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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
15
|
| pubmed:dateCreated |
1992-9-4
|
| pubmed:abstractText |
The epimeric 6 beta- and 6 alpha-iodo-3,14-dihydroxy-17-(cyclopropylmethyl)-4,5 alpha-epoxymorphinans (1, ioxy) and (2, epioxy), respectively, were each synthesized in five steps starting with naltrexone. The configuration of the 6-iodo group of 1 was unequivocally determined to be beta-based on single crystal X-ray analysis of its precursor 3-acetoxy-6 beta-iodo-14-hydroxy-17-(cyclopropylmethyl)-4,5 alpha-epoxymorphinan (10). Both 1 and 2 as well as their corresponding 3-O-acetates 10 and 11 were found to readily cross the blood-brain barrier and completely reverse the analgesic effects of a 10 mg/kg intraperitoneal dose of morphine sulfate as determined by the paw withdrawal latency test. Compounds 1 and 2 were found to bind with high affinity to mu, delta, and kappa receptors in vitro. In general, 1 and 2 exhibited higher affinity for mu and kappa receptors than naltrexone while the 6 beta-iodo epimer 1 (ioxy) was more potent than its epimer 2. In a comparison of the 6 beta-halogen substituent on binding affinity across opioid receptor subtypes, it was generally found that I greater than Br greater than F. On the basis of the results of in vitro and in vivo testing, 1 was selected as a target for radioiodination and evaluation as a potential single photon emission computed tomography imaging agent for opioid receptors. Carrier-free [125I]-1 was synthesized in near quantitative yield by the sequence of reaction of excess 3-acetoxy-6 alpha-[[(trifluoromethyl)sulfonyl]oxy]-14-hydroxy-17- (cyclopropylmethyl)-4,5 alpha-epoxymorphinan (8) with anhydrous Na125I in dry acetonitrile for 90 min at 76 degrees C followed by deacetylation of the product with 1:1 aqueous ammonia/acetonitrile at 25 degrees C. The potential of [125I]-1 as an in vivo imaging agent for opioid receptors is evaluated and discussed.
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| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical | |
| pubmed:status |
MEDLINE
|
| pubmed:month |
Jul
|
| pubmed:issn |
0022-2623
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:day |
24
|
| pubmed:volume |
35
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
2826-35
|
| pubmed:dateRevised |
2003-11-14
|
| pubmed:meshHeading |
pubmed-meshheading:1322988-Animals,
pubmed-meshheading:1322988-Binding Sites,
pubmed-meshheading:1322988-Blood-Brain Barrier,
pubmed-meshheading:1322988-Brain,
pubmed-meshheading:1322988-Chromatography, High Pressure Liquid,
pubmed-meshheading:1322988-Guinea Pigs,
pubmed-meshheading:1322988-Indicators and Reagents,
pubmed-meshheading:1322988-Iodine Radioisotopes,
pubmed-meshheading:1322988-Male,
pubmed-meshheading:1322988-Molecular Structure,
pubmed-meshheading:1322988-Morphinans,
pubmed-meshheading:1322988-Rats,
pubmed-meshheading:1322988-Rats, Inbred Strains,
pubmed-meshheading:1322988-Receptors, Opioid,
pubmed-meshheading:1322988-Tomography, Emission-Computed, Single-Photon,
pubmed-meshheading:1322988-X-Ray Diffraction
|
| pubmed:year |
1992
|
| pubmed:articleTitle |
Probes for narcotic receptor mediated phenomena. 18. Epimeric 6 alpha- and 6 beta-iodo-3,14-dihydroxy-17-(cyclopropylmethyl)-4,5 alpha-epoxymorphinans as potential ligands for opioid receptor single photon emission computed tomography: synthesis, evaluation, and radiochemistry of [125I]-6 beta-iodo-3,14-dihydroxy-17-(cyclopropylmethyl)-4,5 alpha-epoxymorphinan.
|
| pubmed:affiliation |
Laboratory of Medicinal Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892.
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| pubmed:publicationType |
Journal Article
|