assertion  retraction  graph  subject          predicate        object           datatype    annotation
1          0           graph  obo:CHEBI_25213  rdfs:label       metal cation     xsd:string  
1          0           graph  obo:CHEBI_25213  oio:id           CHEBI:25213      xsd:string  
1          0           graph  obo:CHEBI_25213  rdfs:subClassOf  obo:CHEBI_36915  _IRI        
1          0           graph  obo:CHEBI_25213  rdfs:subClassOf  obo:CHEBI_23906  _IRI        
1          0           graph  obo:CHEBI_25213  rdf:type         owl:Class        _IRI