Publications (10)34.81 Total impact
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Article: Imidazonaphthyridine systems (part 2): Functionalization of the phenyl ring linked to the pyridine pharmacophore and its replacement by a pyridinone ring produces intriguing differences in cytocidal activity.
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ABSTRACT: We recently discovered that five- and pseudo-five-fused-ring derivatives in an imidazonaphthyridine series were promising hit compounds for the development of new DNA-intercalators. In this study, novel (dihydro)imidazo[1,6] and [1,7]naphthyridi(no)nes were prepared including pseudo-pentacycles. All the compounds synthesized were screened against four tumor cell lines. Compounds 3(b-d) showed significant in vitro cytotoxicity, and DNA intercalation properties were demonstrated at 25 μM. Imidazonaphthyridinones exhibited no DNA binding affinity despite significant growth inhibition activity. Interestingly, when a pyridinone pharmacophore was linked to the imidazo[1,2-a]pyridine scaffold, the geometric orientation of the link had a strong impact on the growth inhibition activity. From these results we conclude that the moderate cytotoxicity observed for these compounds is independent of their DNA-binding and topoisomerase inhibition activities.European journal of medicinal chemistry 03/2012; 52:137-50. · 3.27 Impact Factor -
Article: Systematic synthesis of inhibitors of the two first enzymes of the bacterial heptose biosynthetic pathway: towards antivirulence molecules targeting lipopolysaccharide biosynthesis.
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ABSTRACT: L-Heptoses (L-glycero-D-manno-heptopyranoses) are constituents of the inner core of lipolysaccharide (LPS), a molecule playing key roles in the mortality of many infectious diseases as well as in the virulence of many human pathogens. The inhibition of the first enzymes of the bacterial heptose biosynthetic pathway is an almost unexplored field to date although it appears to be a very novel way for the development of antivirulence drugs. We report the synthesis of a series of D-glycero-D-manno-heptopyranose 7-phosphate (H7P) analogues and their inhibition properties against the isomerase GmhA and the the kinase HldE, the two first enzymes of the bacterial heptose biosynthetic pathway. The heptose structures have been modified at the 1-, 2-, 6- and 7-positions to probe the importance of the key structural features of H7P that allow a tight binding to the target enzymes; H7P being the product of GmhA and the substrate of HldE, the second objective was to find structures that could simultaneously inhibit both enzymes. We found that GmhA and HldE were extremely sensitive to structural modifications at the 6- and 7- positions of the heptose scaffold. To our surprise, the epimeric analogue of H7P displaying a D-glucopyranose configuration was found to be the best inhibitor of both enzymes but also the only molecule of this series that could inhibit GmhA (IC(50)=34 μM) and HldE (IC(50)=9.4 μM) in the low micromolar range. Noteworthy, this study describes the first inhibitors of GmhA ever reported, and paves the way to the design of a second generation of molecules targeting the bacterial virulence.Chemistry 09/2011; 17(40):11305-13. · 5.93 Impact Factor -
Article: Synthesis of functionalized cinnamaldehyde derivatives by an oxidative Heck reaction and their use as starting materials for preparation of Mycobacterium tuberculosis 1-deoxy-D-xylulose-5-phosphate reductoisomerase inhibitors.
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ABSTRACT: Cinnamaldehyde derivatives were synthesized in good to excellent yields in one step by a mild and selective, base-free palladium(II)-catalyzed oxidative Heck reaction starting from acrolein and various arylboronic acids. Prepared α,β-unsaturated aldehydes were used for synthesis of novel α-aryl substituted fosmidomycin analogues, which were evaluated for their inhibition of Mycobacterium tuberculosis 1-deoxy-D-xylulose 5-phosphate reductoisomerase. IC(50) values between 0.8 and 27.3 μM were measured. The best compound showed activity comparable to that of the most potent previously reported α-aryl substituted fosmidomycin-class inhibitor.The Journal of Organic Chemistry 09/2011; 76(21):8986-98. · 4.45 Impact Factor -
Article: Substitution of the phosphonic acid and hydroxamic acid functionalities of the DXR inhibitor FR900098: an attempt to improve the activity against Mycobacterium tuberculosis.
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ABSTRACT: Two series of FR900098/fosmidomycin analogs were synthesized and evaluated for MtDXR inhibition and Mycobacterium tuberculosis whole-cell activity. The design rationale of these compounds involved the exchange of either the phosphonic acid or the hydroxamic acid part for alternative acidic and metal-coordinating functionalities. The best inhibitors provided IC(50) values in the micromolar range, with a best value of 41 μM.Bioorganic & medicinal chemistry letters 09/2011; 21(18):5403-7. · 2.65 Impact Factor -
Article: Design, synthesis, and X-ray crystallographic studies of α-aryl substituted fosmidomycin analogues as inhibitors of Mycobacterium tuberculosis 1-deoxy-D-xylulose 5-phosphate reductoisomerase.
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ABSTRACT: The natural antibiotic fosmidomycin acts via inhibition of 1-deoxy-d-xylulose 5-phosphate reductoisomerase (DXR), an essential enzyme in the non-mevalonate pathway of isoprenoid biosynthesis. Fosmidomycin is active on Mycobacterium tuberculosis DXR (MtDXR), but it lacks antibacterial activity probably because of poor uptake. α-Aryl substituted fosmidomycin analogues have more favorable physicochemical properties and are also more active in inhibiting malaria parasite growth. We have solved crystal structures of MtDXR in complex with 3,4-dichlorophenyl substituted fosmidomycin analogues; these show important differences compared to our previously described forsmidomycin-DXR complex. Our best inhibitor has an IC(50) = 0.15 μM on MtDXR but still lacked activity in a mycobacterial growth assay (MIC > 32 μg/mL). The combined results, however, provide insights into how DXR accommodates the new inhibitors and serve as an excellent starting point for the design of other novel and more potent inhibitors, particularly against pathogens where uptake is less of a problem, such as the malaria parasite.Journal of Medicinal Chemistry 06/2011; 54(14):4964-76. · 4.80 Impact Factor -
Article: Microwave-promoted palladium(II)-catalyzed C-P bond formation by using arylboronic acids or aryltrifluoroborates.
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ABSTRACT: The first Pd(II)-catalyzed P arylation has been performed by using palladium acetate, the rigid bidentate ligand dmphen (dmphen=2,9-dimethyl-1,10-phenanthroline), and without the addition of base or acid. Couplings of arylboronic acids or aryl trifluoroborates with H-phosphonate dialkyl esters were conducted in 30 min with controlled microwave (MW) heating under non-inert conditions. Aryl phosphites were also synthesized at room temperature with atmospheric air as the sole reoxidant. The arylated phosphonates were isolated in 44-90 % yields. The excellent chemoselectivity of the method was illustrated in the synthesis of a Mycobacterium tuberculosis glutamine synthetase (MTB-GS) inhibitor. Online ESIMS was used to detect cationic palladium species in ongoing reactions directly, and a catalytic cycle has been proposed based on these results.Chemistry 10/2009; 15(47):13069-74. · 5.93 Impact Factor -
Article: Fine tuning of electrostatics around the internucleotidic phosphate through incorporation of modified 2',4'-carbocyclic-LNAs and -ENAs leads to significant modulation of antisense properties.
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ABSTRACT: In the antisense (AS) and RNA interference (RNAi) technologies, the native single-stranded 2'-deoxyoligonucleotides (for AS) or double-stranded RNA (for RNAi) are chemically modified to bind to the target RNA in order to give improved downregulation of gene expression through inhibition of RNA translation. It is shown here how the fine adjustment of the electrostatic interaction by alteration of the substituents as well as their stereochemical environment around the internucleotidic phosphodiester moiety near the edge of the minor grove of the antisense oligonucleotides (AON)-RNA heteroduplex can lead to the modulation of the antisense properties. This was demonstrated through the synthesis of various modified carbocyclic-locked nucleic acids (LNAs) and -ethylene-bridged nucleic acids (ENAs) with hydroxyl and/or methyl substituents attached at the carbocyclic part and their integration into AONs by solid-phase DNA synthesis. The target affinity toward the complementary RNA and DNA, nuclease resistance, and RNase H elicitation by these modified AONs showed that both the nature of the modification (-OH versus -CH(3)) and their respective stereochemical orientations vis-a-vis vicinal phosphate play a very important role in modulating the AON properties. Whereas the affinity to the target RNA and the enzymatic stability of AONs were not favored by the hydrophobic and sterically bulky modifications in the center of the minor groove, their positioning at the edge of the minor groove near the phosphate linkage resulted in significantly improved nuclease resistance without loss of target affinity. On the other hand, hydrophilic modification, such as a hydroxyl group, close to the phosphate linkage made the internucleotidic phosphodiester especially nucleolytically unstable, and hence was not recommended. The substitutions on the carbocyclic moiety of the carba-LNA and -ENA did not affect significantly the choice of the cleavage sites of RNase H mediated RNA cleavage in the AON/RNA hybrid duplex, but the cleavage rate depended on the modification site in the AON sequence. If the original preferred cleavage site by RNase H was included in the 4-5nt stretch from the 3'-end of the modification site in the AON, decreased cleavage rate was observed. Upon screening of 52 modified AONs, containing 13 differently modified derivatives at C6' and C7' (or C8') of the carba-LNAs and -ENAs, two excellent modifications in the carba-LNA series were identified, which synergistically gave outstanding antisense properties such as the target RNA affinity, nuclease resistance, and RNase H activity and were deemed to be ideal candidates as potential antisense or siRNA therapeutic agents.The Journal of Organic Chemistry 01/2009; 74(1):118-34. · 4.45 Impact Factor -
Article: Novel imidazo[1,2-a]naphthyridinic systems (part 1): synthesis, antiproliferative and DNA-intercalating activities.
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ABSTRACT: Novel imidazo[1,2-a]naphthyridinic systems 6a-15a and 6b-15b were obtained from Friedländer's reaction in imidazo[1,2-a]pyridine series. Most of the compounds were evaluated for their antitumor activity in the NCIs in vitro human tumor cell line screening panel. Among them, pentacyclic derivatives 13b and 14a exhibited in vitro activity comparable to anticancer agent such as amsacrine. Their mechanism of cytotoxicity action was unrelated to poisoning or inhibiting abilities against topo1. On the contrary, we highlighted a direct intercalation of the drugs into DNA by electrophoresis on agarose gel.European Journal of Medicinal Chemistry 03/2008; 43(11):2505-17. · 3.35 Impact Factor -
Article: A convenient synthesis of linear pyridinoimidazo[1,2-a]pyridine and pyrroloimidazo[1,2-a]pyridine cores
Tetrahedron Letters. 48(47):8392-8395. -
Article: Preliminary Study of Palladium Catalyzed Iminoannulation in an Imidazo[1,2-a]pyridine Series
Heterocycles. 65(5):1071-1078.
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Institutions
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2011
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Uppsala University
- Department of Medicinal Chemistry
Uppsala, Uppsala, Sweden
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