kelatorphan kelatorphan kelatorphan is a drug which acts as a powerful and complete inhibitor of nearly all of the enzymes responsible for catabolism of the endogenous enkephalins, including neutral endopeptidase (nep), dipeptidyl peptidase iii (dpp3), aminopeptidase n (apn), and angiotensin-converting enzyme (ace). in mice, with the intracerebroventricular co-administration of a 50 µg dose of kelatorphan (this route is necessary because kelatorphan is incapable of crossing the blood-brain-barrier) hence alongside exogenous enkephalin (ed50 approximately 10 ng), it potentiated the analgesic effects of the latter by 50,000 times. kelatorphan also displays potent antinociceptive effects alone, and does not depress respiration, although at high doses it actually increases it. kelatorphanclinical dataatc codenonelegal statuslegal status in general: non-regulated identifiers iupac name n--l-alanine cas number92175-57-0pubchem cid123982drugbankdb08040chemspider110501unii46bbw2u5d6comptox dashboard (epa)dtxsid90238911 chemical and physical dataformulac14h18n2o5molar mass294.307 g·mol−13d model (jsmol)interactive image smiles o=c(o)(nc(=o)(cc1ccccc1)cc(=o)no)c inchi inchi=1s/c14h18n2o5/c1-9(14(19)20)15-13(18)11(8-12(17)16-21)7-10-5-3-2-4-6-10/h2-6,9,11,21h,7-8h2,1h3,(h,15,18)(h,16,17)(h,19,20)/t9-,11+/m0/s1key:ojcfztvydskxnm-gxsjlcmtsa-n