<urn:biopax:UnificationXref:PUBCHEM-COMPOUND_252> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.biopax.org/release/biopax-level3.owl#UnificationXref> .
<urn:biopax:UnificationXref:PUBCHEM-COMPOUND_252> <http://www.biopax.org/release/biopax-level3.owl#db> "PubChem-compound"^^<http://www.w3.org/2001/XMLSchema#string> .
<urn:biopax:UnificationXref:PUBCHEM-COMPOUND_252> <http://www.biopax.org/release/biopax-level3.owl#id> "252"^^<http://www.w3.org/2001/XMLSchema#string> .