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.
Members of the class of triterpenoid, mostly isolated as bitter principles of the Simaroubaceae family. They are chemically regarded as degraded triterpenes and can be categorized into groups with C18, C19, C20, C22 and C25 skeletons.