assertion  retraction  graph  subject          predicate        object           datatype    annotation
1          0           graph  obo:CHEBI_36916  rdfs:label       cation           xsd:string  
1          0           graph  obo:CHEBI_36916  oio:id           CHEBI:36916      xsd:string  
1          0           graph  obo:CHEBI_36916  rdfs:subClassOf  obo:CHEBI_24870  _IRI        
1          0           graph  obo:CHEBI_36916  rdf:type         owl:Class        _IRI