The Chemical Entities of Biological Interest (ChEBI) ontology is downloaded weekly from EMBL-EBI at http://www.ebi.ac.uk/chebi/. The data is made available under the Creative Commons License (CC BY 3.0, http://creativecommons.org/licenses/by/3.0/). For more information see: Degtyarenko et al. (2008) ChEBI: a database and ontology for chemical entities of biological interest. Nucleic Acids Res. 36, D344–D350.
A pyrazolone that is 5-methyl-4-methylene-2-(p-carboxyphenyl)-2,4-dihydro-3H-pyrazol-3-one in which the exocyclic carbon of the methylene group is attached to a 5-(4,5-dimethyl-2-nitrophenyl)furan-2-yl group by a single bond. C646 is a potent, cell permeable and selective competitive inhibitor of p300 and CBP (p300/CBP) histone acetyltransferases.