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 one of a class of di- or tri-block copolymers with a structure consisting of a primary amino group attached to each end of a polyether backbone based on blocks of butylene oxide, propylene oxide or both propylene oxide and ethylene oxide. Molecular weights are typically of the order of 200-4000. The compounds are used in protein crystallisation.