assertion  retraction  graph  subject          predicate        object                  datatype    annotation
1          0           graph  obo:CHEBI_27933  rdfs:label       beta-lactam antibiotic  xsd:string  
1          0           graph  obo:CHEBI_27933  oio:id           CHEBI:27933             xsd:string  
1          0           graph  obo:CHEBI_27933  rdfs:subClassOf  obo:CHEBI_35627         _IRI        
1          0           graph  obo:CHEBI_27933  rdfs:subClassOf  obo:CHEBI_25558         _IRI        
1          0           graph  obo:CHEBI_27933  rdf:type         owl:Class               _IRI