Alfentanyl

https://www.ebi.ac.uk/chebi/searchId.do?chebiId=CHEBI:2569
http://www.hmdb.ca/metabolites/HMDB0014940
http://www.genome.jp/dbget-bin/www_bget?drug:D07122
http://www.genome.jp/dbget-bin/www_bget?cpd:C08005
https://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=51263
https://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?sid=46505618
https://www.chemspider.com/Chemical-Structure.46451.html
http://www.bindingdb.org/bind/chemsearch/marvin/MolStructure.jsp?monomerid=83450
https://mor.nlm.nih.gov/RxNav/search?searchBy=RXCUI&searchTerm=480
https://www.ebi.ac.uk/chebi/searchId.do?chebiId=2569
https://www.ebi.ac.uk/chembldb/index.php/compound/inspect/CHEMBL634
https://zinc.docking.org/substances/ZINC000000601281
http://bidd.nus.edu.sg/group/cjttd/ZFTTDDRUG.asp?ID=DAP001134
http://www.pharmgkb.org/drug/PA448084
http://www.rxlist.com/cgi/generic2/alfent.htm
https://en.wikipedia.org/wiki/Alfentanil