Comtade

https://www.ebi.ac.uk/chebi/searchId.do?chebiId=CHEBI:4798
http://www.hmdb.ca/metabolites/HMDB0012226
http://www.genome.jp/dbget-bin/www_bget?drug:D00781
http://www.genome.jp/dbget-bin/www_bget?cpd:C07943
https://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=5281081
https://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?sid=46508734
https://www.chemspider.com/Chemical-Structure.4444537.html
http://www.bindingdb.org/bind/chemsearch/marvin/MolStructure.jsp?monomerid=50108879
https://mor.nlm.nih.gov/RxNav/search?searchBy=RXCUI&searchTerm=60307
https://www.ebi.ac.uk/chebi/searchId.do?chebiId=4798
https://www.ebi.ac.uk/chembldb/index.php/compound/inspect/CHEMBL953
https://zinc.docking.org/substances/ZINC000035342787
http://bidd.nus.edu.sg/group/cjttd/ZFTTDDRUG.asp?ID=DAP000608
http://www.pharmgkb.org/drug/PA164748726
https://www.ebi.ac.uk/pdbe-srv/pdbechem/chemicalCompound/show/PD9
http://www.rxlist.com/cgi/generic3/entac.htm
https://www.drugs.com/cdi/entacapone.html
https://en.wikipedia.org/wiki/Entacapone