IBNtxA

IBNtxA, or 3-iodobenzoyl naltrexamine, is an atypical opioid analgesic drug derived from naltrexone. In animal studies it produces potent analgesic effects that are blocked by levallorphan^[1] and so appear to be μ-opioid mediated, but it fails to produce constipation or respiratory depression, and is neither rewarding or aversive^[2] in conditioned place preference protocols.^[3] These unusual properties are thought to result from agonist action at a splice variant or heterodimer of the μ-opioid receptor,^[4] rather than at the classical full length form targeted by conventional opioid drugs.^[5]

IBNtxA

Clinical data
ATC code	none
Identifiers
IUPAC name N-[(4R,4aS,7R,7aR,12bS)-3-(cyclopropylmethyl)-4a,9-dihydroxy-1,2,4,5,6,7,7a,13-octahydro-4,12-methanobenzofuro[3,2-e]isoquinoline-7-yl]-3-iodobenzamide
CAS Number	1314879-44-1 Y
PubChem CID	51003467
ChemSpider	26617995
ChEMBL	ChEMBL1795711
CompTox Dashboard (EPA)	DTXSID201018246
Chemical and physical data
Formula	C27H29IN2O4
Molar mass	572.443 g·mol−1
3D model (JSmol)	Interactive image
SMILES C1C[C@]2([C@H]3CC4=C5[C@@]2(CCN3CC6CC6)[C@H]([C@@H]1NC(=O)C7=CC(=CC=C7)I)OC5=C(C=C4)O)O
InChI InChI=1S/C27H29IN2O4/c28-18-3-1-2-17(12-18)25(32)29-19-8-9-27(33)21-13-16-6-7-20(31)23-22(16)26(27,24(19)34-23)10-11-30(21)14-15-4-5-15/h1-3,6-7,12,15,19,21,24,31,33H,4-5,8-11,13-14H2,(H,29,32)/t19-,21-,24+,26+,27-/m1/s1 Key:FGAFDGWRFOJPRY-XGTKUTNFSA-N

In the Radioligand binding assay it has shown to have affinities of 0.11nM at the MOR, 0.24nM at the DOR and 0.03nM at the KOR and in the Hot- Plate Assay it is shown to be around 20x more potent than morphine. Azido Aryl Analogues of IBNtxA retain significant activity at the MOR.^[6]