| 1. |
- Almqvist, Fredrik, et al.
(författare)
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Spirobicyclo[2.2.2]octane derivatives: mimetics of baccatin III and paclitaxel (Taxol)
- 2004
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Ingår i: Organic and Biomolecular Chemistry. - 1477-0539. ; 2:21, s. 3085-3090
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Tidskriftsartikel (refereegranskat)abstract
- The formylated spirobyclic alcohol 8a was computer modeled to be a mimetic of paclitaxel. In this model, the formyl group was used as a truncated paclitaxel side chain in order to reduce the computational work. Compound 8c, carrying the paclitaxel side chain, was synthesized in six steps from optically active 1,3-diketone 12. Microtubule stabilization was not observed for 8c, indicating that the model needs to be adjusted.
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| 2. |
- Almqvist, Fredrik, et al.
(författare)
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Spirobicyclo[2.2.2]octane derivatives: mimetics of baccatin III and paclitaxel (Taxol)
- 2004
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Ingår i: ORGANIC & BIOMOLECULAR CHEMISTRY. - : Royal Society of Chemistry (RSC). - 1477-0520 .- 1477-0539. ; 2:21, s. 3085-90
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Tidskriftsartikel (refereegranskat)abstract
- The formylated spirobyclic alcohol 8a was computer modeled to be a mimetic of paclitaxel. In this model, the formyl group was used as a truncated paclitaxel side chain in order to reduce the computational work. Compound 8c, carrying the paclitaxel side chain, was synthesized in six steps from optically active 1,3-diketone 12. Microtubule stabilization was not observed for 8c, indicating that the model needs to be adjusted.
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| 3. |
- Aplander, Karolina, et al.
(författare)
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Molecular wipes : application to epidemic keratoconjuctivitis
- 2011
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Ingår i: Journal of Medicinal Chemistry. - Easton, Pa. : American Chemical Society. - 0022-2623 .- 1520-4804. ; 54:19, s. 6670-6675
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Tidskriftsartikel (refereegranskat)abstract
- Epidemic keratoconjunctivitis (EKC) is a severe disease of the eye, caused by members of the Adenoviridae (Ad) family, with symptoms such as keratitis, conjunctivitis, pain, edema, and reduced vision that may last for months or years. There are no vaccines or antiviral drugs available to prevent or treat EKC. It was found previously that EKC-causing Ads use sialic acid as a cellular receptor and demonstrated that soluble, sialic acid-containing molecules can prevent infection. In this study, multivalent sialic acid constructs based on 10,12-pentacosadiynoic acid (PDA) have been synthesized, and these constructs are shown to be efficient inhibitors of Ad binding (IC(50) = 0.9 mu M) and Ad infectivity (IC(50) = 0.7 mu M). The mechanism of action is to aggregate virus particles and thereby prevent them from binding to ocular cells. Such formulations may be used for topical treatment of adenovirus-caused EKC.
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| 4. |
- Ek, Fredrik, et al.
(författare)
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Synthesis of fused tetrazole derivatives via a tandem cycloaddition and N-allylation reaction and parallel synthesis of fused tetrazole amines
- 2004
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Ingår i: Journal of Organic Chemistry. - : American Chemical Society (ACS). - 1520-6904 .- 0022-3263. ; 69:4, s. 1346-1352
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Tidskriftsartikel (refereegranskat)abstract
- A method for the synthesis of novel fused tricyclic tetrazoles from allylic bromides generated by the recently discovered DiazAll reaction has been developed. This new tandem reaction comprises a cycloaddition between a nitrile and (TMS)N-3 followed by an intramolecular N-allylation. The variation of functionalities in the benzene moiety was well-tolerated, and only a moderate difference in yield and degree of purity was noticed. An exo-methylene group in these new compounds permitted further derivatization. Structural resemblance with substances which possess important pharmacological properties motivated the synthesis of a series of ketones and a small library of amines.
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| 5. |
- Gonzales-Ramirez, Mariela, et al.
(författare)
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Trichilones A–E: New Limonoids from Trichilia adolfi
- 2021
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Ingår i: Molecules. - : MDPI AG. - 1420-3049. ; 26:11
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Tidskriftsartikel (refereegranskat)abstract
- In addition to the trichilianones A–D recently reported from Trichilia adolfi, a continuing investigation of the chemical constituents of the ethanol extract of the bark of this medicinal plant yielded the five new limonoids 1–5. They are characterized by having four fused rings and are new examples of prieurianin-type limonoids, having a ε-lactone which in 4 and 5 is α, β- unsaturated. The structures of the isolated metabolites were determined by high field NMR spectroscopy and HR mass spectrometry. The new metabolites were shown to have the ε-lactone fused with a tetrahydrofuran ring which is connected to an oxidized hexane ring joined with a cyclo-pentanone having a 3-furanyl substituent. As the crude extract possesses antileishmanial activity, the compounds were assayed for cytotoxic and antiparasitic activities in vitro in murine macrophage cells (raw 264.7 cells) and in Leishmania amazoniensis as well as L. braziliensis promastigotes. Metabolites 1–3 and 5 showed moderate cytotoxicity (between 30–94 μg/mL) but are not responsible for the antileishmanial effect of the extract.
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| 6. |
- Haddadi, Sara, et al.
(författare)
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Building polymer-like clusters from colloidal particles with isotropic interactions, in aqueous solution
- 2021
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Ingår i: Journal of Colloid and Interface Science. - : Elsevier BV. - 0021-9797. ; 581, s. 669-681
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Tidskriftsartikel (refereegranskat)abstract
- Hypothesis: Colloidal particles that interact via a long-ranged repulsive barrier in combination with a very short-ranged attractive minimum can “polymerize” to form highly anisotropic structures. Motivated by previous experimental achievements in non-aqueous solvents, and recent theoretical predictions, we hypothesize that it is possible to construct clusters that resemble linear or branched polymers, in aqueous solution. If these clusters are not too large, they may even remain dispersed, but even if they grow large enough to sediment, they may be collected and used in future applications.Experiments: In this work, we specifically synthesize poly (ethylene glycol) (PEG) chains, grafted onto poly(styrene) (PS) particles in aqueous solution, and adjust the conditions so that strongly anisotropic and isolated polymer-like clusters are formed. These conditions include a very low ionic strength (the particles are weakly charged), a relatively high temperature, and a low particle concentration. An important criterion is that the particle size is large enough to admit structural analyses via confocal laser scanning microscopy (CLSM). We have furthermore utilized Metropolis Monte Carlo (MC) simulation to generate theoretical predictions of these cluster formations. We have conducted such simulations of 3D as well as 2D systems, where the latter is also relevant, given that the clusters sometimes deposit onto the glass surfaces upon imaging. A simplistic particle–particle potential of mean force is adopted for the simulations, but we also invoke a more elaborate theoretical model, to demonstrate that similar interactions can be obtained when the grafted chains are treated explicitly.Findings: According to our Zeta potential measurements, the particles indeed carry a weak negative charge, presumably due to ion specific adsorption. Furthermore, by ensuring that the ionic strength is very low, with a Debye length similar to the particle size, we could use temperature to control the hydrophobicity of the grafted PEG layer, and thus the strength of the short-ranged attraction. We were indeed able to establish highly anisotropic structures, that resemble linear or branched polymers, which we could image by CLSM. The average degree of polymerization could be adjusted by a variation of the particle concentration.
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| 7. |
- Ishchuk, Olena P., et al.
(författare)
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Simple carbohydrate derivatives diminish the formation of biofilm of the pathogenic yeast candida albicans
- 2020
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Ingår i: Antibiotics. - : MDPI AG. - 2079-6382. ; 9:1
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Tidskriftsartikel (refereegranskat)abstract
- The opportunistic human fungal pathogen Candida albicans relies on cell morphological transitions to develop biofilm and invade the host. In the current study, we developed new regulatory molecules, which inhibit the morphological transition of C. albicans from yeast-form cells to cells forming hyphae. These compounds, benzyl α-l-fucopyranoside and benzyl β-d-xylopyranoside, inhibit the hyphae formation and adhesion of C. albicans to a polystyrene surface, resulting in a reduced biofilm formation. The addition of cAMP to cells treated with α-l-fucopyranoside restored the yeast-hyphae switch and the biofilm level to that of the untreated control. In the β-d-xylopyranoside treated cells, the biofilm level was only partially restored by the addition of cAMP, and these cells remained mainly as yeast-form cells.
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| 8. |
- Ishchuk, Olena P., et al.
(författare)
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The use of polyhydroxylated carboxylic acids and lactones to diminish biofilm formation of the pathogenic yeast : Candida albicans
- 2019
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Ingår i: RSC Advances. - : Royal Society of Chemistry (RSC). - 2046-2069. ; 9:19, s. 10983-10989
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Tidskriftsartikel (refereegranskat)abstract
- The vaginal microbiome of healthy women is a diverse and dynamic system of various microorganisms. Any sudden change in microbe composition can increase the vaginal pH and thus lead to vaginal infections, conditions that affect a large percentage of women each year. The most common fungal strains involved in infections belong to the yeast species Candida albicans. The main virulence factor of C. albicans is the ability to transform from planktonic yeast-form cells into a filamentous form (hyphae or pseudohyphae), with the subsequent formation of biofilm. The hyphal form, constituted by filamentous cells, has the ability to invade tissue and induce inflammation. Our hypothesis is that certain polyhydroxylated carboxylic acids, that may serve as an alternative carbohydrate source and at the same time lower the pH, function as an indicator of a nutrient-rich environment for C. albicans, which favors planktonic cells over hyphae, and thus diminish the formation of biofilm. We have shown that the biofilm formation in C. albicans and other Candida species can be significantly reduced by the addition of glucono-δ-lactone (GDL).
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| 9. |
- Limachi, Ivan, et al.
(författare)
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Trichilianones A-D, Novel Cyclopropane-Type Limonoids from Trichilia adolfi
- 2021
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Ingår i: Molecules (Basel, Switzerland). - : MDPI AG. - 1420-3049. ; 26:4
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Tidskriftsartikel (refereegranskat)abstract
- The fractionation of an ethanol extract of the bark of Trichilia adolfi yielded four novel limonoids (trichilinones A-D, 1-4), with five fused rings and related to the hortiolide-type limonoids. Starting with an ε-lactone, which is α,β-unsaturated in trichilinones A and D (1 and 4), attached to a tetrahydrofuran ring that is connected to an unusual bicyclo [5.1.0] hexane system, joined with a cyclopentanone with a 3-furanyl substituent [(2-oxo)-furan-(5H)-3-yl in trichilinone D (4)], the four compounds isolated display a new 7/5/3/5/5 limonoid ring system. Their structures were established based on extensive analysis of NMR spectroscopic data. As the crude extract possessed anti-leishmanial properties, the compounds were assayed for cytotoxic and anti-parasitic activities in vitro in murine macrophages cells (Raw 264.7) and leishmania promastigotes (L. amazoniensis and L. braziliensis), respectively. The compounds showed moderate cytotoxicity (approximately 70 μg/mL), but are not responsible for the leishmanicidal effect of the extract.
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| 10. |
- Lozano, Maribel, et al.
(författare)
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Cytotoxicity of New Damsin Derivatives in Breast Cancer Cells
- 2019
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Ingår i: Journal of Pharmacy & Drug Development. - 2348-9782. ; 1:2
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Tidskriftsartikel (refereegranskat)abstract
- As a follow-up of a previous investigation in which semisynthetic damsin derivatives were shown to possess up to 10 times higher cytoxicity in JIMT-1 breast cancer cells compared to normal breast epithelial MCF-10A cells, a range of new derivatives were prepared and assayed toward the same cells. Damsin, a natural plant metabolite containing a α-methylene-γ-lactone (or 3-methylenedihydro- furan-2(3H)-one) moiety, was modified in position 3 by Claisen-Schmidt condensations with aromatic aldehydes, mainly mono- or disubstituted benzaldehydes, without affecting the α-methylene-γ-lactone function. This lactone ring is a Michael acceptor that is known to affect biological processes such as cell proliferation, death/apoptosis, and cell migration, by interfering with nucleophilic sites in cell signalling pathways. However, although Michael acceptors are reactive, the Michael addition is reversible and it can be assumed that also other parts of the molecules will moderate the binding to and the release from any given nucleophilic site in a protein, and thereby moderate a specific biological activity. In this investigation, the cytotoxicity of 20 α-methylene-γ-lactones towards normal breast epithelial MCF-10A cells as well as breast cancer JIMT-1 cells is compared, by determining the inhibitory concentration 50 (IC50) from dose response curves. The IC50 values in the two cell lines were found to depend on the overall structure of the assayed compounds, although less in this subset of compounds compared to a previous investigation. Structure-activity relationships that may explain the observed differences in potency and selectivity are discussed.
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