assertion  retraction  graph  subject          predicate        object           datatype  annotation
1          0           graph  obo:CHEBI_36181  rdfs:subClassOf  obo:CHEBI_33308  _IRI      
1          0           graph  obo:CHEBI_47622  rdfs:subClassOf  obo:CHEBI_33308  _IRI      
1          0           graph  obo:CHEBI_25000  rdfs:subClassOf  obo:CHEBI_33308  _IRI