C 646

Pricing Availability   Qty
Description: p300/CBP inhibitor
Chemical Name: 4-[4-[[5-(4,5-Dimethyl-2-nitrophenyl)-2-furanyl]methylene]-4,5-dihydro-3-methyl-5-oxo-1H-pyrazol-1-yl]benzoic acid
Purity: ≥98% (HPLC)
Citations (2)
Reviews (1)
Literature (1)

Biological Activity for C 646

C 646 is a p300/CREB-binding protein (CBP) inhibitor (Ki = 400 nM). Suppresses histone H3 and H4 acetylation in mouse fibroblast cell lines. Also represses pluripotency markers in mouse embryonic stem cells. Newer p300 probes are also available: iP300w (Cat. No. 7270) and A 485 (Cat. No. 6387).

This compound is a mixture of Z:E isomers (~ 80:20).

Technical Data for C 646

M. Wt 445.42
Formula C24H19N3O6
Storage Store at +4°C
Purity ≥98% (HPLC)
CAS Number 328968-36-1
PubChem ID 1285941
Smiles CC/2=NN(C(C2=C/C3=CC=C(C4=CC(C)=C(C)C=C4[N+]([O-])=O)O3)=O)C1=CC=C(C(O)=O)C=C1

The technical data provided above is for guidance only. For batch specific data refer to the Certificate of Analysis.

Tocris products are intended for laboratory research use only, unless stated otherwise.

Solubility Data for C 646

Solvent Max Conc. mg/mL Max Conc. mM
DMSO 11.14 25

Preparing Stock Solutions for C 646

The following data is based on the product molecular weight 445.42. Batch specific molecular weights may vary from batch to batch due to the degree of hydration, which will affect the solvent volumes required to prepare stock solutions.

Select a batch to recalculate based on the batch molecular weight:
Concentration / Solvent Volume / Mass 1 mg 5 mg 10 mg
0.25 mM 8.98 mL 44.9 mL 89.8 mL
1.25 mM 1.8 mL 8.98 mL 17.96 mL
2.5 mM 0.9 mL 4.49 mL 8.98 mL
12.5 mM 0.18 mL 0.9 mL 1.8 mL

Molarity Calculator

Calculate the mass, volume, or concentration required for a solution.

*When preparing stock solutions always use the batch-specific molecular weight of the product found on the vial label and CoA (available online).

Reconstitution Calculator

The reconstitution calculator allows you to quickly calculate the volume of a reagent to reconstitute your vial. Simply enter the mass of reagent and the target concentration and the calculator will determine the rest.


Dilution Calculator

Calculate the dilution required to prepare a stock solution.

References for C 646

References are publications that support the biological activity of the product.

Bowers et al (2010) Virtual ligand screening of the p300/CBP histone acetyltransferase: identification of a selective small molecule inhibitor. Chem.Biol. 17 471 PMID: 20534345

Mali et al (2010) Butyrate greatly enhances derivation of human induced pluripotent stem cells by promoting epigenetic remodeling and the expression of pluripotency-associated genes. Stem Cells 28 713 PMID: 20201064

Ott and Verdi (2010) HAT trick: p300, small molecule, inhibitor. Chem.Biol. 17 417 PMID: 20534339

Crump et al (2011) Dynamic acetylation of all lysine-4 trimethylated histone H3 is evolutionarily conserved and mediated by p300/CBP. Proc.Natl.Acad.Sci. USA 108 7814

Dan et al (2015) Roles for histone acetylation in regulation of telomere elongation and two-cell state in mouse ES cells. J.Cell.Physiol. 230 2337 PMID: 25752831

Dahlin et al (2017) Assay interference and off-target liabilities of reported histone acetyltransferase inhibitors. Nat.Commun. 8 1527 PMID: 29142305

If you know of a relevant reference for C 646, please let us know.

View Related Products by Product Action

View all Histone Acetyltransferase Inhibitors

Keywords: C 646, C 646 supplier, C646, p300, CREB-binding, proteins, CBP, inhibitors, inhibits, histone, acetyltransferase, hat, kat, posttranslational, modifications, epigenetics, Post-translational, Modifications, Histone, Acetyltransferases, Other, Differentiation, Products, 4200, Tocris Bioscience

2 Citations for C 646

Citations are publications that use Tocris products. Selected citations for C 646 include:

Yi et al (2021) Neuronal activity-induced BRG1 phosphorylation regulates enhancer activation. Cell Rep 36 109357 PMID: 34260936

Dong-Ming et al (2022) Accumulation of pTreg cells is detrimental in late-onset (aged) mouse model of multiple sclerosis. Aging Cell 21 e13630 PMID: 35615905

Do you know of a great paper that uses C 646 from Tocris? Please let us know.

Reviews for C 646

Average Rating: 5 (Based on 1 Review.)

5 Star
4 Star
3 Star
2 Star
1 Star

Have you used C 646?

Submit a review and receive an Amazon gift card.

$50/€35/£30/$50CAN/¥300 Yuan/¥5000 Yen for first to review with an image

$25/€18/£15/$25CAN/¥75 Yuan/¥1250 Yen for a review with an image

$10/€7/£6/$10 CAD/¥70 Yuan/¥1110 Yen for a review without an image

Submit a Review

Filter by:

C 646 In vitro concentration.
By Anonymous on 01/08/2018
Assay Type: In Vitro
Species: Human
Cell Line/Tissue: Intestinal subepithelial myofibroblasts, smooth muscle cells,

It is dissolved well in DMSO. I diluted it with serum free medium (final concentration of 10 micromolar) and treated the cells for different time points to detect its inhibitory effect of p300 at protein level.

Literature in this Area

Tocris offers the following scientific literature in this area to showcase our products. We invite you to request* your copy today!

*Please note that Tocris will only send literature to established scientific business / institute addresses.

Epigenetics Scientific Review

Epigenetics Scientific Review

Written by Susanne Müller-Knapp and Peter J. Brown, this review gives an overview of the development of chemical probes for epigenetic targets, as well as the impact of these tool compounds being made available to the scientific community. In addition, their biological effects are also discussed. Epigenetic compounds available from Tocris are listed.