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.
Any biogenic substance that has undergone transformation through the action of geological processes. Thus the term does not include compounds produced entirely by biological processes, such as shells of marine molluscs, oxalate crystals in plant tissues, etc., but does include the constituents of limestones and phosphorites derived from marine organisms.