Β-Chlornaltrexamine

β-Chlornaltrexamine (β-CNA) is a non-selective irreversible antagonist of the μ-opioid receptor (MOR), the δ-opioid receptor (DOR), and the κ-opioid receptor (KOR), which forms a covalent bond to the binding sites of these receptors and has ultra-long-lasting opioid antagonist effects.^[1] Although it is predominantly antagonistic, β-CNA also shows some irreversible mixed agonist–antagonist activity at the MOR and KOR and some associated analgesic effects.^[2][3] Its alkylating group is a bis(chloroalkyl)amino-residue similar to that of the nitrogen mustards.^[4][5][6][7]

β-Chlornaltrexamine

Clinical data
Other names	β-Chlornaltrexamine; Beta-Chlornaltrexamine; β-CNA; Beta-CNA; Chlornaltrexamine; CNA; 6β-[Bis(2-chloroethyl)amino]-17-(cyclopropylmethyl)-4,5α-epoxymorphinan-3,14-diol
Identifiers
IUPAC name (4R,4aS,7R,7aR,12bS)-7-[bis(2-chloroethyl)amino]-3-(cyclopropylmethyl)-1,2,4,5,6,7,7a,13-octahydro-4,12-methanobenzofuro[3,2-e]isoquinoline-4a,9-diol
CAS Number	67025-94-9 Y
PubChem CID	5486190
ChemSpider	4588895 Y
ChEMBL	ChEMBL3228678
CompTox Dashboard (EPA)	DTXSID90985877
Chemical and physical data
Formula	C24H32Cl2N2O3
Molar mass	467.43 g·mol−1
3D model (JSmol)	Interactive image
SMILES C1C[C@]2([C@H]3CC4=C5[C@@]2(CCN3CC6CC6)[C@H]([C@@H]1N(CCCl)CCCl)OC5=C(C=C4)O)O
InChI InChI=1S/C24H32Cl2N2O3/c25-8-11-27(12-9-26)17-5-6-24(30)19-13-16-3-4-18(29)21-20(16)23(24,22(17)31-21)7-10-28(19)14-15-1-2-15/h3-4,15,17,19,22,29-30H,1-2,5-14H2/t17-,19-,22+,23+,24-/m1/s1 Key:OSLQQDMGHVQLCH-HRMPSQMFSA-N
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The drug was first described by 1978.^[8][9] It should not be confused with its epimer and related drug α-chlornaltrexamine (α-CNA), which is likewise predominantly an irreversible antagonist of the opioid receptors but also shows some irreversible mixed agonist–antagonist activity.^[10]

See also

• Naltrexamine, an opioid receptor antagonist and the parent compound
• β-Funaltrexamine, a related irreversible opioid receptor antagonist
• Naloxazone, an irreversible μ-opioid receptor antagonist
• Methocinnamox, an irreversible μ-opioid receptor antagonist
• Chloroxymorphamine, an irreversible opioid receptor agonist
• Oxymorphazone, an irreversible opioid receptor agonist