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.
Trisporic acids are C-18 terpenoid compounds consisting of (1S)-1,3-dimethyl-4-oxocyclohex-2-ene-1-carboxylic acid which is substituted at position 3 by a (1E-3-methylocta-1,3-dien-1-yl side chain. The double bond at position 3 of the side chain can have E or Z geometry. Position 7 of the side chain may be unsubstituted (trisporic acid A) or substituted by a hydroxy group (trisporic acid B) or an oxo group (trisporic acid C). The trisporic acids are synthesized via beta-carotene and retinol pathways in the Zygomycetes and are pheromone compounds responsible for sexual differentiation in those fungal species.