| 1. |
- Adolfsson, Dan E., 1989-
(författare)
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Synthesis of Ring-fused Peptidomimetics : Interacting with Amyloid Fibrils
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Parkinson's and Alzheimer's disease are the two most common neurological disorders in humans. Both conditions involve progressive death of neurons in the central nervous system, decline in bodily functions and eventually (and invariably), death. So far, no cure exists and the available treatments can only ease symptoms. Despite substantial investments in research, the biomolecular processes are still far from fully understood. However, both diseases are associated with formation of fibrillar protein aggregates called amyloid deposits. Whereas Alzheimer’s disease involves aggregation of the Tau and Amyloid β proteins, α-Synuclein fibrilization plays a key role in Parkinson's disease. Although they are chemically distinct, the deposits consist of protein fibres with similar morphology and fold. Small molecules, such as the thiazoline fused 2-pyridones herein presented, can interfere with the formation of amyloid fibres, or bind to them. Besides having potential for diagnostication and treatment, such small molecules constitute valuable tool compounds in future research, to unravel the mechanisms of amyloid formation and pathology. The first step towards successful treatment, diagnostication and prevention of Alzheimer's and Parkinson's disease is understanding the causes and underlying mechanisms better. This thesis narrates the synthesis and development of novel chemical structures: multi ring fused peptidomimetics with the ability to bind mature amyloid fibrils, consisting of α-Synuclein or Amyloid β. The first project (articles I, III and VI) describes method development for the extension of bicyclic thiazolino 2-pyrdiones by fusion with aromatic nitrogen heterocycles, which enables the desired amyloid binding properties. Derivatisations of the newly generated central scaffold, and variation of the multiple attached substituents, were subsequently performed in efforts to improve binding strength and solubility, and gain selectivity towards certain fibrils. One of the most promising amyloid fibril binders was evaluated in a human cell line and in mice, and found to be protective against accelerator induced neurotoxicity. One pyrimidine fused compound moreover indicated potent inhibition of Amyloid b aggregation. The second project (articles II, IV and V) focuses on development of methods to modify the thiazoline ring. Ring opening induced by electrophiles generates N-alkenyl 2-pyridones but decreases amyloid binding potency. Introduction of a cyclobutane moiety fused with the thiazoline ring is better tolerated, and adds a terminal alkene moiety that can be exploited in future chemical modifications. Expansion of the five membered thiazoline ring to a six membered dihydrothiazine ring, equipped with a nitrophenyl substituent, provides compounds with enhanced fibril binding capacity, which further inhibits Amyloid β fibril formation in vitro. Taken together, the synthetic methodologies allow construction and late stage modification of complex fused heterocycles, with several points of variation. Thus, the developed methods may be of future value in our laboratories and elsewhere.
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| 2. |
- Ahmadpour, Doryaneh, 1973, et al.
(författare)
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Effect of MAPK Inhibitor on the Arsenite uptake by Aquaglyceroporin in Single Yeast Cells.
- 2013
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Ingår i: Optical Molecular Probes, Imaging and Drug Delivery.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Regulating arsenic uptake is imperative due to its carcinogenicity. Combining microfluidics, optical tweezers and fluorescence microscopy, the arsenite uptake by Fps1 using a selective kinase inhibitor is investigated using a single cell analysis platform.
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| 3. |
- Ahmadpour, Doryaneh, 1973, et al.
(författare)
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Inhibition of MAPK Hog1 Results in Increased Hsp104 Aggregate Formation Probably through Elevated Arsenite Influx into the Cells, an Approach with Numerous Potential Applications
- 2014
-
Ingår i: American Journal of Molecular Biology. - : Scientific Research Publishing, Inc.. - 2161-6620 .- 2161-6663. ; 4:2, s. 59-71
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Tidskriftsartikel (refereegranskat)abstract
- Arsenic is a highly toxic and carcinogenic metalloid widely dispersed in the environment, contaminating water and soil and accumulating in crops. Paradoxically, arsenic is also part of modern therapy and employed in treating numerous ailments and diseases. Hence, inventing strategies to tune cellular arsenic uptake based on purpose is striking. Here, we describe an approach in which the arsenite uptake can be increased using a MAPK inhibitor. Employing microfluidic flow chambers in combination with optical tweezers and fluorescent microscopy, we elevated the influx of arsenite into the yeast Saccharomyces cerevisiae cells following short-term treatment with a Hog1 kinase inhibitor. The increase in arsenite uptake was followed on arsenite triggered redistribution of a reporter protein, Hsp104-GFP, which was imaged over time. The effect was even more pronounced when the yeast mother and daughter cells were analyzed disjointedly, an opportunity provided owing to single-cell analysis. Our data firstly provide a strategy to increase arsenite uptake and secondly show that arsenite triggered aggregates, previously shown to be sites of damaged proteins, are distributed asymmetrically and less accumulated in daughter cells. Inventing approaches to tune arsenite uptake has a great value for its use in environmental as well as medical applications.
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| 4. |
- Alalam, Hanna, et al.
(författare)
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A Genetic Trap in Yeast for Inhibitors of SARS-CoV-2 Main Protease
- 2021
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Ingår i: MSYSTEMS. - 2379-5077. ; 6:6
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Tidskriftsartikel (refereegranskat)abstract
- The ongoing COVID-19 pandemic urges searches for antiviral agents that can block infection or ameliorate its symptoms. Using dissimilar search strategies for new antivirals will improve our overall chances of finding effective treatments. Here, we have established an experimental platform for screening of small molecule inhibitors of the SARS-CoV-2 main protease in Saccharomyces cerevisiae cells, genetically engineered to enhance cellular uptake of small molecules in the environment. The system consists of a fusion of the Escherichia coli toxin MazF and its antitoxin MazE, with insertion of a protease cleavage site in the linker peptide connecting the MazE and MazF moieties. Expression of the viral protease confers cleavage of the MazEF fusion, releasing the MazF toxin from its antitoxin, resulting in growth inhibition. In the presence of a small molecule inhibiting the protease, cleavage is blocked and the MazF toxin remains inhibited, promoting growth. The system thus allows positive selection for inhibitors. The engineered yeast strain is tagged with a fluorescent marker protein, allowing precise monitoring of its growth in the presence or absence of inhibitor. We detect an established main protease inhibitor by a robust growth increase, discernible down to 1 mM. The system is suitable for robotized large-scale screens. It allows in vivo evaluation of drug candidates and is rapidly adaptable for new variants of the protease with deviant site specificities. IMPORTANCE The COVID-19 pandemic may continue for several years before vaccination campaigns can put an end to it globally. Thus, the need for discovery of new antiviral drug candidates will remain. We have engineered a system in yeast cells for the detection of small molecule inhibitors of one attractive drug target of SARS-CoV-2, its main protease, which is required for viral replication. The ability to detect inhibitors in live cells brings the advantage that only compounds capable of entering the cell and remain stable there will score in the system. Moreover, because of its design in yeast cells, the system is rapidly adaptable for tuning the detection level and eventual modification of the protease cleavage site in the case of future mutant variants of the SARSCoV-2 main protease or even for other proteases.
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| 5. |
- Alao, John Patrick, 1973, et al.
(författare)
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Selective inhibition of RET mediated cell proliferation in vitro by the kinase inhibitor SPP86
- 2014
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Ingår i: BMC Cancer. - : BioMed Central. - 1471-2407. ; 14:853
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundThe RET tyrosine kinase receptor has emerged as a target in thyroid and endocrine resistant breast cancer. We previously reported the synthesis of kinase inhibitors with potent activity against RET. Herein, we have further investigated the effect of the lead compound SPP86 on RET mediated signaling and proliferation. Based on these observations, we hypothesized that SPP86 may be useful for studying the cellular activity of RET.MethodsWe compared the effects of SPP86 on RET-induced signaling and proliferation in thyroid cancer cell lines expressing RET-PTC1 (TPC1), or the activating mutations BRAFV600E (8505C) and RASG13R (C643). The effect of SPP86 on RET- induced phosphatidylinositide 3-kinases (PI3K)/Akt and MAPK pathway signaling and cell proliferation in MCF7 breast cancer cells was also investigated.ResultsSPP86 inhibited MAPK signaling and proliferation in RET/PTC1 expressing TPC1 but not 8505C or C643 cells. In TPC1 cells, the inhibition of RET phosphorylation required co-exposure to SPP86 and the focal adhesion kinase (FAK) inhibitor PF573228. In MCF7 cells, SPP86 inhibited RET- induced phosphatidylinositide 3-kinases (PI3K)/Akt and MAPK signaling and estrogen receptorα (ERα) phosphorylation, and inhibited proliferation to a similar degree as tamoxifen. Interestingly, SPP86 and PF573228 inhibited RET/PTC1 and GDNF- RET induced activation of Akt and MAPK signaling to a similar degree.ConclusionSPP86 selectively inhibits RET downstream signaling in RET/PTC1 but not BRAFV600E or RASG13R expressing cells, indicating that downstream kinases were not affected. SPP86 also inhibited RET signaling in MCF7 breast cancer cells. Additionally, RET- FAK crosstalk may play a key role in facilitating PTC1/RET and GDNF- RET induced activation of Akt and MAPK signaling in TPC1 and MCF7 cells.
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| 6. |
- Ankner, Tobias, 1976, et al.
(författare)
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KHMDS enhanced SmI(2)-mediated reformatsky type alpha-cyanation.
- 2010
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Ingår i: Organic letters. - : American Chemical Society (ACS). - 1523-7052 .- 1523-7060. ; 12:10, s. 2210-3
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Tidskriftsartikel (refereegranskat)abstract
- A novel combination of SmI(2), KHMDS, and TsCN can be utilized to introduce a cyano group into structurally diverse and highly sensitive 2-alkyl-chroman-4-ones. Subsequent oxidation allows the formed 2-alkyl-3-cyanochromones to be isolated in yields ranging from 49 to 77%. In addition, alpha-bromoketones and esters were found to undergo equally effective alpha-cyanation.
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| 7. |
- Axelsson, Linda, 1977-
(författare)
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Development of HIV-1 Protease Inhibitors and Palladium-Catalyzed Synthesis of Aryl Ketones and N-Allylbenzamides
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The use of palladium-catalyzed reactions to introduce new carbon-carbon bonds is a fundamental synthetic strategy that has been widely embraced due to its high chemo- and regioselectivity and functional group tolerance. In this context, Pd(0)-catalyzed aminocarbonylations using Mo(CO)6 instead of toxic and gaseous CO and with allylamine as the nucleophile were investigated. The aminocarbonylated product dominated over the Mizoroki-Heck product, and (hetero)aryl iodides, bromides and chlorides gave N-allylbenzamides in good yields.In this thesis improvements to an existing protocol for the Pd(II)-catalyzed synthesis of aryl ketones from five benzoic acids and a variety of nitriles are also presented. Addition of TFA improved the yields and employing THF as solvent enabled the use of solid nitriles, and the aryl ketones were isolated in good yields.The pandemic of HIV infection is one of the greatest public health issues of our time and approximately 35.3 million people worldwide are living with HIV. There are currently many drugs on the market targeting various parts of the viral reproduction cycle, but the problems of resistance warrant the search for new drugs. HIV-1 protease makes the virus mature into infectious particles. In this thesis a new type of HIV-1 protease inhibitor (PI) is presented, based on two of the PIs on the market, atazanavir and indinavir, but it has a tertiary alcohol, as well as a two-carbon tether between the quaternary carbon and the hydrazide β-nitrogen. A total of 25 new inhibitors were designed, synthesized and biologically evaluated, the best compound had an EC50 value of 3 nM.Based on this series a project aimed at synthesizing macrocycles spanning the P1-P3 area was initiated. Macrocycles often tend to have an improved affinity and metabolic profile compared to their linear analogs. Introduction of a handle in the para position of the P1 benzyl group proved difficult, despite efforts to synthesize intermediates containing either a bromo-, hydroxy-, methoxy-, silyl-group protected hydroxy- or an alkyne-group. The lactone intermediate was abandoned in favor of an alternative synthetic route and initial studies were found to be promising. This new approach requires further investigation before the target macrocycles can be synthesized.
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| 8. |
- Battisti, Umberto Maria, et al.
(författare)
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Ellagic Acid and Its Metabolites as Potent and Selective Allosteric Inhibitors of Liver Pyruvate Kinase
- 2023
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Ingår i: Nutrients. - : MDPI AG. - 2072-6643. ; 15:3
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Tidskriftsartikel (refereegranskat)abstract
- Liver pyruvate kinase (PKL) has recently emerged as a new target for non-alcoholic fatty liver disease (NAFLD), and inhibitors of this enzyme could represent a new therapeutic option. However, this breakthrough is complicated by selectivity issues since pyruvate kinase exists in four different isoforms. In this work, we report that ellagic acid (EA) and its derivatives, present in numerous fruits and vegetables, can inhibit PKL potently and selectively. Several polyphenolic analogues of EA were synthesized and tested to identify the chemical features responsible for the desired activity. Molecular modelling studies suggested that this inhibition is related to the stabilization of the PKL inactive state. This unique inhibition mechanism could potentially herald the development of new therapeutics for NAFLD.
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| 9. |
- Battisti, Umberto Maria, et al.
(författare)
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Exploration of Novel Urolithin C Derivatives as Non-Competitive Inhibitors of Liver Pyruvate Kinase
- 2023
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Ingår i: Pharmaceuticals. - : MDPI AG. - 1424-8247. ; 16:5
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Tidskriftsartikel (refereegranskat)abstract
- The inhibition of liver pyruvate kinase could be beneficial to halt or reverse non-alcoholic fatty liver disease (NAFLD), a progressive accumulation of fat in the liver that can lead eventually to cirrhosis. Recently, urolithin C has been reported as a new scaffold for the development of allosteric inhibitors of liver pyruvate kinase (PKL). In this work, a comprehensive structure-activity analysis of urolithin C was carried out. More than 50 analogues were synthesized and tested regarding the chemical features responsible for the desired activity. These data could pave the way to the development of more potent and selective PKL allosteric inhibitors.
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| 10. |
- Battisti, U. M., et al.
(författare)
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Serendipitous Identification of a Covalent Activator of Liver Pyruvate Kinase
- 2023
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Ingår i: ChemBioChem. - : Wiley. - 1439-4227 .- 1439-7633. ; 24:1
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Tidskriftsartikel (refereegranskat)abstract
- Enzymes are effective biological catalysts that accelerate almost all metabolic reactions in living organisms. Synthetic modulators of enzymes are useful tools for the study of enzymatic reactions and can provide starting points for the design of new drugs. Here, we report on the discovery of a class of biologically active compounds that covalently modifies lysine residues in human liver pyruvate kinase (PKL), leading to allosteric activation of the enzyme (EC50=0.29 μM). Surprisingly, the allosteric activation control point resides on the lysine residue K282 present in the catalytic site of PKL. These findings were confirmed by structural data, MS/MS experiments, and molecular modelling studies. Altogether, our study provides a molecular basis for the activation mechanism and establishes a framework for further development of human liver pyruvate kinase covalent activators.
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| 11. |
- Benitez-Martin, Carlos, 1994, et al.
(författare)
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Fluorescent Molecular Photoswitches for the Generation of All-Optical Encryption Keys
- 2023
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Ingår i: Chemphotochem. - 2367-0932.
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Tidskriftsartikel (refereegranskat)abstract
- Herein, we report a tri-component photochromic molecular cocktail that can be used to encrypt and decrypt information. The time-dependent fluorescent response of this cocktail is highly non-linear with respect to the set of inputs used (concentrations of the three photochromic components, excitation- and emission wavelengths), a property required for the generation of so-called encryption keys. The all-optical system can generate more than 80 million unique fluorescence responses by applying different input combinations and is operated using a conventional fluorimeter.
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| 12. |
- Bilsland, E., et al.
(författare)
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Plasmodium dihydrofolate reductase is a second enzyme target for the antimalarial action of triclosan
- 2018
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Malaria, caused by parasites of the genus Plasmodium, leads to over half a million deaths per year, 90% of which are caused by Plasmodium falciparum. P. vivax usually causes milder forms of malaria; however, P. vivax can remain dormant in the livers of infected patients for weeks or years before re-emerging in a new bout of the disease. The only drugs available that target all stages of the parasite can lead to severe side effects in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency; hence, there is an urgent need to develop new drugs active against blood and liver stages of the parasite. Different groups have demonstrated that triclosan, a common antibacterial agent, targets the Plasmodium liver enzyme enoyl reductase. Here, we provide 4 independent lines of evidence demonstrating that triclosan specifically targets both wild-type and pyrimethamine-resistant P. falciparum and P. vivax dihydrofolate reductases, classic targets for the blood stage of the parasite. This makes triclosan an exciting candidate for further development as a dual specificity antimalarial, which could target both liver and blood stages of the parasite.
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| 13. |
- Bliman, David, et al.
(författare)
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8-Bromination of 2,6,9-trisubstituted purines with pyridinium tribromide
- 2014
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Ingår i: Tetrahedron Letters. - : Elsevier Ltd. - 0040-4039 .- 1359-8562. ; 55:18, s. 2929-2931
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Tidskriftsartikel (refereegranskat)abstract
- 2,6,9-Trisubstituted purines are brominated in high yields using pyridinium tribromide as the brominating reagent. This procedure works excellently for electron-rich purines having electron-donating substituents at the 2- and 6-positions. The use of pyridinium tribromide, a crystalline alternative to elemental bromine, improves the bromination procedure for this type of substrate as the reagent is easy to handle and the work-up and purification procedures are simplified.
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| 14. |
- Bliman, David, et al.
(författare)
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A Caged Ret Kinase Inhibitor and its Effect on Motoneuron Development in Zebrafish Embryos
- 2015
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 5
-
Tidskriftsartikel (refereegranskat)abstract
- Proto-oncogene tyrosine-protein kinase receptor RET is implicated in the development and maintenance of neurons of the central and peripheral nervous systems. Attaching activity-compromising photocleavable groups (caging) to inhibitors could allow for external spatiotemporally controlled inhibition using light, potentially providing novel information on how these kinase receptors are involved in cellular processes. Here, caged RET inhibitors were obtained from 3-substituted pyrazolopyrimidine-based compounds by attaching photolabile groups to the exocyclic amino function. The most promising compound displayed excellent inhibitory effect in cell-free, as well as live-cell assays upon decaging. Furthermore, inhibition could be efficiently activated with light in vivo in zebrafish embryos and was shown to effect motoneuron development.
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| 15. |
- Blom, Magnus, 1984-
(författare)
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Light-Triggered Conformational Switches for Modulation of Molecular Recognition : Applications for Peptidomimetics and Supramolecular Systems
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The main focus of this thesis is on photochemical modulation of molecular recognition in various host-guest systems. This involves the design, synthesis and integration of light-triggered conformational switches into peptidomimetic guests and molecular tweezer hosts. The impact of the switches on guest and host structures has been assessed by spectroscopic and computational conformational analysis. Effects of photochemical structure modulation on molecular recognition in protein-ligand and supramolecular host-guest systems are discussed.Phototriggerable peptidomimetic inhibitors of the enzyme M. tuberculosis ribonucleotide reductase (RNR) were obtained by incorporation of a stilbene based amino acid moiety into oligopeptides between 3-9 residues long (Paper I). Interstrand hydrogen bond probability in the E and Z forms of the peptidomimetics was used as a tool for predicting conformational preferences. Considerable differences in inhibitory potency for the E and Z photoisomers were demonstrated in a binding assay.In order to advance the concept of photomodulable inhibitors, synthetic routes towards amino acid derivatives based on the more rigid stiff-stilbene chromophore were developed (Paper II). The effect of E-Z isomerization on the conformational properties of peptidomimetic inhibitors incorporating the stiff-stilbene chromophore was also assessed computationally (Paper III). It was indicated that inhibitors with the more rigid amino acid derivative should display larger conformational divergence between photoisomers than corresponding stilbene derivatives.Bisporphyrin tweezers with enediyne and stiff-stilbene spacers have been synthesized, and the conformational characteristics imposed by the spacers have been studied and compared to a glycoluril linked tweezer. The effects of spacers on tweezer binding of diamine guests and helicity induction by chiral guests have been investigated (Paper IV). Connections between spacer flexibility and host-guest binding strength have been established. The structural properties of the stiff-stilbene spaced tweezer made it particularly susceptible to helicity induction by both monotopic and bitopic chiral guests. Finally, the possibility of photochemical bite-size variation of tweezers with photoswitchable spacers has been assessed. Initial studies have shown that photoisomerization of the tweezers is possible without photochemical decomposition. Conformational analyses indicate that isomerization should impact binding characteristics of the tweezers to a significant extent (Paper V).
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| 16. |
- Bood, Mattias, et al.
(författare)
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Fluorescent nucleobase analogues for base-base FRET in nucleic acids: Synthesis, photophysics and applications
- 2018
-
Ingår i: Beilstein Journal of Organic Chemistry. - : Beilstein Institut. - 1860-5397. ; 14, s. 114-129
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Tidskriftsartikel (refereegranskat)abstract
- Forster resonance energy transfer (FRET) between a donor nucleobase analogue and an acceptor nucleobase analogue, base-base FRET, works as a spectroscopic ruler and protractor. With their firm stacking and ability to replace the natural nucleic acid bases inside the base-stack, base analogue donor and acceptor molecules complement external fluorophores like the Cy-, Alexa- and ATTO-dyes and enable detailed investigations of structure and dynamics of nucleic acid containing systems. The first base-base FRET pair, tCO-tCnitro, has recently been complemented with among others the adenine analogue FRET pair, qAN1-qAnitro, increasing the flexibility of the methodology. Here we present the design, synthesis, photophysical characterization and use of such base analogues. They enable a higher control of the FRET orientation factor, κ2, have a different distance window of opportunity than external fluorophores, and, thus, have the potential to facilitate better structure resolution. Netropsin DNA binding and the B-to-Z-DNA transition are examples of structure investigations that recently have been performed using base.base FRET and that are described here. Base-base FRET has been around for less than a decade, only in 2017 expanded beyond one FRET pair, and represents a highly promising structure and dynamics methodology for the field of nucleic acids. Here we bring up its advantages as well as disadvantages and touch upon potential future applications. © 2018 Bood et al.
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| 17. |
- Bood, Mattias, et al.
(författare)
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Interbase-FRET binding assay for pre-microRNAs
- 2021
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- The aberrant expression of microRNAs (miRs) has been linked to several human diseases. A promising approach for targeting these anomalies is the use of small-molecule inhibitors of miR biogenesis. These inhibitors have the potential to (i) dissect miR mechanisms of action, (ii) discover new drug targets, and (iii) function as new therapeutic agents. Here, we designed Forster resonance energy transfer (FRET)-labeled oligoribonucleotides of the precursor of the oncogenic miR-21 (pre-miR-21) and used them together with a set of aminoglycosides to develop an interbase-FRET assay to detect ligand binding to pre-miRs. Our interbase-FRET assay accurately reports structural changes of the RNA oligonucleotide induced by ligand binding. We demonstrate its application in a rapid, qualitative drug candidate screen by assessing the relative binding affinity between 12 aminoglycoside antibiotics and pre-miR-21. Surface plasmon resonance (SPR) and isothermal titration calorimetry (ITC) were used to validate our new FRET method, and the accuracy of our FRET assay was shown to be similar to the established techniques. With its advantages over SPR and ITC owing to its high sensitivity, small sample size, straightforward technique and the possibility for high-throughput expansion, we envision that our solution-based method can be applied in pre-miRNA-target binding studies.
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| 18. |
- Bood, Mattias, et al.
(författare)
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Pentacyclic adenine: a versatile and exceptionally bright fluorescent DNA base analogue
- 2018
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Ingår i: Chemical Science. - : Royal Society of Chemistry (RSC). - 2041-6520 .- 2041-6539. ; 9:14, s. 3494-3502
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Tidskriftsartikel (refereegranskat)abstract
- Emissive base analogs are powerful tools for probing nucleic acids at the molecular level. Herein we describe the development and thorough characterization of pentacyclic adenine (pA), a versatile base analog with exceptional fluorescence properties. When incorporated into DNA, pA pairs selectively with thymine without perturbing the B-form structure and is among the brightest nucleobase analogs reported so far. Together with the recently established base analog acceptor qAnitro, pA allows accurate distance and orientation determination via Forster resonance energy transfer (FRET) measurements. The high brightness at emission wavelengths above 400 nm also makes it suitable for fluorescence microscopy, as demonstrated by imaging of single liposomal constructs coated with cholesterolanchored pA-dsDNA, using total internal reflection fluorescence microscopy. Finally, pA is also highly promising for two-photon excitation at 780 nm, with a brightness (5.3 GM) that is unprecedented for a base analog.
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| 19. |
- Bourgard, Catarina, 1985, et al.
(författare)
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Development of Dicationic Bisguanidine-Arylfuran Derivatives as Potent Agents against Gram-Negative Bacteria.
- 2022
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Ingår i: Antibiotics. - : MDPI AG. - 2079-6382. ; 11:8
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Tidskriftsartikel (refereegranskat)abstract
- Antibiotic resistance among bacteria is a growing global challenge. A major reason for this is the limited progress in developing new classes of antibiotics active against Gram-negative bacteria. Here, we investigate the antibacterial activity of a dicationic bisguanidine-arylfuran, originally developed as an antitrypanosomal agent, and new derivatives thereof. The compounds showed good activity (EC50 2-20 µM) against antibiotic-resistant isolates of the Gram-negative members of the ESKAPE group (Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp.) and Escherichia coli with different antibiotic susceptibility patterns, including ESBL isolates. Cytotoxicity was moderate, and several of the new derivatives were less cytotoxic than the lead molecule, offering better selectivity indices (40-80 for several ESKAPE isolates). The molecular mechanism for the antibacterial activity of these molecules is unknown, but sensitivity profiling against human ESKAPE isolates and E. coli collections with known susceptibility patterns against established antibiotics indicates that it is distinct from lactam and quinolone antibiotics.
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| 20. |
- Brown, P. H., et al.
(författare)
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The biotin repressor: Modulation of allostery by corepressor analogs
- 2004
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Ingår i: Journal of Molecular Biology. - : Elsevier BV. - 0022-2836. ; 337:4, s. 857-869
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Tidskriftsartikel (refereegranskat)abstract
- The Escherichia coli biotin repressor functions in biotin retention and regulation of biotin biosynthesis. Biotin retention is accomplished via the two-step biotinylation of the biotin-dependent enzyme, acetyl-CoA carboxylase. In the first step of this reaction the substrates biotin and ATP are utilized in synthesis of the activated biotin, biotinyl-5'-AMP, while in the second step this activated biotin is transferred to a unique lysine residue of the biotin carboxyl carrier protein subunit of the carboxylase. Regulation of biotin biosynthesis is accomplished through binding of the repressor to the transcription control region of the biotin biosynthetic operon. The adenylated or activated biotin functions as the corepressor in this DNA binding process. The activated biotin is a mixed anhydride and thus labile. In efforts to develop tools for structural and thermodynamic studies of the biotin regulatory interactions, two analogs of the adenylate, a sulfamoyl derivative and an ester derivative, have been synthesized and functionally characterized. Results of fluorescence measurements indicate that both analogs bind with high affinity to the repressor and that both are inactive in biotin transfer to the acceptor protein. Functional studies of their corepressor properties indicate that while the sulfamoyl is a weak allosteric activator, the ester closely mimics the physiological corepressor in activation of assembly of the transcription repression complex. Results of these studies also provide further insight into the allosteric mechanism of the biotin repressor. (C) 2004 Elsevier Ltd. All rights reserved.
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| 21. |
- Carlsson, Anna-Carin, 1976, et al.
(författare)
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Microwave-assisted synthesis of the Schollkopf chiral auxiliaries: (3S)- and (3R)-3,6-dihydro-2,5-diethoxy-3-isopropyl-pyrazine
- 2006
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Ingår i: Tetrahedron Letters. - : Elsevier BV. - 0040-4039. ; 47:29, s. 5199-5201
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Tidskriftsartikel (refereegranskat)abstract
- A practical and efficient methodology for the laboratory scale preparation of Schollkopf's bis-lactim ether chiral auxiliaries (3S)- and (3R)-3,6-dihydro-2,5-diethoxy-3-isopropyl-pyrazine has been developed. The key step is the preparation of the 2,5diketopiperazine derivative by microwave-assisted heating in water. The protocol avoids reactions at low temperature and the use of high boiling solvents. Only inexpensive and readily available starting materials are required. The bis-lactim ethers were produced in high yields on a multigram scale. (c) 2006 Elsevier Ltd. All rights reserved.
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| 22. |
- Dahlén, Kristian, 1973, et al.
(författare)
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A scaffold approach to 3,6,8-trisubstituted flavones
- 2006
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Ingår i: Synlett. - : Georg Thieme Verlag KG. - 0936-5214 .- 1437-2096. ; :6, s. 897-900
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Tidskriftsartikel (refereegranskat)abstract
- An efficient synthetic approach to 3,6,8-trisubstituted flavone scaffolds has been developed based on Pd-mediated coupling reactions.
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| 23. |
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| 24. |
- Dahlén, Kristian, 1973, et al.
(författare)
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Synthesis of 2,3,6,8-tetrasubstituted chromone scaffolds.
- 2006
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Ingår i: The Journal of organic chemistry. - : American Chemical Society (ACS). - 0022-3263 .- 1520-6904. ; 71:18, s. 6863-6871
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Tidskriftsartikel (refereegranskat)abstract
- A useful and efficient synthetic strategy to 2,3,6,8-tetrasubstituted chromone derivatives has been developed. 2-Aryl/styryl-8-bromo-6-chloro-3-hydroxychromone derivatives were synthesized and used as scaffolds by introducing a variety of substituents in the 3-, 6-, and 8-positions using palladium-mediated reactions. Excellent regioselectivity in all positions could be obtained by performing reactions in the 8-position first, in which Stille, Heck, Suzuki, and Sonogashira reactions gave good to excellent yields of product (63-98%). Stille and Heck reactions in the 6-position also gave the desired products in good yields (64-86%). The hydroxy group in the 3-position was activated as a triflate and used in productive Stille reactions (63-94%). This hydroxyl group was also used in O-alkylation reactions with different functionalized alkyl bromides (57-88%). The flavonoids, which are based on the chromone structure, and other related ring systems, have several interesting biological activities. The chromones are also interesting structural scaffolds, and they have for example been designed to be used as mimetics of short peptides. The versatile applicability of chromone derivatives and especially their potential use in drug discovery implicates the importance of access to efficient synthetic routes to such compounds.
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| 25. |
- Danelius, Emma, et al.
(författare)
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Flexibility is important for inhibition of the MDM2/p53 protein-protein interaction by cyclic β-hairpins
- 2016
-
Ingår i: Organic and Biomolecular Chemistry. - : Royal Society of Chemistry (RSC). - 1477-0520 .- 1477-0539. ; 14, s. 10386-10393
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Tidskriftsartikel (refereegranskat)abstract
- © 2016 The Royal Society of Chemistry.Protein-protein interactions that have large, flat and featureless binding sites are difficult drug targets. In the development of their modulators conventional drug discovery strategies are often unsuccessful. Gaining a detailed understanding of the binding mode of protein-protein interaction inhibitors is therefore of vast importance for their future pharmaceutical use. The MDM2/p53 protein pair is a highly promising target for cancer treatment. Disruption of the protein complex using p53 α-helix mimetics has been shown to be a successful strategy to control p53 activity. To gain further insight into the binding of inhibitors to MDM2, the flexibility of four cyclic β-hairpins that act as α-helical mimetics and potential MDM2/p53 interaction inhibitors was investigated in relation to their inhibitory activity. MDM2-binding of the mimetics was determined using fluorescence polarization and surface plasmon resonance assays, whereas their conformation and dynamics in solution was described by the combined experimental and computational NAMFIS analysis. Molecular flexibility was shown to be important for the activity of the cyclic β-hairpin based MDM2 inhibitors.
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| 26. |
- Dierckx, Anke, 1986, et al.
(författare)
-
Characterization of photophysical and base-mimicking properties of a novel fluorescent adenine analogue in DNA
- 2011
-
Ingår i: Nucleic Acids Research. - : Oxford University Press (OUP). - 0305-1048 .- 1362-4962. ; 39:10, s. 4513-4524
-
Tidskriftsartikel (refereegranskat)abstract
- To increase the diversity of fluorescent base analogues with improved properties, we here present the straightforward click-chemistry-based synthesis of a novel fluorescent adenine-analogue triazole adenine (A(T)) and its photophysical characterization inside DNA. A(T) shows promising properties compared to the widely used adenine analogue 2-aminopurine. Quantum yields reach > 20% and > 5% in single- and double-stranded DNA, respectively, and show dependence on neighbouring bases. Moreover, A(T) shows only a minor destabilization of DNA duplexes, comparable to 2-aminopurine, and circular dichroism investigations suggest that A(T) only causes minimal structural perturbations to normal B-DNA. Furthermore, we find that A(T) shows favourable base-pairing properties with thymine and more surprisingly also with normal adenine. In conclusion, A(T) shows strong potential as a new fluorescent adenine analogue for monitoring changes within its microenvironment in DNA.
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| 27. |
- Dinér, Peter, 1976, et al.
(författare)
-
Design, synthesis, and characterization of a highly effective Hog1 inhibitor: a powerful tool for analyzing MAP kinase signaling in yeast.
- 2011
-
Ingår i: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 6:5
-
Tidskriftsartikel (refereegranskat)abstract
- The Saccharomyces cerevisiae High-Osmolarity Glycerol (HOG) pathway is a conserved mitogen-activated protein kinase (MAPK) signal transduction system that often serves as a model to analyze systems level properties of MAPK signaling. Hog1, the MAPK of the HOG-pathway, can be activated by various environmental cues and it controls transcription, translation, transport, and cell cycle adaptations in response to stress conditions. A powerful means to study signaling in living cells is to use kinase inhibitors; however, no inhibitor targeting wild-type Hog1 exists to date. Herein, we describe the design, synthesis, and biological application of small molecule inhibitors that are cell-permeable, fast-acting, and highly efficient against wild-type Hog1. These compounds are potent inhibitors of Hog1 kinase activity both in vitro and in vivo. Next, we use these novel inhibitors to pinpoint the time of Hog1 action during recovery from G(1) checkpoint arrest, providing further evidence for a specific role of Hog1 in regulating cell cycle resumption during arsenite stress. Hence, we describe a novel tool for chemical genetic analysis of MAPK signaling and provide novel insights into Hog1 action.
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| 28. |
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| 29. |
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| 30. |
- Dinér, Peter, 1976, et al.
(författare)
-
Preparation of 3-Substituted-1-Isopropyl-1H-pyrazolo 3,4-d pyrimidin-4-amines as RET Kinase Inhibitors
- 2012
-
Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society (ACS). - 0022-2623 .- 1520-4804. ; 55:10, s. 4872-4876
-
Tidskriftsartikel (refereegranskat)abstract
- A series of 3-substituted-1-isopropyl-1H-pyrazolo[3,4-d]pyrimidin-4-amines have been designed, synthesized, and evaluated as RET protein kinase inhibitors. On the basis of docking results, a small library of pyrazolopyrimidine compounds with an extended hydrophobic side arm was synthesized. The most promising of the compounds (7a) displayed efficient inhibition in vitro and good selectivity when tested on a panel of kinases. Furthermore, 7a inhibited GDNF-induced RET phosphorylation of ERK1/2 in MCF-7 breast cancer cells at concentrations as low as 100 nM.
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| 31. |
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| 32. |
- Dinér, Peter, 1976, et al.
(författare)
-
Short cut to 1,2,3-triazole-based p38 MAP kinase inhibitors via [3+2]-cycloaddition chemistry
- 2009
-
Ingår i: New J. Chem.. - : Royal Society of Chemistry (RSC). - 1144-0546 .- 1369-9261. ; 33:5, s. 1010-1016
-
Tidskriftsartikel (refereegranskat)abstract
- A series of 4,5-substituted 1,2,3-triazoles was synthesised via Cu(I)-catalysed azide–alkyne 1,3-dipolar [2+3]-cycloaddition reactions followed by a Suzuki coupling. The 1,2,3-triazoles were evaluated as inhibitors of the p38 MAP kinase, showing IC50 values in the high nanomolar range
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| 33. |
- Dumat, Blaise, 1984, et al.
(författare)
-
Second-Generation Fluorescent Quadracyclic Adenine Analogues: Environment-Responsive Probes with Enhanced Brightness
- 2015
-
Ingår i: Chemistry - A European Journal. - : Wiley. - 0947-6539 .- 1521-3765. ; 21:10, s. 4039-4048
-
Tidskriftsartikel (refereegranskat)abstract
- Fluorescent base analogues comprise a group of increasingly important molecules for the investigation of nucleic acid structure, dynamics, and interactions with other molecules. Herein, we report on the quantum chemical calculation aided design, synthesis, and characterization of four new putative quadracyclic adenine analogues. The compounds were efficiently synthesized from a common intermediate through a two-step pathway with the Suzuki-Miyaura coupling as the key step. Two of the compounds, qAN1 and qAN4, display brightnesses (εΦF) of 1700 and 2300, respectively, in water and behave as wavelength-ratiometric pH probes under acidic conditions. The other two, qAN2 and qAN3, display lower brightnesses but exhibit polarity-sensitive dual-band emissions that could prove useful to investigate DNA structural changes induced by DNA-protein or -drug interactions. The four qANs are very promising microenvironment-sensitive fluorescent adenine analogues that display considerable brightness for such compounds. Polarity and pH probes: 2-Aminopurine has long been the standard for fluorescent base analogues. Four new fluorescent probes suitable for the replacement of adenine in nucleic acids are presented. Based on their high structural similarity to their parent compound, quadracyclic adenine, they have the potential to be excellent A analogues. Their improved photophysical properties also suggest that they could be significantly brighter than 2-aminopurine inside nucleic acid systems (see figure; ΦF: fluorescence quantum yield).
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| 34. |
- Dyrager, Christine, 1975, et al.
(författare)
-
2,6,8-Trisubstituted 3-hydroxychromone derivatives as fluorophores for live-cell imaging.
- 2009
-
Ingår i: Chemistry (Weinheim an der Bergstrasse, Germany). - : Wiley. - 1521-3765 .- 0947-6539. ; 15:37, s. 9417-23
-
Tidskriftsartikel (refereegranskat)abstract
- We present the synthesis and photophysical characterisation of a series of structurally diverse, fluorescent 2,6,8-trisubstituted 3-hydroxychromone derivatives with high fluorescence quantum yields and molar extinction coefficients. Two of these derivatives (9 and 10 a) have been studied as fluorophores for cellular imaging in HeLa cells and show excellent permeability and promising fluorescence properties in a cellular environment. In addition, we have demonstrated by photophysical characterisation of 3-isobutyroxychromone derivatives that esterification of the 3-hydroxyl group results in acceptable and useful fluorescence properties.
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| 35. |
- Dyrager, Christine, 1975, et al.
(författare)
-
Design, synthesis, and biological evaluation of chromone-based p38 MAP kinase inhibitors
- 2011
-
Ingår i: Journal of Medicinal Chemistry. ; 54, s. 7427-7431
-
Tidskriftsartikel (refereegranskat)abstract
- 3-(4-Fluorophenyl)-2-(4-pyridyl)chromone derivatives were synthesized and evaluated as p38 MAP kinase inhibitors. Introduction of an amino group in the 2-position of the pyridyl moiety gave p38α inhibitors with IC(50) in the low nanomolar range (e.g., IC(50) = 17 nm). The inhibitors showed excellent selectivity profiles when tested on a panel of 62 kinases, as well as efficient inhibition of p38 signaling in human breast cancer cells.
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| 36. |
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| 37. |
- Dyrager, Christine, et al.
(författare)
-
Design, Synthesis and Biological Evaluation of Chromone-based p38 MAP Kinase Inhibitors
- 2011
-
Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society (ACS). - 0022-2623 .- 1520-4804. ; 54:20, s. 7427-7431
-
Tidskriftsartikel (refereegranskat)abstract
- A series of 3-(4-fluorophenyl)-2-(4-pyridyl)-chromone derivs. were synthesized and evaluated as p38 MAP kinase inhibitors. Introduction of an amino group in the 2-position of the pyridyl moiety gave p38 inhibitors with IC50 values in the low nanomolar range (e.g. 8a; IC50 = 17 nm). Addnl., the inhibitors (8a and 8e) demonstrate an excellent selectivity profile towards the p38 kinase among other kinases, as well as inhibition (8e) of p38 signaling in human breast cancer cells. [on SciFinder(R)]
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| 38. |
- Dyrager, Christine, 1975, et al.
(författare)
-
Inhibitors and promoters of tubulin polymerization : Synthesis and biological evaluation of chalcones and related dienones as potential anticancer agents
- 2011
-
Ingår i: Bioorganic & Medicinal Chemistry. - : Elsevier BV. - 0968-0896 .- 1464-3391. ; 19:8, s. 2659-2665
-
Tidskriftsartikel (refereegranskat)abstract
- A series of dihalogenated chalcones and structurally related dienones were synthesized and evaluated for their antiproliferative activity in 10 different cancer cell lines and for their effect on microtubule assembly. All compounds showed cytotoxic activity, with IC50 values in the 5-280 mu M range depending on the chalcone structure and the cell line. Five of the compounds were found to be tubulin polymerization inhibitors. In contrast, one of the compounds was found to stabilize tubulin to the same extent as the anticancer drug docetaxel. Molecular modeling suggested that the tubulin inhibitors bind to the colchicine binding site of beta-tubulin while the novel tubulin stabilization agent seems to interact with the paclitaxel binding site.
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| 39. |
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| 40. |
- Falenczyk, C., et al.
(författare)
-
Chromo-pharmacophores: Photochromic diarylmaleimide inhibitors for sirtuins
- 2014
-
Ingår i: Chemical Science. - : Royal Society of Chemistry (RSC). - 2041-6520 .- 2041-6539. ; 5:12, s. 4794-4799
-
Tidskriftsartikel (refereegranskat)abstract
- © the Partner Organisations 2014. Controlling the activity of sirtuins is of high biomedical relevance as the enzymes are involved in cancer, neurodegeneration and other diseases. Therefore structural elements of 3,4-bisindoylmaleimides (BIMs), which are known NAD+-dependent histone deacetylase (sirtuin) inhibitors, were merged with photochromic diarylmaleimides to yield photoswitchable enzyme inhibitors. The new inhibitors show excellent photophysical properties, are switchable even in polar solvents, and subtype selective against hSirt2. The inhibitory activity changes up to a factor of 22 for the two photoisomers and physiological properties can therefore be effectively toggled by irradiation with light of different wavelengths. Docking experiments using the enzyme crystal structure explain the observed activity changes based on the steric demand of the thiophene substitution and the rigidity of the molecular structure. This journal is
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| 41. |
- Ferreira, Ruben, 1982, et al.
(författare)
-
Design, Synthesis and Inhibitory Activity of Photoswitchable RET Kinase Inhibitors.
- 2015
-
Ingår i: Scientific reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 5
-
Tidskriftsartikel (refereegranskat)abstract
- REarranged during Transfection (RET) is a transmembrane receptor tyrosine kinase required for normal development and maintenance of neurons of the central and peripheral nervous systems. Deregulation of RET and hyperactivity of the RET kinase is intimately connected to several types of human cancers, most notably thyroid cancers, making it an attractive therapeutic target for small-molecule kinase inhibitors. Novel approaches, allowing external control of the activity of RET, would be key additions to the signal transduction toolbox. In this work, photoswitchable RET kinase inhibitors based on azo-functionalized pyrazolopyrimidines were developed, enabling photonic control of RET activity. The most promising compound displays excellent switching properties and stability with good inhibitory effect towards RET in cell-free as well as live-cell assays and a significant difference in inhibitory activity between its two photoisomeric forms. As the first reported photoswitchable small-molecule kinase inhibitor, we consider the herein presented effector to be a significant step forward in the development of tools for kinase signal transduction studies with spatiotemporal control over inhibitor concentration in situ.
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| 42. |
- Ferreira, Raphael, 1990, et al.
(författare)
-
Photoswitch kinase inhibitors
- 2014
-
Ingår i: Purinergic Signalling. - 1573-9538 .- 1573-9546. ; 10:4, s. 767-768
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 43. |
- Fisher, Rachel S., et al.
(författare)
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Pulse-shaped two-photon excitation of a fluorescent base analogue approaches single-molecule sensitivity
- 2018
-
Ingår i: Physical Chemistry Chemical Physics. - : Royal Society of Chemistry (RSC). - 1463-9084 .- 1463-9076. ; 20:45, s. 28487-28498
-
Tidskriftsartikel (refereegranskat)abstract
- Fluorescent nucleobase analogues (FBAs) have many desirable features in comparison to extrinsic fluorescent labels, but they are yet to find application in ultrasensitive detection. Many of the disadvantages of FBAs arise from their short excitation wavelengths (often in the ultraviolet), making two-photon excitation a potentially attractive approach. Pentacyclic adenine (pA) is a recently developed FBA that has an exceptionally high two-photon brightness. We have studied the two-photon-excited fluorescence properties of pA and how they are affected by incorporation in DNA. We find that pA is more photostable under two-photon excitation than via resonant absorption. When incorporated in an oligonucleotide, pA has a high two-photon cross section and emission quantum yield, varying with sequence context, resulting in the highest reported brightness for such a probe. The use of a two-photon microscope with ultrafast excitation and pulse shaping has allowed the detection of pA-containing oligonucleotides in solution with a limit of detection of ∼5 molecules, demonstrating that practical single-molecule detection of FBAs is now within reach.
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| 44. |
- Fleming, Cassandra, 1987, et al.
(författare)
-
A Fluorescent Kinase Inhibitor that Exhibits Diagnostic Changes in Emission upon Binding
- 2019
-
Ingår i: Angewandte Chemie - International Edition. - : Wiley. - 1433-7851 .- 1521-3773. ; 58:42, s. 15000-15004
-
Tidskriftsartikel (refereegranskat)abstract
- The development of a fluorescent LCK inhibitor that exhibits favourable solvatochromic properties upon binding the kinase is described. Fluorescent properties were realised through the inclusion of a prodan-derived fluorophore into the pharmacophore of an ATP-competitive kinase inhibitor. Fluorescence titration experiments demonstrate the solvatochromic properties of the inhibitor, in which dramatic increase in emission intensity and hypsochromic shift in emission maxima are clearly observed upon binding LCK. Microscopy experiments in cellular contexts together with flow cytometry show that the fluorescence intensity of the inhibitor correlates with the LCK concentration. Furthermore, multiphoton microscopy experiments demonstrate both the rapid cellular uptake of the inhibitor and that the two-photon cross section of the inhibitor is amenable for excitation at 700 nm.
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| 45. |
- Fleming, Cassandra L., et al.
(författare)
-
All-photonic kinase inhibitors: light-controlled release-and-report inhibition
- 2024
-
Ingår i: CHEMICAL SCIENCE. - 2041-6520 .- 2041-6539. ; 15:18, s. 6897-6905
-
Tidskriftsartikel (refereegranskat)abstract
- Light-responsive molecular tools targeting kinases affords one the opportunity to study the underlying cellular function of selected kinases. In efforts to externally control lymphocyte-specific protein tyrosine kinase (LCK) activity, the development of release-and-report LCK inhibitors is described, in which (i) the release of the active kinase inhibitor can be controlled externally with light; and (ii) fluorescence is employed to report both the release and binding of the active kinase inhibitor. This introduces an unprecedented all-photonic method for users to both control and monitor real-time inhibitory activity. A functional cellular assay demonstrated light-mediated LCK inhibition in natural killer cells. The use of coumarin-derived caging groups resulted in rapid cellular uptake and non-specific intracellular localisation, while a BODIPY-derived caging group predominately localised in the cellular membrane. This concept of release-and-report inhibitors has the potential to be extended to other biorelevant targets where both spatiotemporal control in a cellular setting and a reporting mechanism would be beneficial. An all-photonic method is described, in which (i) the release of an active kinase inhibitor is controlled externally with light; and (ii) fluorescence is employed to report both the release and binding of the inhibitor to its corresponding target.
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| 46. |
- Fleming, Cassandra L., et al.
(författare)
-
On-Command Regulation of Kinase Activity using Photonic Stimuli
- 2019
-
Ingår i: ChemPhotoChem. - : Wiley. - 2367-0932. ; 3:6, s. 318-326
-
Forskningsöversikt (refereegranskat)abstract
- The underlying role that many kinases play in complex cellular pathways as well as disease remains unclear. To better understand the role that kinases play in both health and disease states, the use of light as an external stimulus to modulate kinase activity with high spatiotemporal resolution has gained increasing interest over the years. Herein we highlight the progress made towards the development of light-responsive kinase enzymes and small molecule inhibitors. In these examples, photolabile caging groups and photoswitchable entities have been utilised to modulate either kinase activation or inhibition in a light-controlled manner.
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| 47. |
- Fleming, Cassandra L., et al.
(författare)
-
Shining New Light on the Spiropyran Photoswitch: A Photocage Decides between cis-trans or Spiro-Merocyanine Isomerization
- 2018
-
Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 140:43, s. 14069-14072
-
Tidskriftsartikel (refereegranskat)abstract
- Photochromic molecules from the spiropyran family are known to undergo light-induced interconversion between the colorless spiro- and the colored merocyanine forms. Here, we show for the first time that small structural modifications open up for an additional photoisomerization mode: reversible cis-trans isomerization of the merocyanine. Moreover, the introduction of a photocage allows for light-activated switching between the two modes.
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| 48. |
- Fleming, Cassandra, 1987, et al.
(författare)
-
On the use of diarylmaleimide derivatives in biological contexts: An investigation of the photochromic properties in aqueous solution
- 2017
-
Ingår i: Dyes and Pigments. - : Elsevier BV. - 0143-7208 .- 1873-3743. ; 137, s. 410-420
-
Tidskriftsartikel (refereegranskat)abstract
- A series of photochromic diarylmaleimide derivatives has been synthesized and studied with respect to the photochromic properties in aqueous solution. The main rationale is to investigate if these compounds could be used as photoswitchable units in biological contexts, motivated by the fact that the diarylmaleimide structural motif is identified in many pharmacophores. Thus, photoswitchable variants of this class of compounds could be very useful in the quest for photoactivatable drugs. The photoinduced cyclization reaction (colorization) is suppressed in solvents of high polarity, whereas the ring-opening reaction (decolorization) still occurs with high efficiency. The photochromically active anti-parallel conformer of the open form is more abundant in the asymmetrically substituted derivatives, which in turn favors the formation of the closed isomeric form. The rates of the thermal isomerization reactions have also been assessed, together with the resistance toward thermal degradation. Here it was observed that the maleimide derived compounds were not susceptible to the thermally driven reactions (hydrolysis and isomerization). (C) 2016 Elsevier Ltd. All rights reserved.
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| 49. |
- Fridén-Saxin, Maria, 1979, et al.
(författare)
-
Chroman-4-one and chromone based somatostatin beta-turn mimetics
- 2016
-
Ingår i: European Journal of Medicinal Chemistry. - : Elsevier BV. - 0223-5234. ; 114, s. 59-64
-
Tidskriftsartikel (refereegranskat)abstract
- A scaffold approach has been used to develop somatostatin beta-turn mimetics based on chroman-4-one and chromone ring systems. Such derivatives could adopt conformations resembling type II or type II' beta-turns. Side chain equivalents of the crucial Trp8 and Lys9 in somatostatin were introduced in the 2- and 8-positions of the scaffolds using efficient reactions. Interestingly, this proof-of-concept study shows that 4 and 9 have K-i-values in the low mu M range when evaluated for their affinity for the sst2 and sst4 receptors. (C) 2016 Elsevier Masson SAS. All rights reserved.
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| 50. |
- Fridén-Saxin, Maria, 1979, et al.
(författare)
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Proline-mediated formation of novel chroman-4-one tetrahydropyrimidines
- 2012
-
Ingår i: Tetrahedron. - : Elsevier BV. - 0040-4020. ; 68:35, s. 7035-7040
-
Tidskriftsartikel (refereegranskat)abstract
- Novel tricyclic N-benzylated chroman-4-one tetrahydropyrimidine derivatives have been prepared through a multi-component reaction between various 2-substituted chroman-4-one derivatives, N-methylenebenzylamine and a catalytic amount of proline under mild reaction conditions. The tricyclic structure of 1a was determined by NMR spectroscopy and confirmed by X-ray crystallography. An additional product, 2a, was isolated from the reaction mixture and its structure and conformation were determined by a combination of theoretical (Monte Carlo conformational search) and NMR-based (NOE and (3)J(HH) couplings) conformational analysis. The NMR analysis revealed one preferred geometry for 1a and 2a in CHCl3 solution. (C) 2012 Elsevier Ltd. All rights reserved.
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