uptake of the A1 fragment. The A1 catalyzed transfer of ADP-RIBOSE to the alpha subunits of heterotrimeric G PROTEINS activates the production of CYCLIC AMP. Increased levels of cyclic AMP are thought to modulate release of fluid and electrolytes from intestinal crypt cells.

Solubility Data

Solubility (In Vitro)

DMSO : ~100 mg/mL (~290.93 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 2.5 mg/mL (7.27 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL. Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution. Solubility in Formulation 2: ≥ 2.5 mg/mL (7.27 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	2.9093 mL	14.5463 mL	29.0926 mL
	5 mM	0.5819 mL	2.9093 mL	5.8185 mL
	10 mM	0.2909 mL	1.4546 mL	2.9093 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.