Proline

http://www.hmdb.ca/metabolites/HMDB0014332
http://www.genome.jp/dbget-bin/www_bget?drug:D00365
https://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=3958
https://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?sid=46508468
https://www.chemspider.com/Chemical-Structure.3821.html
http://www.bindingdb.org/bind/chemsearch/marvin/MolStructure.jsp?monomerid=50292627
https://mor.nlm.nih.gov/RxNav/search?searchBy=RXCUI&searchTerm=6470
https://www.ebi.ac.uk/chebi/searchId.do?chebiId=6539
https://www.ebi.ac.uk/chembldb/index.php/compound/inspect/CHEMBL580
http://bidd.nus.edu.sg/group/cjttd/ZFTTDDRUG.asp?ID=DAP000237
http://www.pharmgkb.org/drug/PA450267
http://www.rxlist.com/cgi/generic/loraz.htm
https://www.drugs.com/lorazepam.html
https://en.wikipedia.org/wiki/Lorazepam