assertion  retraction  graph  subject          predicate        object            datatype    annotation
1          0           graph  obo:CHEBI_33308  rdfs:label       carboxylic ester  xsd:string  
1          0           graph  obo:CHEBI_33308  oio:id           CHEBI:33308       xsd:string  
1          0           graph  obo:CHEBI_33308  rdfs:subClassOf  obo:CHEBI_36586   _IRI        
1          0           graph  obo:CHEBI_33308  rdfs:subClassOf  obo:CHEBI_35701   _IRI        
1          0           graph  obo:CHEBI_33308  rdf:type         owl:Class         _IRI