Apolex

https://www.ebi.ac.uk/chebi/searchId.do?chebiId=CHEBI:3380
http://www.hmdb.ca/metabolites/HMDB0015328
http://www.genome.jp/dbget-bin/www_bget?drug:D00251
https://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=44093
https://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?sid=46506879
https://www.chemspider.com/Chemical-Structure.40130.html
http://www.bindingdb.org/bind/chemsearch/marvin/MolStructure.jsp?monomerid=21642
https://mor.nlm.nih.gov/RxNav/search?searchBy=RXCUI&searchTerm=1998
https://www.ebi.ac.uk/chebi/searchId.do?chebiId=3380
https://www.ebi.ac.uk/chembldb/index.php/compound/inspect/CHEMBL1560
https://zinc.docking.org/substances/ZINC000000057001
http://bidd.nus.edu.sg/group/cjttd/ZFTTDDRUG.asp?ID=DAP000589
http://www.pharmgkb.org/drug/PA448780
https://www.ebi.ac.uk/pdbe-srv/pdbechem/chemicalCompound/show/X8Z
http://www.rxlist.com/cgi/generic/captop.htm
https://www.drugs.com/captopril.html
http://www.pdrhealth.com/drug_info/rxdrugprofiles/drugs/cap1064.shtml
https://en.wikipedia.org/wiki/Captopril