assertion  retraction  graph  subject          predicate        object           datatype    annotation
1          0           graph  obo:CHEBI_26421  rdfs:label       pyridines        xsd:string  
1          0           graph  obo:CHEBI_26421  oio:id           CHEBI:26421      xsd:string  
1          0           graph  obo:CHEBI_26421  rdfs:subClassOf  obo:CHEBI_38101  _IRI        
1          0           graph  obo:CHEBI_26421  rdfs:subClassOf  obo:CHEBI_25693  _IRI        
1          0           graph  obo:CHEBI_26421  rdf:type         owl:Class        _IRI