Herein, we demonstrate an efficient method for multi-deuterium labelling of pirtobrutinib-a Bruton's tyrosine kinase inhibitor recently approved by the FDA-using a straightforward hydrogen isotope exchange (HIE) reaction. A remarkably high level of deuterium incorporation was achieved using an excess of a Kerr-type iridium catalyst. The key factor in the significant deuterium labelling was the decision to employ a deuterium uniformly labelled solvent, chlorobenzene-d5, at an elevated temperature. Virtually, no d0-d3 species were detected, with only traces of d4-d5 isotopomers (< 5%) observable in the mass spectrum of pirtobrutinib-d8, fulfilling requirements for stable isotope-labelled internal standard. The labelled compound-mainly consisting of isotopomers d6-d9 at 82.4% of the total abundance-was isolated in a high yield (73%) and purity (99%). Noteworthy, fluorine group acting as a directing group was observed for the first time. Significant incorporation of deuterium in ortho-positions, exceeding 87%, was observed. Interestingly, chlorinated solvent used in the HIE reactions was non-specifically deuterated yielding up to 0.42 deuterium per chlorobenzene molecule even at an exceptionally low iridium catalyst loading of 4.17 × 10-2 mol%.
- Klíčová slova
- HIE, SILIS, chlorobenzene labelling, fluorine directing group, hydrogen isotope exchange, pirtobrutinib‐d8, solvent labelling,
- MeSH
- deuterium * chemie MeSH
- izotopové značení * MeSH
- piperidiny chemie MeSH
- pyrimidiny chemie MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- deuterium * MeSH
- piperidiny MeSH
- pyrimidiny MeSH
Kainate receptors play a crucial role in mediating synaptic transmission within the central nervous system. However, the lack of selective pharmacological tool compounds for the GluK3 subunit represents a significant challenge in studying these receptors. Recently presented compound 1 stands out as a potent antagonist of GluK3 receptors, exhibiting nanomolar affinity at GluK3 receptors and strongly inhibiting glutamate-induced currents at homomeric GluK1 and GluK3 receptors in HEK293 cells with Kb values of 65 and 39 nM, respectively. This study presents the synthesis of two potent GluK3-preferring iodine derivatives of compound 1, serving as precursors for radiolabelling. Furthermore, we demonstrate the optimisation of dehalogenation conditions using hydrogen and deuterium, resulting in [2H]-1, and demonstrate the efficient synthesis of the radioligand [3H]-1 with a specific activity of 1.48 TBq/mmol (40.1 Ci/mmol). Radioligand binding studies conducted with [3H]-1 as a radiotracer at GluK1, GluK2, and GluK3 receptors expressed in Sf9 and rat P2 membranes demonstrated its potential applicability for selectively studying native GluK3 receptors in the presence of GluK1 and 2-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor-blocking ligands.
- Klíčová slova
- ionotropic glutamate receptors, quinoxaline‐2,3‐diones, tritium labelling,
- MeSH
- AMPA receptory chemie metabolismus MeSH
- deuterium MeSH
- HEK293 buňky MeSH
- krysa rodu Rattus MeSH
- kyselina glutamová * MeSH
- lidé MeSH
- receptory kyseliny kainové * chemie metabolismus MeSH
- tritium MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- AMPA receptory MeSH
- deuterium MeSH
- kyselina glutamová * MeSH
- receptory kyseliny kainové * MeSH
- tritium MeSH
The synthesis of tritium-labelled glycine transporter 1 inhibitor Org24598 is reported. Because of the instability of the Org24598 skeleton under hydrogenation conditions, a synthetic approach using an in-house prepared tritium-labelled alkylating agent ([3 H]MeI, SA = 26.2 Ci/mmol) was employed. Alternative methods of labelling are discussed.
- Klíčová slova
- COware gas reactor, GlyT1 inhibitor, [3H]Org24598, [3H]fluoxetine, [3H]methyl iodide preparation, [3H]methylation, [3H]thioanisol,
- MeSH
- glycin * farmakologie analogy a deriváty MeSH
- proteiny přenášející glycin přes plazmatickou membránu * MeSH
- radiofarmaka MeSH
- tritium MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- glycin * MeSH
- org 24598 MeSH Prohlížeč
- proteiny přenášející glycin přes plazmatickou membránu * MeSH
- radiofarmaka MeSH
- tritium MeSH
The σ-1 receptor is a non-opioid transmembrane protein involved in various human pathologies including neurodegenerative diseases, inflammation, and cancer. The previously published ligand [18 F]FTC-146 is among the most promising tools for σ-1 molecular imaging by positron emission tomography (PET), with a potential for application in clinical diagnostics and research. However, the published six- or four-step synthesis of the tosyl ester precursor for its radiosynthesis is complicated and time-consuming. Herein, we present a simple one-step precursor synthesis followed by a one-step fluorine-18 labeling procedure that streamlines the preparation of [18 F]FTC-146. Instead of a tosyl-based precursor, we developed a one-step synthesis of the precursor analog AM-16 containing a chloride leaving group for the SN 2 reaction with 18 F-fluoride. 18 F-fluorination of AM-16 led to a moderate decay-corrected radiochemical yield (RCY = 7.5%) with molar activity (Am ) of 45.9 GBq/μmol. Further optimization of this procedure should enable routine radiopharmaceutical production of this promising PET tracer.
- Klíčová slova
- FTC-146, PET, [18F]FTC-146, chloride leaving group, fluorine-18, non-activated, precursor, radiopharmaceutical, radiosynthesis, σ-1 receptor,
- MeSH
- azepiny MeSH
- benzothiazoly MeSH
- lidé MeSH
- pozitronová emisní tomografie * metody MeSH
- radiofarmaka MeSH
- radioizotopy fluoru chemie MeSH
- receptor sigma-1 * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- 6-(3-fluoropropyl)-3-(2-(azepan-1-yl)ethyl)benzo(d)thiazol-2(3H)-one MeSH Prohlížeč
- azepiny MeSH
- benzothiazoly MeSH
- radiofarmaka MeSH
- radioizotopy fluoru MeSH
- receptor sigma-1 * MeSH
Fast and reasonable low-scale (200 nmol) syringe-made synthesis of 15 N-labeled oligonucleotides representing DNA trinucleotide codons is communicated. All codons were prepared by solid-phase controlled pore glass synthesis column technique via the phosphoramidite method. Twenty-four labeled oligonucleotides covering the DNA genetic code alphabet were prepared using commercially available reagents and affordable equipment in a reasonably short period of time, with acceptable yields and purity for direct applications in mass spectrometry.
- Klíčová slova
- 15N-labeled oligonucleotides, low-scale, phosphoramidite synthesis, syringe-made codon synthesis,
- MeSH
- DNA chemie MeSH
- hmotnostní spektrometrie MeSH
- injekční stříkačky * MeSH
- kodon MeSH
- oligonukleotidy * chemie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- DNA MeSH
- kodon MeSH
- oligonukleotidy * MeSH
[3 H]NAAG, N-acetyl-l-aspartyl-l-glutamic acid, has been widely used as a substrate in glutamate carboxypeptidase II (GCPII) reactions, either to determine the inhibitory constants at 50% inhibition (IC50 ) of novel compounds or to measure GCPII activities in different tissues harvested from various disease models. The importance of [3 H]NAAG, combined with its current commercial unavailability, prompted the development of a reliable eight-step synthetic procedure towards [3 H2 ]NAAG starting from commercially available pyroglutamate. Pure [3 H]NAAG of high molar activity (49.8 Ci/mmol) and desired stereochemistry was isolated in high radiochemical yield (67 mCi) and radiochemical purity (>99%). The identity was confirmed by mass spectrometry and co-injection with unlabeled reference.
- Klíčová slova
- [2H]Glu, [3H]Glu, [3H]NAAG, labeled amino acid, microscale synthesis, tritium labeling,
- MeSH
- dipeptidy * farmakologie MeSH
- kyselina glutamová * MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- dipeptidy * MeSH
- kyselina glutamová * MeSH
The multifunctional radioligand [3 H]T0901317 ([3 H]1) has been employed as a powerful autoradiographic tool to target several receptors, such as liver X, farnesoid X, and retinoic acid-related orphan receptor alpha and gamma subtypes at nanomolar concentrations. Although [3 H]1 is commercially available and its synthesis via tritiodebromination has been reported, the market price of this radioligand and the laborious synthesis of corresponding bromo-intermediate potentially preclude its widespread use in biochemical, pharmacological, and pathological studies in research lab settings. We exploit recent reports on hydrogen-isotope exchange (HIE) reactions in tertiary benzenesulfonamides where the sulfonamide represents an ortho-directing group that facilitates CH activation in the presence of homogenous iridium(I) catalysts. Herein, we report a time- and cost-efficient method for the tritium late-stage labeling of compound 1-a remarkably electron-poor substrate owing to the tertiary trifluoroethylsulfonamide moiety. Under a straightforward HIE condition using a commercially available Kerr-type NHC Ir(I) complex, [(cod)Ir (NHC)Cl], the reaction with 1 afforded a specific activity of 10.8 Ci/mmol. Additionally, alternative HIE conditions using the heterogeneous catalyst of Ir-black provided sufficient 0.72 D-enrichment of 1 but unexpectedly failed while repeating with tritium gas.
- Klíčová slova
- D2 vs. T2 reactivity, T0901317, catalyst, hydrogen isotope exchange, iridium, late-stage-labeling, tertiary benzenesulfonamides, tetrafluoroethylsulfonamides,
- MeSH
- benzensulfonamidy MeSH
- elektrony * MeSH
- fluorokarbony MeSH
- izotopy MeSH
- katalýza MeSH
- sulfonamidy MeSH
- tritium chemie MeSH
- vodík * chemie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
- Názvy látek
- fluorokarbony MeSH
- izotopy MeSH
- sulfonamidy MeSH
- T0901317 MeSH Prohlížeč
- tritium MeSH
- vodík * MeSH
Convenient and straightforward synthesis of ibrutinib labeled by carbon-13 isotope is reported. Isotopically labeled building block is introduced in the last step of reaction sequence affording sufficient isolated yield (7%) of [13 C6 ]-ibrutinib calculated towards starting commercially available [13 C6 ]-bromobenzene.
- Klíčová slova
- [13C6]-ibrutinib, carbon-13, cost-effective synthesis, stable isotope labeling,
- MeSH
- adenin analogy a deriváty chemie MeSH
- brombenzeny chemie MeSH
- inhibitory proteinkinas chemie MeSH
- izotopy uhlíku chemie MeSH
- piperidiny chemie MeSH
- techniky syntetické chemie metody MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- adenin MeSH
- brombenzeny MeSH
- bromobenzene MeSH Prohlížeč
- ibrutinib MeSH Prohlížeč
- inhibitory proteinkinas MeSH
- izotopy uhlíku MeSH
- piperidiny MeSH
The key factors participating in angiogenesis include vascular endothelial growth factor (VEGF) and its receptors (VEGFRs), particularly VEGFR2. Angiogenesis suppression comprises the blocking of the VEGFR2 binding site by the monoclonal antibody ramucirumab (RAM). Our study focused on RAM radiolabelling with zirconium-89 along with subsequent in vitro and in vivo biological evaluation. RAM was conjugated with the bifunctional chelator p-SCN-Bn-deferoxamine (DFO) and subsequently radiolabelled with [89 Zr]Zr-oxalate. The binding affinity of [89 Zr]Zr-DFO-RAM to VEGFR2 was tested in vitro on prostate (PC-3) and ovary adenocarcinoma (SK-OV-3) cell lines. The positron emission tomography/computed tomography (PET/CT) imaging and ex vivo biodistribution experiments were performed in PC-3 and SK-OV-3 xenografted mice. The in vitro experiments revealed the preserved binding affinity of [89 Zr]Zr-DFO-RAM to VEGFR2. The obtained ex vivo biodistribution data showed the uptake in PC-3 and SK-OV-3 tumours at about 8.7 ± 0.2 and 12.1 ± 1.6%ID/g, respectively. The tumour-to-muscle ratio for 1, 3 and 6 days post injection was 3.9, 5.5 and 5.12 for PC-3 and 6.0, 8.0 and 8.82 for SK-OV-3 tumours, respectively. PET/CT images showed high radioactivity accumulation in the tumours starting already on the first day after tracer administration. The obtained results proved the potency of [89 Zr]Zr-DFO-RAM to target and image VEGFR2-positive tumours in vivo.
- Klíčová slova
- PET, VEGF, VEGFR, angiogenesis, monoclonal antibody, ramucirumab,
- MeSH
- humanizované monoklonální protilátky * chemie terapeutické užití farmakokinetika MeSH
- izotopové značení MeSH
- lidé MeSH
- monoklonální protilátky * chemie farmakokinetika MeSH
- myši MeSH
- nádorové buněčné linie MeSH
- PET/CT metody MeSH
- radionuklidy * chemie MeSH
- ramucirumab * MeSH
- receptor 2 pro vaskulární endoteliální růstový faktor * metabolismus antagonisté a inhibitory MeSH
- tkáňová distribuce MeSH
- zirkonium * chemie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- humanizované monoklonální protilátky * MeSH
- monoklonální protilátky * MeSH
- radionuklidy * MeSH
- ramucirumab * MeSH
- receptor 2 pro vaskulární endoteliální růstový faktor * MeSH
- Zirconium-89 MeSH Prohlížeč
- zirkonium * MeSH
CART (cocaine- and amphetamine-regulated transcript) peptides are involved in food intake regulation, stress, and other physiological functions. Although CART peptides have been known for over 25 years, their receptor(s) have not yet been characterized. In this short review, we will summarize our previous studies, where we reported specific binding of 125 I-CART(61-102) to PC12 rat pheochromocytoma cells. Competitive binding experiments performed with mono- and di-iodinated peptides and their isoforms with oxidized Met67 resulted in nanomolar binding affinity. Moreover, in our previous study, CART(61-102), as well as di-iodinated CART(61-102), have shown a strong anorexigenic effect in fasted lean mice after intracerebroventricular administration. In conclusion, from our previous studies, iodination of CART(61-102) resulted in mono- and di-iodinated analogs with or without oxidized Met67 . All analogs revealed a high affinity to binding sites at PC12 cells and preserved biological activity.
- Klíčová slova
- CART peptide, PC12 cells, competitive binding experiments, food intake,
- MeSH
- anorektika chemie farmakokinetika terapeutické užití MeSH
- buňky PC12 MeSH
- kokainem a amfetaminem regulovaný transkript MeSH
- krysa rodu Rattus MeSH
- myši MeSH
- proteiny nervové tkáně chemie farmakokinetika terapeutické užití MeSH
- radiofarmaka chemie farmakokinetika terapeutické užití MeSH
- radioizotopy jodu chemie MeSH
- vazba proteinů MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- Názvy látek
- anorektika MeSH
- kokainem a amfetaminem regulovaný transkript MeSH
- proteiny nervové tkáně MeSH
- radiofarmaka MeSH
- radioizotopy jodu MeSH
