Tonpen

https://www.ebi.ac.uk/chebi/searchId.do?chebiId=CHEBI:64318
http://www.hmdb.ca/metabolites/HMDB0014834
http://www.genome.jp/dbget-bin/www_bget?drug:D07906
http://www.genome.jp/dbget-bin/www_bget?cpd:C07544
https://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=8223
https://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?sid=46507632
https://www.chemspider.com/Chemical-Structure.7930.html
http://www.bindingdb.org/bind/chemsearch/marvin/MolStructure.jsp?monomerid=50027065
https://mor.nlm.nih.gov/RxNav/search?searchBy=RXCUI&searchTerm=4025
https://www.ebi.ac.uk/chebi/searchId.do?chebiId=64318
https://www.ebi.ac.uk/chembldb/index.php/compound/inspect/CHEMBL442
https://zinc.docking.org/substances/ZINC000052955754
http://bidd.nus.edu.sg/group/cjttd/ZFTTDDRUG.asp?ID=DAP000141
http://www.pharmgkb.org/drug/PA164747651
https://www.ebi.ac.uk/pdbe-srv/pdbechem/chemicalCompound/show/ERM
http://www.rxlist.com/cgi/generic2/ergotamine.htm
https://www.drugs.com/cdi/ergotamine.html
http://www.pdrhealth.com/drug_info/rxdrugprofiles/drugs/caf1060.shtml
https://en.wikipedia.org/wiki/Ergotamine