| 1. |
- Bergman, Sara, et al.
(författare)
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Synthesis of 11C-Labelled Ureas by Palladium(II)-Mediated Oxidative Carbonylation
- 2017
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Ingår i: Molecules. - : MDPI AG. - 1431-5157 .- 1420-3049. ; 22:10
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Tidskriftsartikel (refereegranskat)abstract
- Positron emission tomography is an imaging technique with applications in clinical settings as well as in basic research for the study of biological processes. A PET tracer, a biologically active molecule where a positron-emitting radioisotope such as carbon-11 has been incorporated, is used for the studies. Development of robust methods for incorporation of the radioisotope is therefore of the utmost importance. The urea functional group is present in many biologically active compounds and is thus an attractive target for incorporation of carbon-11 in the form of [C-11] carbon monoxide. Starting with amines and [C-11] carbon monoxide, both symmetrical and unsymmetrical C-11-labelled ureas were synthesised via a palladium(II)-mediated oxidative carbonylation and obtained in decay-corrected radiochemical yields up to 65%. The added advantage of using [C-11] carbon monoxide was shown by the molar activity obtained for an inhibitor of soluble epoxide hydrolase (247 GBq/mu mol-319 GBq/mu mol). DFT calculations were found to support a reaction mechanism proceeding through an C-11-labelled isocyanate intermediate.
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| 2. |
- Bursill, D., et al.
(författare)
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Gout, Hyperuricaemia and Crystal-Associated Disease Network (G-CAN) consensus statement regarding labels and definitions of disease states of gout
- 2019
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Ingår i: Annals of the Rheumatic Diseases. - : BMJ. - 0003-4967 .- 1468-2060. ; 78:11, s. 1592-1600
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Tidskriftsartikel (refereegranskat)abstract
- Objective There is a lack of standardisation in the terminology used to describe gout. The aim of this project was to develop a consensus statement describing the recommended nomenclature for disease states of gout. Methods A content analysis of gout-related articles from rheumatology and general internal medicine journals published over a 5-year period identified potential disease states and the labels commonly assigned to them. Based on these findings, experts in gout were invited to participate in a Delphi exercise and face-to-face consensus meeting to reach agreement on disease state labels and definitions. Results The content analysis identified 13 unique disease states and a total of 63 unique labels. The Delphi exercise (n=76 respondents) and face-to-face meeting (n=35 attendees) established consensus agreement for eight disease state labels and definitions. The agreed labels were as follows: 'asymptomatic hyperuricaemia', 'asymptomatic monosodium urate crystal deposition', 'asymptomatic hyperuricaemia with monosodium urate crystal deposition', 'gout', 'tophaceous gout', 'erosive gout', 'first gout flare' and 'recurrent gout flares'. There was consensus agreement that the label 'gout' should be restricted to current or prior clinically evident disease caused by monosodium urate crystal deposition (gout flare, chronic gouty arthritis or subcutaneous tophus). Conclusion Consensus agreement has been established for the labels and definitions of eight gout disease states, including 'gout' itself. The Gout, Hyperuricaemia and Crystal-Associated Disease Network recommends the use of these labels when describing disease states of gout in research and clinical practice.
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| 3. |
- Eriksson, Jonas, et al.
(författare)
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Synthesis and preclinical evaluation of the CRTH2 antagonist [11C]MK-7246 as a novel PET tracer and potential surrogate marker for pancreatic beta-cell mass
- 2019
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Ingår i: Nuclear Medicine and Biology. - : Elsevier BV. - 0969-8051 .- 1872-9614. ; 71, s. 1-10
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: MK-7246 is a potent and selective antagonist for chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2). Within the pancreas CRTH2 is selectively expressed in pancreatic β-cells where it is believed to play a role in insulin release. Reduction in β-cell mass and insufficient insulin secretion in response to elevated blood glucose levels is a hallmark for type 1 and type 2 diabetes. Reported here is the synthesis of [11C]MK-7246 and initial preclinical evaluation towards CRTH2 imaging. The aim is to develop a method to quantify β-cell mass with PET and facilitate non-invasive studies of disease progression in individuals with type 2 diabetes.Methods: The precursor N-desmethyl-O-methyl MK-7246 was synthesized in seven steps and subjected to methylation with [11C]methyl iodide followed by hydrolysis to obtain [11C]MK-7246 labelled in the N-methyl position. Preclinical evaluation included in vitro radiography and immune-staining performed in human pancreatic biopsies. Biodistribution studies were performed in rat by PET-MRI and in pig by PET-CT imaging. The specific tracer uptake was examined in pig by scanning before and after administration of MK-7246 (1 mg/kg). Predicted dosimetry of [11C]MK-7246 in human males was estimated based on the biodistribution in rat.Results: [11C]MK-7246 was obtained with activities sufficient for the current investigations (270±120 MBq) and a radiochemical purity of 93±2%. The tracer displayed focal binding in areas with insulin positive islet of Langerhans in human pancreas sections. Baseline uptake in pig was significantly reduced in CRTH2-rich areas after administration of MK-7246; pancreas (66% reduction) and spleen (88% reduction). [11C]MK-7246 exhibited a safe human predicted dosimetry profile as extrapolated from the rat biodistribution data.Conclusions: Initial preclinical in vitro and in vivo evaluation of [11C]MK-7246 show binding and biodistribution properties suitable for PET imaging of CRTH2. Further studies are warranted to assess its potential in β-cell mass imaging and CRTH2 drug development.
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| 4. |
- Roslin, Sara
(författare)
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Exploring Palladium-Mediated 11C/12C-Carbonylation Reactions : PET Tracer Development Targeting the Vesicular Acetylcholine Transporter
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The work presented herein describes the utilization and exploration of palladium-mediated incorporations of carbon monoxide and/or [11C]carbon monoxide into compounds and structural motifs with biological relevance.The first part of the thesis describes the design, synthesis and 11C-labeling of prospective PET tracers for the vesicular acetylcholine transporter (VAChT), a target affected in several neurodegenerative diseases. Different parts of the benzovesamicol scaffold were modified in papers I and II to probe the binding to VAChT. The key motif was an amide functional group, which enabled the use of palladium-mediated 11C/12C-carbonylations to synthesize and evaluate two different sets of structurally related ligands.The second part of the thesis describes the exploration of different aspects of palladium-mediated 11C/12C-carbonylation reactions. The utilization of unactivated alkyl iodides and bromides as coupling partners in a carbonylative Suzuki-Miyaura reaction was described in paper III. The combination of palladium-catalysis together with visible light irradiation enabled their functionalization via an alkyl radical. The mild conditions, namely the ambient temperature and pressure of carbon monoxide, and the accessible reaction set-up further added to the utility of the method. A palladium(II)-mediated oxidative 11C-carbonylation for synthesis of 11C-labeled ureas was described in paper IV. Utilizing only amines in addition to a palladium-source and [11C]carbon monoxide, the method proved to be facile and robust, thus representing a simplification in relation to methods using other 11C-synthons for synthesis of 11C-labeled ureas. Finally, a palladium(0)-catalyzed carbonylation reaction for synthesis of acylamidines was presented in paper V. The versatility of the method was demonstrated by one-pot cyclizations to form oxadiazoles and triazoles together with the corresponding 11C-carbonylation reaction to produce 11C-labeled acylamidines and an oxadiazole.The work described herein has thus contributed structural information in the search for a PET tracer for VAChT and identified a viable lead structure for future investigations. Furthermore, investigation of reaction conditions that would allow use of either elusive or accessible substrates led to the development of methods for synthesis and/or 11C-labeling of various carbonylated compounds.
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| 5. |
- Roslin, Sara, et al.
(författare)
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Synthesis and In Vitro Evaluation of 5-Substituted Benzovesamicol Analogs containing N-Substituted Amides as Potential Positron Emission Tomography Tracers for the Vesicular Acetylcholine Transporter
- 2017
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Ingår i: Bioorganic & Medicinal Chemistry. - : Elsevier BV. - 0968-0896 .- 1464-3391. ; 25:19, s. 5095-5106
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Tidskriftsartikel (refereegranskat)abstract
- Herein, new ligands for the vesicular acetylcholine transporter (VAChT), based on a benzovesamicol scaffold, are presented. VAChT is acknowledged as a marker for cholinergic neurons and a positron emission tomography tracer for VAChT could serve as a tool for quantitative analysis of cholinergic neuronal density. With an easily accessible triflate precursor, aminocarbonylations were utilized to evaluate the chemical space around the C5 position on the tetrahydronaphthol ring. Synthesized ligands were evaluated for their affinity and selectivity for VAChT. Small, preferably aromatic, N-substituents proved to be more potent than larger substituents. Of the fifteen compounds synthesized, benzyl derivatives (+/-)-7i and (+/-)-7l had the highest affinities for VAChT. Compound (+/-)-7i was chosen to investigate the importance of stereochemistry for binding to VAChT and selectivity toward the sigma(1) and sigma(2) receptors. Enantiomeric resolution gave (+/-)-7i and (-)-7i, and the eutomer showed seven times better affinity. Although racemate (+/-)-7i was initially promising, the affinity of (-)-7i for VAChT was not better than 56.7 nM which precludes further preclinical evaluation. However, the nanomolar binding together with the ready synthesis of [C-11]-(+/-)-7i shows that (-)-7i can serve as a scaffold for future optimizations to provide improved C-11-labelled VAChT PET tracers.
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| 6. |
- Rydfjord, Jonas, et al.
(författare)
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Route to 3-Amidino Indoles via Pd(II)-Catalyzed C-H Bond Activation
- 2017
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Ingår i: Organic Letters. - : American Chemical Society (ACS). - 1523-7060 .- 1523-7052. ; 19:15, s. 4066-4069
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Tidskriftsartikel (refereegranskat)abstract
- We report a facile synthesis of 3-amidino indoles from indoles and cyanamides. The reaction is Pd(II)-catalyzed and proceeds via C-H bond activation of the indole in its 3-position followed by a 1,2-addition of the resulting indole-palladium σ-complex to a cyanamide, which provides the corresponding amidine. The preference for 4,5-diazafluoren-9-one (DAF) as the ligand is investigated using DFT calculations, and a plausible reaction pathway is presented.
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| 7. |
- Stevens, Marc, 1984-
(författare)
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Multicomponent Reactions in 11C/12C Chemistry : – Targeting the Angiotensin II Subtype 2 Receptor
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Section 1 of this thesis contains an introduction to method development in organic synthesis, multicomponent reactions, sulfonyl azides, tracer development in 11C chemistry and the biological target.Section 2 describes the use of sulfonyl azides in carbonylative chemistry. Paper I covers development of a diazotransfer protocol. In total, 30 arylsulfonyl azides were synthesised from primary sulfonamides (20–90% yield). 15N mechanistic studies were carried out and in Paper II, the products were converted into sulfonamides, sulfonylureas and sulfonyl carbamates (19–90% yield). For ureas and carbamates, a two-chamber protocol was employed to release CO from Mo(CO)6. 15N mechanistic studies showed that the sulfonamides were formed by direct displacement of azide.Section 3 covers imaging and biological studies of the angiotensin II receptor subtype 2 (AT2R). In Paper III, 12 11C-sulfonyl carbamates were prepared in isolated radiochemical yields of 3–51% via Rh(I)-mediated carbonylation. The first non-peptide AT2R agonist, C21, was labelled (isolated RCY 24±10%, SA 34–51 GBq/µmol). C21 was tested in a prostate cancer assay, followed by biodistribution and small-animal PET studies. In Paper IV, a 11C-labelled AT2R ligand prepared via Pd(0)-mediated aminocarbonylation was used for autoradiography, biodistribution and small-animal PET studies. Section 4 describes the development of a multicomponent method for the synthesis of 3,4-dihydroquinazolinones (Paper V). 31 3,4-dihydroquinazolinones were synthesized via a cyclic iminium ion.
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| 8. |
- Stevens, Marc, 1984-, et al.
(författare)
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Synthesis of 11C-labelled Sulfonyl Carbamates via a Multicomponent Reaction Employing Sulfonyl Azides, Alcohols and [11C]CO
- 2016
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Ingår i: ChemistryOpen. - : John Wiley & Sons. - 2191-1363. ; 5:6, s. 566-573
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Tidskriftsartikel (refereegranskat)abstract
- Herein we describe the development of new methodologyfocusing on 11C-labelling of sulfonyl carbamates in a multicomponentreaction comprising a sulfonyl azide, an alkyl alcohol and [11C]CO. Anumber of 11C-labelled sulfonyl carbamates were synthesised andisolated, and the developed methodology was then applied in thepreparation of a biologically active molecule. The target compoundwas obtained in 18±8% isolated radiochemical yield and wasevaluated for binding properties in a tumor cell assay, as well asundergoing in vivo biodistribution and imaging studies. Thisrepresents the first successful radiolabelling of C21, a non-peptideangiotensin II receptor subtype 2 agonist currently in clinical trials.
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| 9. |
- Stevens, Marc Y., et al.
(författare)
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Synthesis of C-11-labeled Sulfonyl Carbamates through a Multicomponent Reaction Employing Sulfonyl Azides, Alcohols, and [C-11]CO
- 2016
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Ingår i: ChemistryOpen. - : Wiley. - 2191-1363. ; 5:6, s. 566-573
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Tidskriftsartikel (refereegranskat)abstract
- We describe the development of a new methodology focusing on C-11-labeling of sulfonyl carbamates in a multicomponent reaction comprised of a sulfonyl azide, an alkyl alcohol, and [C-11] CO. A number of C-11-labeled sulfonyl carbamates were synthesized and isolated, and the developed methodology was then applied in the preparation of a biologically active molecule. The target compound was obtained in 24 +/- 10% isolated radiochemical yield and was evaluated for binding properties in a tumor cell assay; in vivo biodistribution and imaging studies were also performed. This represents the first successful radiolabeling of a non-peptide angiotensin II receptor subtype 2 agonist, C21, currently in clinical trials for the treatment of idiopathic pulmonary fibrosis.
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| 10. |
- Åkerbladh, Linda
(författare)
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Palladium(0)-Catalysed Carbonylative Multicomponent Reactions : Synthesis of Heterocycles and the Application of Quinolinyl Pyrimidines as Enzyme Inhibitors
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Palladium-catalysed carbonylative multicomponent reactions have proven useful for the synthesis of structurally diverse compounds. Carbon monoxide serves as an atom-efficient, one-carbon building block, which allows for further structural elaboration of the carbonyl compound. By varying the components of the carbonylative multicomponent reaction, considerable product diversity can readily be attained. However, due to the reluctance to use toxic CO gas, considerable efforts have been directed at exploring non-gaseous approaches. The work described in this thesis has mainly focused on the development of palladium(0)-catalysed, carbonylative multicomponent synthetic methodology, using the non-gaseous CO source molybdenum hexacarbonyl, in the synthesis of heterocycles and other biologically relevant functional groups.The first part of this work describes the development of a non-gaseous carbonylative Sonogashira cross-coupling of bifunctional ortho-iodoanilines and terminal alkynes. Where 4-quinolones were synthesised via a carbonylation/cyclisation sequence. Using a similar synthetic strategy, three different N-cyanobenzamide intermediates were prepared by palladium-catalysed carbonylative couplings of various aryl halides and bromides and cyanamide. The formed intermediates provided a basis for further chemical transformations. First, ortho-iodoanilines were carbonylatively coupled with cyanamide and subsequently cyclised to yield heterocyclic 2-aminoquinazolinones. Next, building on those findings, the same synthetic strategy was applied to ortho-halophenols to provide a highly convenient domino carbonylation/cyclisation method for the preparation of benzoxazinones. The developed method was used to evaluate the efficiency of various non-gaseous CO sources. Third, the palladium-catalysed carbonylative synthesis of N-cyanobenzamides, was used to produce biologically relevant N-acylguanidines with considerable product diversity. Finally, one of the developed carbonylative methodologies was used in the preparation of potential NDH-2 inhibitors based on a quinolinyl pyrimidine scaffold. The prepared compounds were biologically evaluated in terms of inhibition of oxidoreductase NDH-2 and antibacterial activity on Gram-negative bacteria, S. aureus and Mtb. The biological evaluation revealed that some of the quinolinyl pyrimidines exerted inhibitory activity on the NDH-2 enzyme and possessed antibacterial properties.The work described in this thesis has been devoted to the development of non-gaseous one-pot, multicomponent carbonylation/cyclisation and carbonylation/amination reactions. The described methods offer highly attractive synthetic strategies that can be of great value to synthetic and medicinal chemists.
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