70 research outputs found
Diels-Alder Adducts of Morphinan-6,8-Dienes and Their Transformations.
6,14-ethenomorphinans are semisynthetic opiate derivatives containing an ethylene bridge between positions 6 and 14 in ring-C of the morphine skeleton that imparts a rigid molecular structure. These compounds represent an important family of opioid receptor ligands in which the 6,14-etheno bridged structural motif originates from a [4 + 2] cycloaddition of morphinan-6,8-dienes with dienophiles. Certain 6,14-ethenomorphinans having extremely high affinity for opioid receptors are often non-selective for opioid receptor subtypes, but this view is now undergoing some revision. The agonist 20R-etorphine and 20R-dihydroetorphine are several thousand times more potent analgesics than morphine, whereas diprenorphine is a high-affinity non-selective antagonist. The partial agonist buprenorphine is used as an analgesic in the management of post-operative pain or in substitution therapy for opiate addiction, sometimes in combination with the non-selective antagonist naloxone. In the context of the current opioid crisis, we communicated a summary of several decades of work toward generating opioid analgesics with lesser side effects or abuse potential. Our summary placed a focus on Diels-Alder reactions of morphinan-6,8-dienes and subsequent transformations of the cycloadducts. We also summarized the pharmacological aspects of radiolabeled 6,14-ethenomorphinans used in molecular imaging of opioid receptors
Optimization of a Nucleophilic Two-Step Radiosynthesis of 6-O-(2-[18F]fluoroethyl)-6-O-desmethyl-diprenorphine ([18F]FE-DPN) for PET Imaging of Brain Opioid Receptors.
We have established a method for nucleophilic one-pot, two-step radiosynthesis of the popular opioid receptor radioligand 6-O-(2-[18F]fluoroethyl)-6-O-desmethyl-diprenorphine ([18F]FE-DPN) from the novel precursor 6-O-(2-tosyloxyethyl)-6-O-desmethyl- 3-O-trityl-diprenorphine (TE-TDDPN), which we designate as the Henriksen precursor. We undertook an optimization of the synthesis conditions, aiming to enhance the accessibility of [18F]FE-DPN for positron emission tomography (PET) studies of μ-opioid receptors. Herein, we report an optimized direct nucleophilic 18F-fluorination and the deprotection conditions for a fully automated radiosynthesis of [18F]FE-DPN on a modified GE Tracerlab FX FE synthesis panel. Starting from 1-1.5 GBq of [18F]fluoride and applying an Oasis Max 1cc cartridge for fluorine-18 trapping with a reduced amount of K2CO3 (5.06 μmol K+ ion), [18F]FE-DPN ([18F]11) was produced with 44.5 ± 10.6 RCY (decay-corrected), high radiochemical purity (>99%), and a molar activity of 32.2 ± 11.8 GBq/μmol in 60-65 min
Kalcium és foszfát ionok in vitro csontokba juttatása, valamint azok vizsgálata színkép analitikai módszerekkel
Kalcium és Foszfát ionok in vitro csontokba juttatása iontoforetikus módszerrel, valamint azok analízise atomabszorpciós, valamint ICP-OES módszerekkel.BSc/BAKémiag
Elvi kérdések perrendtartásunk bizonyítási rendszerében
Dezső Gyula és Bacsó Jenő bírálatávalFélold. gépírá
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