assertion  retraction  graph  subject          predicate        object           datatype  annotation
1          0           graph  obo:CHEBI_25409  rdfs:subClassOf  obo:CHEBI_26873  _IRI      
1          0           graph  obo:CHEBI_26658  rdfs:subClassOf  obo:CHEBI_26873  _IRI      
1          0           graph  obo:CHEBI_37668  rdfs:subClassOf  obo:CHEBI_26873  _IRI