Semorphone

Semorphone (Mr 2264) is an opiate analogue that is an N-substituted derivative of oxymorphone.

Semorphone

Clinical data
ATC code	none
Identifiers
IUPAC name (5α)-4,5-Epoxy-3,14-dihydroxy-17-(2-methoxyethyl)morphinan-6-one
CAS Number	88939-40-6
PubChem CID	5491906
ChemSpider	4590760^Y
UNII	2HD55617I2
CompTox Dashboard (EPA)	DTXSID00933465
Chemical and physical data
Formula	C19H23NO5
Molar mass	345.395 g·mol^−1
3D model (JSmol)	Interactive image
SMILES O=C4[C@@H]5Oc1c2c(ccc1O)C[C@H]3N(CC[C@]25[C@@]3(O)CC4)CCOC
InChI InChI=1S/C19H23NO5/c1-24-9-8-20-7-6-18-15-11-2-3-12(21)16(15)25-17(18)13(22)4-5-19(18,23)14(20)10-11/h2-3,14,17,21,23H,4-10H2,1H3/t14-,17+,18+,19-/m1/s1^Y Key:PBGIBLLOMGURPS-GRGSLBFTSA-N^Y
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Semorphone is a partial agonist at μ-opioid receptors. It is around twice the potency of morphine, but with a ceiling effect on both analgesia and respiratory depression[1] which means that these effects stop becoming any stronger after a certain maximum dose.

It is not currently used in medicine, and is not a controlled drug, although it might be considered to be a controlled substance analogue of oxymorphone on the grounds of its related chemical structure in some jurisdictions such as the United States, Canada, Australia and New Zealand.

References

1. Behne M, Bremerich D, Heinrich J, Schumacher H, Scherer M (1994). "Respiratory effects and tolerability of Mr 2264 Cl. A new opiate partial agonist in comparison with morphine and placebo". European Journal of Clinical Pharmacology. 46 (4): 301–4. doi:10.1007/BF00194395. PMID 7957512. S2CID 33001046.