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.
An aryl phosphate that is indoxyl phopshate in which the indole moiety is substituted at positions 4 and 5 by chlorine and bromine, respectively. It is used to test for the presence of an enzyme, alkaline phosphatase, which cleaves the phosphate group to give 5-bromo-4-chloroindoxyl, which immediately dimerises to give an intensely blue product.