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 oxopurine in which the purine ring is substituted by oxo groups at positions 2, 6, and 8, and the nitrogens at positions 1, 3, and 7 are substituted by methyl groups. It is a metabolite of caffeine.