| 1. |
- Vos, Theo, et al.
(författare)
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Global, regional, and national incidence, prevalence, and years lived with disability for 301 acute and chronic diseases and injuries in 188 countries, 1990-2013: a systematic analysis for the Global Burden of Disease Study 2013
- 2015
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Ingår i: The Lancet. - 1474-547X .- 0140-6736. ; 386:9995, s. 743-800
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Tidskriftsartikel (refereegranskat)abstract
- Background Up-to-date evidence about levels and trends in disease and injury incidence, prevalence, and years lived with disability (YLDs) is an essential input into global, regional, and national health policies. In the Global Burden of Disease Study 2013 (GBD 2013), we estimated these quantities for acute and chronic diseases and injuries for 188 countries between 1990 and 2013. Methods Estimates were calculated for disease and injury incidence, prevalence, and YLDs using GBD 2010 methods with some important refinements. Results for incidence of acute disorders and prevalence of chronic disorders are new additions to the analysis. Key improvements include expansion to the cause and sequelae list, updated systematic reviews, use of detailed injury codes, improvements to the Bayesian meta-regression method (DisMod-MR), and use of severity splits for various causes. An index of data representativeness, showing data availability, was calculated for each cause and impairment during three periods globally and at the country level for 2013. In total, 35 620 distinct sources of data were used and documented to calculated estimates for 301 diseases and injuries and 2337 sequelae. The comorbidity simulation provides estimates for the number of sequelae, concurrently, by individuals by country, year, age, and sex. Disability weights were updated with the addition of new population-based survey data from four countries. Findings Disease and injury were highly prevalent; only a small fraction of individuals had no sequelae. Comorbidity rose substantially with age and in absolute terms from 1990 to 2013. Incidence of acute sequelae were predominantly infectious diseases and short-term injuries, with over 2 billion cases of upper respiratory infections and diarrhoeal disease episodes in 2013, with the notable exception of tooth pain due to permanent caries with more than 200 million incident cases in 2013. Conversely, leading chronic sequelae were largely attributable to non-communicable diseases, with prevalence estimates for asymptomatic permanent caries and tension-type headache of 2.4 billion and 1.6 billion, respectively. The distribution of the number of sequelae in populations varied widely across regions, with an expected relation between age and disease prevalence. YLDs for both sexes increased from 537.6 million in 1990 to 764.8 million in 2013 due to population growth and ageing, whereas the age-standardised rate decreased little from 114.87 per 1000 people to 110.31 per 1000 people between 1990 and 2013. Leading causes of YLDs included low back pain and major depressive disorder among the top ten causes of YLDs in every country. YLD rates per person, by major cause groups, indicated the main drivers of increases were due to musculoskeletal, mental, and substance use disorders, neurological disorders, and chronic respiratory diseases; however HIV/AIDS was a notable driver of increasing YLDs in sub-Saharan Africa. Also, the proportion of disability-adjusted life years due to YLDs increased globally from 21.1% in 1990 to 31.2% in 2013. Interpretation Ageing of the world's population is leading to a substantial increase in the numbers of individuals with sequelae of diseases and injuries. Rates of YLDs are declining much more slowly than mortality rates. The non-fatal dimensions of disease and injury will require more and more attention from health systems. The transition to non-fatal outcomes as the dominant source of burden of disease is occurring rapidly outside of sub-Saharan Africa. Our results can guide future health initiatives through examination of epidemiological trends and a better understanding of variation across countries.
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| 2. |
- Abbafati, Cristiana, et al.
(författare)
-
- 2020
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Tidskriftsartikel (refereegranskat)
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| 3. |
- Naghavi, Mohsen, et al.
(författare)
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Global, regional, and national age-sex specific all-cause and cause-specific mortality for 240 causes of death, 1990-2013: a systematic analysis for the Global Burden of Disease Study 2013
- 2015
-
Ingår i: The Lancet. - 1474-547X .- 0140-6736. ; 385:9963, s. 117-171
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Tidskriftsartikel (refereegranskat)abstract
- Background Up-to-date evidence on levels and trends for age-sex-specifi c all-cause and cause-specifi c mortality is essential for the formation of global, regional, and national health policies. In the Global Burden of Disease Study 2013 (GBD 2013) we estimated yearly deaths for 188 countries between 1990, and 2013. We used the results to assess whether there is epidemiological convergence across countries. Methods We estimated age-sex-specifi c all-cause mortality using the GBD 2010 methods with some refinements to improve accuracy applied to an updated database of vital registration, survey, and census data. We generally estimated cause of death as in the GBD 2010. Key improvements included the addition of more recent vital registration data for 72 countries, an updated verbal autopsy literature review, two new and detailed data systems for China, and more detail for Mexico, UK, Turkey, and Russia. We improved statistical models for garbage code redistribution. We used six different modelling strategies across the 240 causes; cause of death ensemble modelling (CODEm) was the dominant strategy for causes with sufficient information. Trends for Alzheimer's disease and other dementias were informed by meta-regression of prevalence studies. For pathogen-specifi c causes of diarrhoea and lower respiratory infections we used a counterfactual approach. We computed two measures of convergence (inequality) across countries: the average relative difference across all pairs of countries (Gini coefficient) and the average absolute difference across countries. To summarise broad findings, we used multiple decrement life-tables to decompose probabilities of death from birth to exact age 15 years, from exact age 15 years to exact age 50 years, and from exact age 50 years to exact age 75 years, and life expectancy at birth into major causes. For all quantities reported, we computed 95% uncertainty intervals (UIs). We constrained cause-specific fractions within each age-sex-country-year group to sum to all-cause mortality based on draws from the uncertainty distributions. Findings Global life expectancy for both sexes increased from 65.3 years (UI 65.0-65.6) in 1990, to 71.5 years (UI 71.0-71.9) in 2013, while the number of deaths increased from 47.5 million (UI 46.8-48.2) to 54.9 million (UI 53.6-56.3) over the same interval. Global progress masked variation by age and sex: for children, average absolute diff erences between countries decreased but relative diff erences increased. For women aged 25-39 years and older than 75 years and for men aged 20-49 years and 65 years and older, both absolute and relative diff erences increased. Decomposition of global and regional life expectancy showed the prominent role of reductions in age-standardised death rates for cardiovascular diseases and cancers in high-income regions, and reductions in child deaths from diarrhoea, lower respiratory infections, and neonatal causes in low-income regions. HIV/AIDS reduced life expectancy in southern sub-Saharan Africa. For most communicable causes of death both numbers of deaths and age-standardised death rates fell whereas for most non-communicable causes, demographic shifts have increased numbers of deaths but decreased age-standardised death rates. Global deaths from injury increased by 10.7%, from 4.3 million deaths in 1990 to 4.8 million in 2013; but age-standardised rates declined over the same period by 21%. For some causes of more than 100 000 deaths per year in 2013, age-standardised death rates increased between 1990 and 2013, including HIV/AIDS, pancreatic cancer, atrial fibrillation and flutter, drug use disorders, diabetes, chronic kidney disease, and sickle-cell anaemias. Diarrhoeal diseases, lower respiratory infections, neonatal causes, and malaria are still in the top five causes of death in children younger than 5 years. The most important pathogens are rotavirus for diarrhoea and pneumococcus for lower respiratory infections. Country-specific probabilities of death over three phases of life were substantially varied between and within regions. Interpretation For most countries, the general pattern of reductions in age-sex specifi c mortality has been associated with a progressive shift towards a larger share of the remaining deaths caused by non-communicable disease and injuries. Assessing epidemiological convergence across countries depends on whether an absolute or relative measure of inequality is used. Nevertheless, age-standardised death rates for seven substantial causes are increasing, suggesting the potential for reversals in some countries. Important gaps exist in the empirical data for cause of death estimates for some countries; for example, no national data for India are available for the past decade.
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| 4. |
- Stanaway, Jeffrey D., et al.
(författare)
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Global, regional, and national comparative risk assessment of 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks for 195 countries and territories, 1990-2017: A systematic analysis for the Global Burden of Disease Study 2017
- 2018
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Ingår i: The Lancet. - 1474-547X .- 0140-6736. ; 392:10159, s. 1923-1994
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Tidskriftsartikel (refereegranskat)abstract
- Background The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017 comparative risk assessment (CRA) is a comprehensive approach to risk factor quantification that offers a useful tool for synthesising evidence on risks and risk-outcome associations. With each annual GBD study, we update the GBD CRA to incorporate improved methods, new risks and risk-outcome pairs, and new data on risk exposure levels and risk- outcome associations. Methods We used the CRA framework developed for previous iterations of GBD to estimate levels and trends in exposure, attributable deaths, and attributable disability-adjusted life-years (DALYs), by age group, sex, year, and location for 84 behavioural, environmental and occupational, and metabolic risks or groups of risks from 1990 to 2017. This study included 476 risk-outcome pairs that met the GBD study criteria for convincing or probable evidence of causation. We extracted relative risk and exposure estimates from 46 749 randomised controlled trials, cohort studies, household surveys, census data, satellite data, and other sources. We used statistical models to pool data, adjust for bias, and incorporate covariates. Using the counterfactual scenario of theoretical minimum risk exposure level (TMREL), we estimated the portion of deaths and DALYs that could be attributed to a given risk. We explored the relationship between development and risk exposure by modelling the relationship between the Socio-demographic Index (SDI) and risk-weighted exposure prevalence and estimated expected levels of exposure and risk-attributable burden by SDI. Finally, we explored temporal changes in risk-attributable DALYs by decomposing those changes into six main component drivers of change as follows: (1) population growth; (2) changes in population age structures; (3) changes in exposure to environmental and occupational risks; (4) changes in exposure to behavioural risks; (5) changes in exposure to metabolic risks; and (6) changes due to all other factors, approximated as the risk-deleted death and DALY rates, where the risk-deleted rate is the rate that would be observed had we reduced the exposure levels to the TMREL for all risk factors included in GBD 2017.
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| 5. |
- Fridjonsdottir, Elva, et al.
(författare)
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Mass spectrometry imaging identifies abnormally elevated brain L-DOPA levels and extrastriatal monoaminergic dysregulation in L-DOPA-induced dyskinesia
- 2021
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Ingår i: Science Advances. - : American Association for the Advancement of Science (AAAS). - 2375-2548. ; 7:2
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Tidskriftsartikel (refereegranskat)abstract
- L-DOPA treatment for Parkinson's disease frequently leads to dyskinesias, the pathophysiology of which is poorly understood. We used MALDI-MSI to map the distribution of L-DOPA and monoaminergic pathways in brains of dyskinetic and nondyskinetic primates. We report elevated levels of L-DOPA, and its metabolite 3-O-methyldopa, in all measured brain regions of dyskinetic animals and increases in dopamine and metabolites in all regions analyzed except the striatum. In dyskinesia, dopamine levels correlated well with L-DOPA levels in extrastriatal regions, such as hippocampus, amygdala, bed nucleus of the stria terminalis, and cortical areas, but not in the striatum. Our results demonstrate that L-DOPA-induced dyskinesia is linked to a dysregulation of L-DOPA metabolism throughout the brain. The inability of extrastriatal brain areas to regulate the formation of dopamine during L-DOPA treatment introduces the potential of dopamine or even L-DOPA itself to modulate neuronal signaling widely across the brain, resulting in unwanted side effects.
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| 6. |
- Fridjonsdottir, Elva, et al.
(författare)
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Region-Specific and Age-Dependent Multitarget Effects of Acetylcholinesterase Inhibitor Tacrine on Comprehensive Neurotransmitter Systems
- 2022
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Ingår i: ACS Chemical Biology. - : American Chemical Society (ACS). - 1554-8929 .- 1554-8937. ; 17:1, s. 147-158
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Tidskriftsartikel (refereegranskat)abstract
- Regional brain distribution and metabolism of neurotransmitters and their response to drug treatment are fundamentally important for understanding the central effects of neuroactive substances. We used matrix-assisted laser desorption/ionization mass spectrometry imaging in combination with multivariate analysis to visualize in anatomical detail metabolic effects of aging and tacrine-mediated acetylcholinesterase inhibition on comprehensive neurotransmitter systems in multiple mouse brain regions of 12-week-old and 14-month-old mice. We detected age-related increases in 3,4-dihydroxyphenylacetaldehyde and histamine, indicating oxidative stress and aging deficits in astrocytes. Tacrine had a significant impact on the metabolism of neurotransmitters in both age groups; predominantly, there was an increased norepinephrine turnover throughout the brain and decreased 3-methoxy tyramine, a marker for dopamine release, in the striatum. The striatal levels of histamine were only elevated after tacrine administration in the older animals. Our results demonstrated that tacrine is a multitarget and region-specific neuroactive agent, inducing age-specific responses. Although well-studied, the complete mechanisms of the action of tacrine are not fully understood, and the current findings reveal features that may help explain its treatment-related effectiveness and central side effects.
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| 7. |
- Gising, Johan, et al.
(författare)
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Trisubstituted Imidazoles as Mycobacterium tuberculosis Glutamine Synthetase Inhibitors
- 2012
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Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society (ACS). - 0022-2623 .- 1520-4804. ; 55:6, s. 2894-2898
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Tidskriftsartikel (refereegranskat)abstract
- Mycobacterium tuberculosis glutamine synthetase (MtGS) is a promising target for antituberculosis drug discovery. In a recent high-throughput screening study we identified several classes of MtGS inhibitors targeting the ATP-binding site. We now explore one of these classes, the 2-tert-butyl-4,5-diarylimidazoles, and present the design, synthesis, and X-ray crystallographic studies leading to the identification of MtGS inhibitors with submicromolar IC(50) values and promising antituberculosis MIC values.
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| 8. |
- Kaya, Ibrahim, et al.
(författare)
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On-Tissue Chemical Derivatization for Comprehensive Mapping of Brain Carboxyl and Aldehyde Metabolites by MALDI-MS Imaging
- 2023
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Ingår i: Journal of the American Society for Mass Spectrometry. - : American Chemical Society (ACS). - 1044-0305 .- 1879-1123. ; 34:5, s. 836-846
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Tidskriftsartikel (refereegranskat)abstract
- The visualization of small metabolites by MALDI mass spectrometry imaging in brain tissue sections is challenging due to low detection sensitivity and high background interference. We present an on-tissue chemical derivatization MALDI mass spectrometry imaging approach for the comprehensive mapping of carboxyls and aldehydes in brain tissue sections. In this approach, the AMPP (1-(4-(aminomethyl)phenyl)pyridin-1-ium chloride) derivatization reagent is used for the covalent charge-tagging of molecules containing carboxylic acid (in the presence of peptide coupling reagents) and aldehydes. This includes free fatty acids and the associated metabolites, fatty aldehydes, dipeptides, neurotoxic reactive aldehydes, amino acids, neurotransmitters and associated metabolites, as well as tricarboxylic acid cycle metabolites. We performed sensitive ultrahigh mass resolution MALDI-MS detection and imaging of various carboxyl-and aldehyde containing endogenous metabolites simultaneously in rodent brain tissue sections. We verified the AMPP-derivatized metabolites by tandem MS for structural elucidation. This approach allowed us to image numerous aldehydes and carboxyls, including certain metabolites which had been undetectable in brain tissue sections. We also demonstrated the application of on-tissue derivatization to carboxyls and aldehydes in coronal brain tissue sections of a nonhuman primate Parkinson's disease model. Our methodology provides a powerful tool for the sensitive, simultaneous spatial molecular imaging of numerous aldehydes and carboxylic acids during pathological states, including neurodegeneration, in brain tissue.
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| 9. |
- Nordeman, Patrik, et al.
(författare)
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Palladium-mediated C-11-carbonylations using aryl halides and cyanamide
- 2017
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Ingår i: Organic and biomolecular chemistry. - : Royal Society of Chemistry (RSC). - 1477-0520 .- 1477-0539. ; 15:22, s. 4875-4881
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Tidskriftsartikel (refereegranskat)abstract
- A robust and high-yielding radiochemical synthesis of C-11-N-cyanobenzamides using a palladium-mediated aminocarbonylation with C-11-CO, aryl halides and cyanamide is described. The bidentate ligand 1,1'-bis(diphenylphosphino)ferrocene provided C-11-N-cyanobenzamides from aryl-iodides, bromides, triflates and even chlorides in 28-79% radiochemical yield after semi-preparative HPLC. To further highlight the utility of this method, novel C-11-N-cyanobenzamide analogs of flufenamic acid, meflanamic acid, dazoxiben and tamibarotene were synthesized in 34-71% radiochemical yields.
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| 10. |
- Nordqvist, Anneli, et al.
(författare)
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Synthesis, biological evaluation and X-ray crystallographic studies of imidazo[1,2-a]-pyridine based Mycobacterium tuberculosis glutamine synthetase inhibitors
- 2012
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Ingår i: MedChemComm. - : Royal Society of Chemistry (RSC). - 2040-2503 .- 2040-2511. ; 3:5, s. 620-626
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Tidskriftsartikel (refereegranskat)abstract
- Based on an imidazo[1,2-a]pyridine hit from a high-throughput screen directed at the M. tuberculosis enzyme glutamine synthetase, a hit expansion was performed by synthesizing a series of analogs. A set of 16 molecules was first synthesized according to a statistical molecular design approach. One potent inhibitor was identified (IC50 = 3.0 µM), which led to the synthesis of 17 additional imidazo[1,2-a]pyridines in a follow-up study. Among these, several inhibitors were identified showing single digit micromolar potency. An X-ray structure of one of these revealed the binding mode of this class of inhibitors in the ATP-binding site, and allowed us to rationalize some of the structure-activity relationships observed.
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| 11. |
- Odell, Adam F, et al.
(författare)
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A Novel p53 Mutant Found in Iatrogenic Urothelial Cancers Is Dysfunctional and Can Be Rescued by a Second-site Global Suppressor Mutation
- 2013
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Ingår i: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 288:23, s. 16704-16714
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Tidskriftsartikel (refereegranskat)abstract
- Exposure to herbal remedies containing the carcinogen aristolochic acid (AA) has been widespread in some regions of the world. Rare A→T TP53 mutations were recently discovered in AA-associated urothelial cancers. The near absence of these mutations among all other sequenced human tumors suggests that they could be biologically silent. There are no cell banks with established lines derived from human tumors with which to explore the influence of the novel mutants on p53 function and cellular behavior. To investigate their impact, we generated isogenic mutant clones by integrase-mediated cassette exchange at the p53 locus of platform (null) murine embryonic fibroblasts and kidney epithelial cells. Common tumor mutants (R248W, R273C) were compared with the AA-associated mutants N131Y, R249W, and Q104L. Assays of cell proliferation, migration, growth in soft agar, apoptosis, senescence, and gene expression revealed contrasting outcomes on cellular behavior following introduction of N131Y or Q104L. The N131Y mutant demonstrated a phenotype akin to common tumor mutants, whereas Q104L clone behavior resembled that of cells with wild-type p53. Wild-type p53 responses were restored in double-mutant cells harboring N131Y and N239Y, a second-site rescue mutation, suggesting that pharmaceutical reactivation of p53 function in tumors expressing N131Y could have therapeutic benefit. N131Y is likely to contribute directly to tumor phenotype and is a promising candidate biomarker of AA exposure and disease. Rare mutations thus do not necessarily point to sites where amino acid exchanges are phenotypically neutral. Encounter with mutagenic insults targeting cryptic sites can reveal specific signature hotspots.
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| 12. |
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| 13. |
- Odell, Luke R., et al.
(författare)
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Crystal and Molecular Structures of Benzyl-(2-chloro-6-methylpyrimidin-4-yl)amine and Benzyl-(4-chloro-6-methylpyrimidin-2-yl)amine : Confirmation of Computationally Predicted Restricted Rotation
- 2007
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Ingår i: Journal of Chemical Crystallography. - : Springer Science and Business Media LLC. - 1074-1542 .- 1572-8854. ; 37:12, s. 817-824
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Tidskriftsartikel (refereegranskat)abstract
- Crystal structures for the isomeric compounds benzyl-(2-chloro-6-methylpyrimidin-4-yl)amine (1), as its hemi-hydrate, and benzyl-(4-chloro-6-methylpyrimidin-2-yl)amine (2) have been determined. Conformational differences lead to multiple molecules, i.e. two and three, in their respective structures. Layers feature in each of the crystal structures and are stabilized by substantial hydrogen-bonding interactions. Compound (1) crystallizes as a hemi-hydrate in the triclinic space group P-1 with a = 8.667(5) Å, b = 11.421(7) Å, c = 12.954(8) Å, α = 78.330(10)°, β = 84.553(10)°, γ = 75.510(9)°, and Z = 4. Compound (2) crystallizes in the monoclinic space group P21/c with a = 10.740(3) Å, b = 21.487(6) Å, c = 14.914(4) Å, β = 95.014(5)°, and Z = 12.
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| 14. |
- Rydfjord, Jonas, et al.
(författare)
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Decarboxylative Palladium(II)-Catalyzed Synthesis of Aryl Amidines from Aryl Carboxylic Acids : Development and Mechanistic Investigation
- 2013
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Ingår i: Chemistry - A European Journal. - : Wiley. - 0947-6539 .- 1521-3765. ; 19:41, s. 13803-13810
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Tidskriftsartikel (refereegranskat)abstract
- A fast and convenient synthesis of aryl amidines starting from carboxylic acids and cyanamides is reported. The reaction was achieved by palladium(II)-catalysis in a one-step microwave protocol using [Pd(O2CCF3)(2)], 6-methyl-2,2-bipyridyl and trifluoroacetic acid (TFA) in N-methylpyrrolidinone (NMP), providing the corresponding aryl amidines in moderate to excellent yields. The protocol is very robust with regards to the cyanamide coupling partner but requires electron-rich ortho-substituted aryl carboxylic acids. Mechanistic insight was provided by a DFT investigation and direct ESI-MS studies of the reaction. The results of the DFT study correlated well with the experimental findings and, together with the ESI-MS study, support the suggested mechanism. Furthermore, a scale-out (scale-up) was performed with a non-resonant microwave continuous-flow system, achieving a maximum throughput of 11mmolh(-1) by using a glass reactor with an inner diameter of 3mm at a flow rate of 1mLmin(-1).
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| 15. |
- Schembri, Luke S, et al.
(författare)
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A Base-Free, Low Temperature Click and Release Reaction for the In Situ Generation of Diazomethane
- 2023
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Ingår i: Advanced Synthesis and Catalysis. - : Wiley-Blackwell. - 1615-4150 .- 1615-4169. ; 365:11, s. 1839-1845
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Tidskriftsartikel (refereegranskat)abstract
- Diazomethane is a powerful reagent for numerous chemical reactions such as esterifications and the homologation of carboxylic acids. Unfortunately, the synthetic utility of diazomethane is severely limited by its toxicity and highly explosive nature. Diazald((R)) is typically used for ex situ synthesis, however it requires cumbersome and hazardous transfer of diazomethane from a caustic aqueous phase to the reaction medium. Herein, we present a low temperature and base-free insitu synthesis of diazomethane via a "click and release" reaction between an enamine and sulfonyl azide. Its utility is exemplified by the synthesis of diverse methyl esters in yields of up to 93%. Moreover, diazoketone synthesis from insitu generated diazomethane and acid chlorides was demonstrated for the first time. Finally, trideuteromethylation was achieved using acetone-d(6) as the deuterium source. We anticipate that this method will enable the safer use of diazomethane in organic synthesis and drug discovery programs.
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| 16. |
- Schembri, Luke S, et al.
(författare)
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Palladium(0)-Catalyzed Carbonylative Synthesis of N-Acylsulfonamides via Regioselective Acylation
- 2019
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Ingår i: Journal of Organic Chemistry. - : American Chemical Society (ACS). - 0022-3263 .- 1520-6904. ; 84:11, s. 6970-6981
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Tidskriftsartikel (refereegranskat)abstract
- N-Acylsulfonamides represent an important bioisostere of carboxylic acids that allow for greater molecular elaboration and enhanced hydrogen bonding capabilities. Herein, we present a mild and convenient palladium(0)-catalyzed synthesis of N-acylsulfonamides via the carbonylative coupling of sulfonyl azides and electron-rich heterocycles. The reaction proceeds via in situ generation of a sulfonyl isocyanate followed by regioselective acylation of an indole or pyrrole nucleophile. This approach has been used to synthesize 34 indole- and pyrrole-substituted N-acylsulfonamides in yields of up to 95%. Importantly, this process is ligand-free and compatible with an ex situ solid CO source and requires only slightly elevated temperatures, making it a highly attractive method for the preparation of this important class of compounds. This study further investigated the possibility of labeling N-acylsulfonamides with carbon-11 to facilitate biological evaluation and in vivo studies with positron emission tomography.
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| 17. |
- Ye, Sofie, et al.
(författare)
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Turning Information Dissipation into Dissemination : Instagram as a Communication Enhancing Tool during the COVID-19 Pandemic and Beyond
- 2020
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Ingår i: Journal of Chemical Education. - : AMER CHEMICAL SOC. - 0021-9584 .- 1938-1328. ; 97:9, s. 3217-3222
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Tidskriftsartikel (refereegranskat)abstract
- In the wake of the coronavirus disease 2019 (COVID-19) pandemic, staff and students at universities worldwide were forced to swiftly adapt to distance learning in order to continue with tertiary education. One of the main challenges we encountered during this period was a marked disconnect between staff and students, leading to lower motivation and engagement by both parties. To address this issue, we explored the social media platform Instagram as an interactive communication channel to engage first-year pharmacy students during an introductory organic chemistry course. This led to the development of @kemipilot, an open Instagram account where student questions were fielded and answered by creating educational images and videos. Despite being a small-scale study, the overwhelmingly positive student response, as well as comparisons between Instagram and the university student forum, suggest that Instagram may be a useful pedagogical tool to complement existing distance learning platforms, even beyond the COVID-19 pandemic.
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| 18. |
- Åkerbladh, Linda, et al.
(författare)
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Palladium(0)-Catalyzed Carbonylative One-Pot Synthesis of N-Acylguanidines
- 2017
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Ingår i: Journal of Organic Chemistry. - : American Chemical Society (ACS). - 0022-3263 .- 1520-6904. ; 82:23, s. 12520-12529
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Tidskriftsartikel (refereegranskat)abstract
- A convenient synthetic strategy toward N-acylguanidines via a sequential one-pot multicomponent carbonylation/amination reaction has been developed. The compounds were readily obtained via an N-cyanobenzamide intermediate formed from the Pd(0)-catalyzed carbonylative coupling of cyanamide and aryl iodides or bromides. Subsequent amination with a large variety of amines provided the final N-acylguanidines, with the overall formation of one C-C and two C-N bonds, in moderate to excellent yields. The substrate scope was found to be wide and the methodology was used to produce over 50 compounds, including 29 novel molecules. Furthermore, three separate nitrogen-containing heterocycles were prepared from the N-acylguanidines synthesized using the developed multicomponent, carbonylative method.
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| 19. |
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| 20. |
- Abdel-Hamid, Mohammed K, et al.
(författare)
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1,8-Naphthalimide derivatives : new leads against dynamin I GTPase activity.
- 2015
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Ingår i: Organic and biomolecular chemistry. - : Royal Society of Chemistry (RSC). - 1477-0520 .- 1477-0539. ; 13:29
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Tidskriftsartikel (refereegranskat)abstract
- Fragment-based in silico screening against dynamin I (dynI) GTPase activity identified the 1,8-naphthalimide framework as a potential scaffold for the design of new inhibitors targeting the GTP binding pocket of dynI. Structure-based design, synthesis and subsequent optimization resulted in the development of a library of 1,8-naphthalimide derivatives, called the Naphthaladyn™ series, with compounds 23 and 29 being the most active (IC50 of 19.1 ± 0.3 and 18.5 ± 1.7 μM respectively). Compound 29 showed effective inhibition of clathrin-mediated endocytosis (IC50(CME) 66 μM). The results introduce 29 as an optimised GTP-competitive lead Naphthaladyn™ compound for the further development of naphthalimide-based dynI GTPase inhibitors.
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| 21. |
- Adeyemi, Ahmed, 1986-
(författare)
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Palladium(0)-Catalyzed Synthesis of Spirocycles and Supercritical Chemistry using a Resistively Heated Flow Reactor
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This doctoral thesis focusses on an effective and selective approach to the synthesis of spirocycles using palladium(0)-catalyzed Mizoroki-Heck reactions. In addition, selective and efficient chemistry was highlighted by the design and evaluation of a novel resistively heated system for continuous flow (CF) synthesis for high-temperature and high-pressure applications.Paper I described the design and evaluation of a novel resistively heated CF system. The design of a low-cost, simple, robust, and effective CF system involving a resistively heated steel reactor capable of delivering 400 °C and 200 bar was reported. The reactor was evaluated with esterification, transesterification and direct carboxylic acid to nitrile conversions using supercritical ethanol, methanol and acetonitrile respectively. Diels-Alder reactions under neat conditions were also carried out at high temperature and pressure.Paper II reported the synthesis of spirooxindoles by a selective application of the palladium(0)-catalyzed Mizoroki-Heck spirocyclization. The precursors for the reaction were synthesized by coupling 2-iodoanilines with esters derived from enantiomerically pure (+)-Vince lactam decorated with the bulky, directing 2,5-dimethylpyrrole protecting group. Ten different spirooxindoles were reported with good yields and high regio- and stereoselectivity. Functionalization of a synthesized spirooxindole was done by a palladium(0)-catalyzed alkoxycarbonylation, followed by selective deprotections.In Paper III, ether precursors were synthesized from (+)-Vince lactam, via a Mitsunobu reaction with the corresponding iodophenols. The precursors were later subjected to conditions for intramolecular Mizoroki-Heck reaction. Overall, 12 spiroethers were synthesized in useable yields, regioselectivity up to 98% and with excellent diastereoselectivity (d.e.>98%). Further functionalization to mono-protected rigidified amino acids was also demonstrated.
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| 22. |
- Adeyemi, Ahmed, et al.
(författare)
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Regio- and Stereoselective Synthesis of Allylic Spiroethers (Spirobenzofuranes) via an Intramolecular Mizoroki-Heck Reaction
- 2020
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Ingår i: Journal of Organic Chemistry. - : American Chemical Society (ACS). - 0022-3263 .- 1520-6904. ; 85:12, s. 7648-7657
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Tidskriftsartikel (refereegranskat)abstract
- The palladium(0)-catalyzed intramolecular annulation of 12 1,3-disubstituted cyclopentenes, derived from (+)-vincelactam, resulted in 5-exo cyclizations which furnished a series of 2,5-dimethyl-14(3R,4'S)-2H-spiro[benzofuran-3,1'-cyclopentan]2'-en-4'-yl)-1H-pyrroles in excellent diastereoselectivities and useful isolated yields. The double bond migration process that followed the arylpalladium insertion was controlled by a fine-tuning of the reaction system, which provided regioselectivities of up to 98:2. The selective Mizoroki-Heck reaction was used as the key transformation for preparing two new spirocyclic monoprotected amino acids as single stereoisomers.
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| 23. |
- 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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| 24. |
- Bokale-Shivale, Suvarna, et al.
(författare)
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Synthesis of substituted 3,4-dihydroquinazolinones via a metal free Leuckart-Wallach type reaction
- 2021
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Ingår i: RSC Advances. - : Royal Society of Chemistry. - 2046-2069. ; 11:1, s. 349-353
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Tidskriftsartikel (refereegranskat)abstract
- The 3,4-dihydroquinazolinone (DHQ) moiety is a highly valued scaffold in medicinal chemistry due to the vast number of biologically-active compounds based on this core structure. Current synthetic methods to access these compounds are limited in terms of diversity and flexibility and often require the use of toxic reagents or expensive transition-metal catalysts. Herein, we describe the discovery and development of a novel cascade cyclization/Leuckart–Wallach type strategy to prepare substituted DHQs in a modular and efficient process using readily-available starting materials. Notably, the reaction requires only the addition of formic acid or acetic acid/formic acid and produces H2O, CO2 and methanol as the sole reaction byproducts. Overall, the reaction provides an attractive entry point into this important class of compounds and could even be extended to isotopic labelling via the site-selective incorporation of a deuterium atom.
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| 25. |
- Cheung, Pierre, et al.
(författare)
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[18F]MK-7246 for Positron Emission Tomography Imaging of the Beta-Cell Surface Marker GPR44
- 2023
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Ingår i: Pharmaceutics. - : MDPI. - 1999-4923. ; 15:2
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Tidskriftsartikel (refereegranskat)abstract
- The progressive loss of beta-cell mass is a hallmark of diabetes and has been suggested as a complementary approach to studying the progression of diabetes in contrast to the beta-cell function. Non-invasive nuclear medicinal imaging techniques such as Positron Emission Tomography using radiation emitting tracers have thus been suggested as more viable methodologies to visualize and quantify the beta-cell mass with sufficient sensitivity. The transmembrane G protein-coupled receptor GPR44 has been identified as a biomarker for monitoring beta-cell mass. MK-7246 is a GPR44 antagonist that selectively binds to GPR44 with high affinity and good pharmacokinetic properties. Here, we present the synthesis of MK-7246, radiolabeled with the positron emitter fluorine-18 for preclinical evaluation using cell lines, mice, rats and human pancreatic cells. Here, we have described a synthesis and radiolabeling method for producing [18F]MK-7246 and its precursor compound. Preclinical assessments demonstrated the strong affinity and selectivity of [18F]MK-7246 towards GPR44. Additionally, [18F]MK-7246 exhibited excellent metabolic stability, a fast clearance profile from blood and tissues, qualifying it as a promising radioactive probe for GPR44-directed PET imaging.
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| 26. |
- Cheung, Pierre, et al.
(författare)
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PET Imaging of GPR44 by Antagonist [C-11]MK-7246 in Pigs
- 2021
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Ingår i: Biomedicines. - : MDPI. - 2227-9059. ; 9:4
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Tidskriftsartikel (refereegranskat)abstract
- A validated imaging marker for beta-cell mass would improve understanding of diabetes etiology and enable new strategies in therapy development. We previously identified the membrane-spanning protein GPR44 as highly expressed and specific to the beta cells of the pancreas. The selective GPR44 antagonist MK-7246 was radiolabeled with carbon-11 and the resulting positron-emission tomography (PET) tracer [C-11]MK-7246 was evaluated in a pig model and in vitro cell lines. The [C-11]MK-7246 compound demonstrated mainly hepatobiliary excretion with a clearly defined pancreas, no spillover from adjacent tissues, and pancreatic binding similar in magnitude to the previously evaluated GPR44 radioligand [C-11]AZ12204657. The binding could be blocked by preadministration of nonradioactive MK-7246, indicating a receptor-binding mechanism. [C-11]MK-7246 showed strong potential as a PET ligand candidate for visualization of beta-cell mass (BCM) and clinical translation of this methodology is ongoing.
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| 27. |
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| 28. |
- Chow, Shiao Y., et al.
(författare)
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Low-Pressure Radical C-11-Aminocarbonylation of Alkyl Iodides through Thermal Initiation
- 2016
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Ingår i: European Journal of Organic Chemistry. - : Wiley. - 1434-193X .- 1099-0690. ; :36, s. 5980-5989
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Tidskriftsartikel (refereegranskat)abstract
- A radical C-11-aminocarbonylation protocol characterized by excellent substrate compatibility was developed to transform alkyl iodides into C-11-labelled amides, including the 11-HSD1 inhibitor [carbonyl-C-11]adamantan-1-yl(piperidin-1-yl)methanone. This protocol serves as a complementary extension of palladium-mediated C-11-aminocarbonylation, which is limited to the preparation of C-11-labelled compounds lacking beta-hydrogen atoms. The use of AIBN as a radical initiator and a low-pressure xenon-[C-11]CO delivery unit represents a simple and convenient alternative to previous radical C-11-carbonylation methodologies burdened with the need for a proprietary high pressure reactor connected to a light source.
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| 29. |
- Chow, Shiao Y., et al.
(författare)
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Mild and Low-Pressure fac-Ir(ppy)3-Mediated Radical Aminocarbonylation of Unactivated Alkyl Iodides through Visible-Light Photoredox Catalysis
- 2016
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Ingår i: Chemistry - A European Journal. - : Wiley. - 0947-6539 .- 1521-3765. ; 22:27, s. 9155-9161
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Tidskriftsartikel (refereegranskat)abstract
- A novel, mild and facile preparation of alkyl amides from unactivated alkyl iodides employing a fac-Ir(ppy)(3)-catalyzed radical aminocarbonylation protocol has been developed. Using a two-chambered system, alkyl iodides, fac-Ir(ppy)(3), amines, reductants, and CO gas (released ex situ from Mo(CO)(6)), were combined and subjected to an initial radical reductive dehalogenation generating alkyl radicals, and a subsequent aminocarbonylation with amines affording a wide range of alkyl amides in moderate to excellent yields.
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| 30. |
- Chow, Shiao Y., et al.
(författare)
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Synthesis of N-Sulfonyl Amidines and Acyl Sulfonyl Ureas from Sulfonyl Azides, Carbon Monoxide, and Amides
- 2017
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Ingår i: Journal of Organic Chemistry. - : AMER CHEMICAL SOC. - 0022-3263 .- 1520-6904. ; 82:5, s. 2515-2522
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Tidskriftsartikel (refereegranskat)abstract
- A Pd-catalyzed and ligand-free carbonylation/cycloaddition/decarboxylation cascade synthesis of sulfonyl amidines from sulfonyl azides and substituted amides at low CO pressure is reported. The reaction proceeds via an initial Pd-catalyzed carbonylative generation of sulfonyl isocyanates from sulfonyl azides, followed by a [2 + 2] cycloaddition with amides and subsequent decarboxylation, which liberates the desired sulfonyl amidines, generating N-2 and CO2 as the only reaction byproducts. Using this simple protocol, a diverse range of sulfonyl amidines was obtained in moderate to excellent yields. In addition, the reaction can also be directed through a more conventional amidocarbonylation pathway by employing N-monosubstituted amide nucleophiles to afford acyl sulfonyl ureas in good yields.
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| 31. |
- De Rosa, Maria, et al.
(författare)
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Syntheses of new tuberculosis inhibitors promoted by microwave irradiation
- 2014
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Ingår i: Upsala Journal of Medical Sciences. - : Uppsala Medical Society. - 0300-9734 .- 2000-1967. ; 119:2, s. 181-191
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Forskningsöversikt (refereegranskat)abstract
- Tuberculosis (TB) represents a major public health problem. The growing number of (extensively) multi-drug resistance cases indicates that there is an urgent need for discovery of new anti-TB entities, addressed towards new and specific targets, and continuous development of fast and efficient synthetic strategies to access them easily. Microwave-assisted chemistry is well suited for small-scale laboratory synthetic work, allowing full control of reaction conditions, such as temperature, pressure, and time. Microwave-assisted high-speed organic synthesis is especially useful in the lead optimization phase of drug discovery. To illustrate the advantages of modern microwave heating technology, we herein describe applications and approaches that have been useful for the synthesis of new drug-like anti-TB compounds.
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| 32. |
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| 33. |
- 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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| 34. |
- Gising, Johan, et al.
(författare)
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Microwave-assisted synthesis of anti-tuberculosis, HIV and hepatitis C agents
- 2014
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Ingår i: Microwaves in Drug Discovery and Development. - Unitec House, 2 Albert Place, London N3 1QB, UK : Future Medicine. - 9781910419298 - 9781910419311 ; , s. 34-54
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Bokkapitel (refereegranskat)abstract
- Microwave heating technology is ideally suited to small-scale discovery chemistry applications, as it allows for full reaction control, rapid (super)heating, short reaction times, high safety and rapid feedback. These unique properties offer unparalleled opportunities for medicinal chemists to speed up the lead optimization process in early drug discovery. To illustrate these advantages, we herein describe a number of recent applications of dedicated microwave instrumentation in the synthesis of small molecules targeting three of the most prevalent infectious diseases: tuberculosis, HIV/AIDS and hepatitis C.
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| 35. |
- Gising, Johan, et al.
(författare)
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Microwave-assisted synthesis of small molecules targeting the infectious diseases tuberculosis, HIV/AIDS, malaria and hepatitis C
- 2012
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Ingår i: Organic and biomolecular chemistry. - : Royal Society of Chemistry (RSC). - 1477-0520 .- 1477-0539. ; 10:14, s. 2713-2729
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Tidskriftsartikel (refereegranskat)abstract
- The unique properties of microwave in situ heating offer unparalleled opportunities for medicinal chemists to speed up lead optimisation processes in early drug discovery. The technology is ideal for small-scale discovery chemistry because it allows full reaction control, short reaction times, high safety and rapid feedback. To illustrate these advantages, we herein describe applications and approaches in the synthesis of small molecules to combat four of the most prevalent infectious diseases; tuberculosis, HIV/AIDS, malaria and hepatitis C, using dedicated microwave instrumentation.
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| 36. |
- Hartmann, Rafael
(författare)
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A Chemical Approach Toward the Therapeutic Optimization of Cytotoxic Bioconjugates
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The delivery of cytotoxicity to specific cells was recognized to be the key to the effective, chemical treatment of infectious and neoplastic diseases well over a century ago. In the context of oncology, the primary therapeutic challenge is the distinction between healthy and pathological cells despite their pronounced pheno- and genotypic similarity. Bioconjugates, such as antibody-drug conjugates (ADCs), are equipped to solve the issue by virtue of their orthogonal make-up: A protein carrier (antibody) confers tumor selectivity, while a small molecule (“drug”) delivers cytotoxicity.The thesis at hand addresses the analytical challenges which are consequences of an ADC’s orthogonal structure. Paper I critically compares the available methods for the assessment of the stoichiometric ratio between antibody and drug (the drug-antibody ratio, DAR). It concludes with a series of recommendations aimed at entrants new to the field. Paper II introduces a novel method for the removal of small molecule impurities prior to mass-spectrometric analysis. Using the outlined procedure, it is possible to remove almost all potentially interferential buffer components while recovering approximately 90% of the analyte.Synthetic research lies at the thesis’s core. Paper III describes the design and biological evaluation of a series of novel cytotoxins (“azastatins”), whose total synthesis was accomplished in 22-23 steps. The compounds are highly potent inhibitors of tubulin polymerization and appear to only possess cellular permeability while protein-bound, thus eliminating the risk of unintended harm to healthy tissues. Moreover, unpublished research details an ultimately unsuccessful attempt at a solid-phase method for the synthesis of a peptide linker commonly used to attach cytotoxic drugs to antibodies. Satisfactory yields for the detachment of the target compounds from the resin were not achieved, which was rationalized based on pseudo-intramolecular, irreversible solid-phase reattachment. Paper IV introduces a novel methodology for the bioconjugation of small molecules to proteins by means of Wittig chemistry. The procedure afforded nine different conjugates of two different proteins in moderate to excellent yields and may allow for the subsequent functionalization of the newly generated, highly electron deficient alkenes. It is potentially applicable to the challenging generation of protein heterodimers.
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| 37. |
- Hartmann, Rafael, et al.
(författare)
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Rational Design of Azastatin as a Potential ADC Payload with Reduced Bystander Killing.
- 2020
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Ingår i: ChemMedChem. - : Wiley. - 1860-7179 .- 1860-7187. ; 15:24, s. 2500-2512
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Tidskriftsartikel (refereegranskat)abstract
- Auristatins are a class of ultrapotent microtubule inhibitors, whose growing clinical popularity in oncology is based upon their use as payloads in antibody-drug conjugates (ADCs). The most widely utilized auristatin, MMAE, has however been shown to cause apoptosis in non-pathological cells proximal to the tumour ("bystander killing"). Herein, we introduce azastatins, a new class of auristatin derivatives encompassing a side chain amine for antibody conjugation. The synthesis of Cbz-azastatin methyl ester, which included the C2-elongation and diastereoselective reduction of two proteinogenic amino acids as key transformations, was accomplished in 22 steps and 0.76 % overall yield. While Cbz-protected azastatin methyl ester (0.13-3.0 nM) inhibited proliferation more potently than MMAE (0.47-6.5 nM), removal of the Cbz-group yielded dramatically increased IC50 -values (9.8-170 nM). We attribute the reduced apparent cytotoxicity of the deprotected azastatin methyl esters to a lack of membrane permeability. These results clearly establish the azastatins as a novel class of cytotoxic payloads ideally suited for use in next-generation ADC development.
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| 38. |
- Hartmann, Rafael W., et al.
(författare)
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The Wittig Bioconjugation of Maleimide Derived, Water Soluble Phosphonium Ylides to Aldehyde-Tagged Proteins
- 2021
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Ingår i: Organic and biomolecular chemistry. - : Royal Society of Chemistry. - 1477-0520 .- 1477-0539. ; 19:47, s. 10417-10423
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Tidskriftsartikel (refereegranskat)abstract
- Herein we disclose the transformation of maleimides into water-soluble tris(2-carboxyethyl)phosphonium ylides and their subsequent application in the bioconjugation of protein- and peptide-linked aldehydes. The new entry into Wittig bioconjugate chemistry proceeds under mild conditions and relies on highly water soluble reagents, which are likely already part of most biochemists’ inventory.
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| 39. |
- Hill, Timothy A., et al.
(författare)
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Iminochromene Inhibitors of Dynamins I and II GTPase Activity and Endocytosis
- 2010
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Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society (ACS). - 0022-2623 .- 1520-4804. ; 53:10, s. 4094-4102
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Tidskriftsartikel (refereegranskat)abstract
- Herein we report the synthesis of discrete iminochromene (“iminodyn”) libraries (14−38) as potential inhibitors of dynamin GTPase. Thirteen iminodyns were active (IC50 values of 260 nM to 100 μM), with N,N-(ethane-1,2-diyl)bis(7,8-dihydroxy-2-iminochromene-3-carboxamide) (17), N,N-(ethane-1,2-diyl)bis(7,8-dihydroxy-2-iminochromene-3-carboxamide) (22), and N,N-(ethane-1,2-diyl)bis(7,8-dihydroxy-2-iminochromene-3-carboxamide) (23) (IC50 values of 330 ± 70, 450 ± 50, and 260 ± 80 nM, respectively) being the most potent. Five of the most potent iminodyns all inhibited dynamins I and II approximately equally. Iminodyn-22 displayed uncompetitive inhibition with respect to GTP. Selected iminodyns were evaluated for their ability to block receptor mediated endocytosis (RME, mediated by dynamin II) and synaptic vesicle endocytosis (SVE, mediated by dynamin I), with 17 showing no activity while 22 returned RME and SVE IC50 values of 10.7 ± 4.5 and 99.5 ± 1.7 μM, respectively. The iminodyns reported herein represent a new chemical class of the first nanomolar potent dynamin inhibitors that are also effective endocytosis inhibitors.
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| 40. |
- Hill, Timothy A, et al.
(författare)
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Inhibition of dynamin mediated endocytosis by the dynoles : synthesis and functional activity of a family of indoles
- 2009
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Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society (ACS). - 0022-2623 .- 1520-4804. ; 52:12, s. 3762-3773
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Tidskriftsartikel (refereegranskat)abstract
- Screening identified two bisindolylmaleimides as 100 microM inhibitors of the GTPase activity of dynamin I. Focused library approaches allowed development of indole-based dynamin inhibitors called dynoles. 100-Fold in vitro enhancement of potency was noted with the best inhibitor, 2-cyano-3-(1-(2-(dimethylamino)ethyl)-1H-indol-3-yl)-N-octylacrylamide (dynole 34-2), a 1.3 +/- 0.3 microM dynamin I inhibitor. Dynole 34-2 potently inhibited receptor mediated endocytosis (RME) internalization of Texas red-transferrin. The rank order of potency for a variety of dynole analogues on RME in U2OS cells matched their rank order for dynamin inhibition, suggesting that the mechanism of inhibition is via dynamin. Dynoles are the most active dynamin I inhibitors reported for in vitro or RME evaluations. Dynole 34-2 is 15-fold more active than dynasore against dynamin I and 6-fold more active against dynamin mediated RME (IC(50) approximately 15 microM; RME IC(50) approximately 80 microM). The dynoles represent a new series of tools to better probe endocytosis and dynamin-mediated trafficking events in a variety of cells.
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| 41. |
- Hill, Timothy A, et al.
(författare)
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Long chain amines and long chain ammonium salts as novel inhibitors of dynamin GTPase activity.
- 2004
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Ingår i: Bioorganic & Medicinal Chemistry Letters. - : Elsevier BV. - 0960-894X .- 1464-3405. ; 14:12
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Tidskriftsartikel (refereegranskat)abstract
- We examined a number of ligands with the view of inhibiting the GTPase activity of dynamin. Dynamin contains a pleckstrin homology (PH) domain that interacts with lipids. We report a series of simple lipid-like molecules that display moderate inhibitory activity. Inhibitory activity is linked to chain length and quaternarization of the terminal amine. A change in the counterion, Cl versus Br or I, had little effect on potency. However, introduction of a hydrophobic collar proximal to the charged site was beneficial to dynamin GTPase inhibitory action. The most potent compound was myristoyl trimethyl ammonium bromide (MTMAB, IC(50) 3.15 microM).
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| 42. |
- Hill, Timothy, et al.
(författare)
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Small molecule inhibitors of dynamin I GTPase activity : development of dimeric tyrphostins.
- 2005
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Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society (ACS). - 0022-2623 .- 1520-4804. ; 48:24
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Tidskriftsartikel (refereegranskat)abstract
- Dynamin I is a GTPase enzyme required for endocytosis and is an excellent target for the design of potential endocytosis inhibitors. Screening of a library of tyrphostins, in our laboratory, against the GTPase activity of dynamin I gave rise to a microM potent lead, 2-cyano-3-(3,4-dihydroxyphenyl)thioacrylamide (1, IC50 70 microM). Our initial investigations suggested that only the dimeric form of 1 displayed dynamin I GTPase inhibitory activity. Subsequent synthetic iterations were based on dimeric analogues and afforded a number of small molecules, low microM potent, inhibitors of dynamin I GTPase, in particular, symmetrical analogues with a minimum of two free phenolic -OHs: catechol-acrylamide (9) (IC50= 5.1 +/- 0.6 microM), its 3,4,5-trihydroxy congener (10) (IC50= 1.7 +/- 0.2 microM), and the corresponding 3-methyl ether (11) (IC50= 9 +/- 3 microM). Increasing the length of the central alkyl spacer from ethyl to propyl (22-24) afforded essentially identical activity with IC50's of 1.7 +/- 0.2, 1.7 +/- 0.2, and 5 +/- 1 microM, respectively. No decrease in activity was noted until the introduction of a hexyl spacer. Our studies highlight the requirement for two free amido NHs with neither the mono-N-methyl (86) nor the bis-N-methyl (87) analogues inhibiting dynamin I GTPase. A similar effect was noted for the removal of the nitrile moieties. However, modest potency was observed with the corresponding ester analogues of 9-11: ethyl ester (90), propyl ester (91), and butyl ester (92), with IC50's of 42 +/- 3, 38 +/- 2, and 61 +/- 2 microM, respectively. Our studies reveal the most potent and promising dynamin I GTPase inhibitor in this series as (22), which is also known as BisT.
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| 43. |
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| 44. |
- Lehmann, Fredrik, et al.
(författare)
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A versatile new synthetic route to 1N-hydroxyindazoles
- 2009
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Ingår i: Organic Letters. - : American Chemical Society (ACS). - 1523-7060 .- 1523-7052. ; 11:21, s. 5078-5081
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Tidskriftsartikel (refereegranskat)abstract
- A new and versatile cyclization reaction affording rare 1N-hydroxyindazoles is presented. Treatment of 2-nitrobenzylamines with methanolic sodium hydroxide furnishes 1N-hydroxyindazoles regioselectively and in high yield. The reaction tolerates a range of functional groups and electronic effects.
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| 45. |
- MacGregor, Kylie A, et al.
(författare)
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Development of quinone analogues as dynamin GTPase inhibitors
- 2014
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Ingår i: European Journal of Medicinal Chemistry. - : Elsevier BV. - 0223-5234 .- 1768-3254. ; 85, s. 191-206
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Tidskriftsartikel (refereegranskat)abstract
- Virtual screening of the ChemDiversity and ChemBridge compound databases against dynamin I (dynI) GTPase activity identified 2,5-bis-(benzylamino)-1,4-benzoquinone 1 as a 273 ± 106 μM inhibitor. In silico lead optimization and focused library-led synthesis resulted in the development of four discrete benzoquinone/naphthoquinone based compound libraries comprising 54 compounds in total. Sixteen analogues were more potent than lead 1, with 2,5-bis-(4-hydroxyanilino)-1,4-benzoquinone (45) and 2,5-bis(4-carboxyanilino)-1,4-benzoquinone (49) the most active with IC50 values of 11.1 ± 3.6 and 10.6 ± 1.6 μM respectively. Molecular modelling suggested a number of hydrogen bonding and hydrophobic interactions were involved in stabilization of 49 within the dynI GTP binding site. Six of the most active inhibitors were evaluated for potential inhibition of clathrin-mediated endocytosis (CME). Quinone 45 was the most effective CME inhibitor with an IC50(CME) of 36 ± 16 μM.
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| 46. |
- Mane, Rajendra S, et al.
(författare)
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Palladium-Catalyzed Carbonylative Synthesis of N-Cyanobenzamides from Aryl Iodides/Bromides and Cyanamide
- 2013
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Ingår i: Tetrahedron Letters. - : Elsevier BV. - 0040-4039 .- 1359-8562. ; 54:50, s. 6912-6915
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Tidskriftsartikel (refereegranskat)abstract
- A novel and convenient protocol for the synthesis of N-cyanobenzamides starting from readily available aryl halides and cyanamide via palladium-catalyzed aminocarbonylation has been developed. The protocol utilizes Mo(CO)6 as the CO source or CO(gas) and affords the desired N-cyanobenzamides in moderate to good yields.
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| 47. |
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| 48. |
- McGeachie, Andrew B, et al.
(författare)
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Pyrimidyn Compounds : Dual-Action Small Molecule Pyrimidine-Based Dynamin Inhibitors
- 2013
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Ingår i: ACS Chemical Biology. - : American Chemical Society (ACS). - 1554-8929 .- 1554-8937. ; 8:7, s. 1507-1518
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Tidskriftsartikel (refereegranskat)abstract
- Dynamin is required for clathrin-mediated endocytosis (CME). Its GTPase activity is stimulated by phospholipid binding to its PH domain, which induces helical oligomerization. We have designed a series of novel pyrimidine-based "Pyrimidyn" compounds that inhibit the lipid-stimulated GTPase activity of full length dynamin I and II with similar potency. The most potent analogue, Pyrimidyn 7, has an IC50 of 1.1 μM for dynamin I and 1.8 μM for dynamin II, making it among the most potent dynamin inhibitors identified to date. We investigated the mechanism of action of the Pyrimidyn compounds in detail by examining the kinetics of Pyrimidyn 7 inhibition of dynamin. The compound competitively inhibits both GTP and phospholipid interactions with dynamin I. While both mechanisms of action have been previously observed separately, this is the first inhibitor series to incorporate both and thereby to target two distinct domains of dynamin. Pyrimidyn 6 and 7 reversibly inhibit CME of both transferrin and EGF in a number of non-neuronal cell lines as well as inhibiting synaptic vesicle endocytosis (SVE) in nerve terminals. Therefore, Pyrimidyn compounds block endocytosis by directly competing with GTP and lipid binding to dynamin, limiting both the recruitment of dynamin to membranes and its activation. This dual mode of action provides an important new tool for molecular dissection of dynamin's role in endocytosis.
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| 49. |
- Motwani, Hitesh V., et al.
(författare)
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Aspartic protease inhibitors containing tertiary alcohol transition-state mimics
- 2014
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Ingår i: European Journal of Medicinal Chemistry. - : Elsevier BV. - 0223-5234 .- 1768-3254. ; 90, s. 462-490
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Forskningsöversikt (refereegranskat)abstract
- Aspartic proteases (APs) are a class of enzymes engaged in the proteolytic digestion of peptide substrates. APs play important roles in physiological and infectious pathways, making them plausible drug targets. For instance in the treatment of HIV infections, access to an efficient combination of protease and reverse transcriptase inhibitors have changed a terminal illness to a chronic but manageable disease. However, the benefits have been limited due to the emergence of drug resistant viral strains, poor pharmacokinetic properties of peptidomimetic inhibitors and adverse effects associated with the treatment. In the 1980s, D. Rich and co-workers proposed a novel strategy for the development of AP inhibitors by replacing the secondary hydroxyl group with a tertiary alcohol as part of the transition state (TS) mimicking moiety. This strategy has been extensively explored over the last decade with a common belief that masking of the polar group, e.g. by intramolecular hydrogen bonding, has the potential to enhance transcellular transport. This is the first review presenting the advances of AP inhibitors comprising a tertiary hydroxyl group. The inhibitors have been classified into different tert-hydroxy TS mimics and their design strategies, synthesis, biological activities, structure-activity-relationships and X-ray structures are discussed.
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| 50. |
- Mowbray, Sherry L, et al.
(författare)
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Inhibition of Glutamine Synthetase : A Potential Drug Target in Mycobacterium tuberculosis
- 2014
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Ingår i: Molecules. - : MDPI AG. - 1431-5157 .- 1420-3049. ; 19:9, s. 13161-13176
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Forskningsöversikt (refereegranskat)abstract
- Tuberculosis is an infectious disease caused by Mycobacterium tuberculosis. Globally, tuberculosis is second only to AIDS in mortality and the disease is responsible for over 1.3 million deaths each year. The impractically long treatment schedules (generally 6-9 months) and unpleasant side effects of the current drugs often lead to poor patient compliance, which in turn has resulted in the emergence of multi-, extensively- and totally-drug resistant strains. The development of new classes of anti-tuberculosis drugs and new drug targets is of global importance, since attacking the bacterium using multiple strategies provides the best means to prevent resistance. This review presents an overview of the various strategies and compounds utilized to inhibit glutamine synthetase, a promising target for the development of drugs for TB therapy.
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