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 organic heterotetracyclic compound that consists of 4,5,5a,9c-tetrahydro-3H-2a,9b-diazacyclopenta[jk]fluorene-1,3(2H)-dione substituted by a hydroxy group at position 5, a methyl group at position 2 and a 4-oxoquinazolin-3(4H)-yl group at position 4 (the 2S,4R,5aS,9cS stereoisomer). It is a cytotoxic alkaloid isolated from the endophytic fungus Chaetomium.