5-Ureidohydantoin

http://classyfire.wishartlab.com/tax_nodes/C0000000
http://classyfire.wishartlab.com/tax_nodes/C0000002
http://classyfire.wishartlab.com/tax_nodes/C0000436
http://classyfire.wishartlab.com/tax_nodes/C0000078
http://classyfire.wishartlab.com/tax_nodes/C0000078
http://classyfire.wishartlab.com/tax_nodes/C0001231
http://classyfire.wishartlab.com/tax_nodes/C0003633
http://classyfire.wishartlab.com/tax_nodes/C0003152
http://classyfire.wishartlab.com/tax_nodes/C0004139
http://classyfire.wishartlab.com/tax_nodes/C0004557
http://classyfire.wishartlab.com/tax_nodes/C0000323
http://classyfire.wishartlab.com/tax_nodes/C0000117
http://classyfire.wishartlab.com/tax_nodes/C0004150
https://www.ebi.ac.uk/chebi/searchId.do?chebiId=CHEBI:15676
http://metacyc.org/META/new-image?type=COMPOUND&object=S-ALLANTOIN
http://www.hmdb.ca/metabolites/HMDB0000462
http://www.genome.jp/dbget-bin/www_bget?drug:D00121
http://www.genome.jp/dbget-bin/www_bget?cpd:C01551
https://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?sid=347911116
https://www.chemspider.com/Chemical-Structure.199.html
https://mor.nlm.nih.gov/RxNav/search?searchBy=RXCUI&searchTerm=508
https://www.ebi.ac.uk/chebi/searchId.do?chebiId=15676
https://www.ebi.ac.uk/chembldb/index.php/compound/inspect/CHEMBL593429
https://en.wikipedia.org/wiki/Allantoin