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201.
Singh AJ Razzak M Teesdale-Spittle P Gaitanos TN Wilmes A Paterson I Goodman JM Miller JH Northcote PT 《Organic & biomolecular chemistry》2011,9(12):4456-4466
Two new peloruside congeners (3 and 4) were isolated from wild and aquacultured collections of the New Zealand marine sponge Mycale hentscheli. Small-scale reactions on peloruside A (1) have been performed, which along with the isolation of 3 and 4, give further insight into the bioactive pharmacophore of 1. 相似文献
202.
Abderrahman El Bouakher Gildas PriéMina Aadil Said LazarMohamed Akssira Marie-Claude Viaud-Massuard 《Tetrahedron》2012,68(47):9572-9577
A novel methodology has been developed for the efficient synthesis of 1,4-pyridopyrrolodiazepine derivatives. The key reaction is the bromination under mild conditions by NBS of compounds resulting via peptide coupling of l-proline methyl ester with 3-aminopyridine-2-carboxylic acid 1, then intramolecular cyclization in the construction of 2-bromo-6a,7,8,9-tetrahydro-5H-pyrido[3,2-e]pyrrolo[1,2-a][1,4]diazepine-6,11-dione 4. This latter is then engaged in cross-coupling reactions to generate 1,4-pyridopyrrolodiazepines derivatives 5a-m, 6a-i, 7, and 8a-c. This strategy provides an efficient method to access a library of compounds based on privileged substructures that are of great interest in drug discovery. 相似文献
203.
Nahla Zanina Soumaya Haddad Ali Othmane Thierry Jouenne David Vaudry Mina Souiri Laurence Mora 《Chemical Papers》2012,66(5):532-542
The seeding of endothelial cells on biomaterial surfaces has become a major challenge to achieve better haemocompatibility
of these surfaces. Multilayers of polyelectrolytes formed by the layerby-layer method are promising in this respect. In this
study, the interactions of endothelial cells with multilayered polyelectrolytes films were investigated. The build-ups were
prepared by selfassembled alternatively adsorbed polyanions and polycations functionalised with fibronectin and collagen.
Anionic poly(sodium 4-styrenesulfonate) and cationic poly(allylamine hydrochloride) polyelectrolytes were chosen as a model
system. Elaborated surfaces were characterised by electrochemical impedance spectroscopy and cyclic voltammetry. The modified
electrode showed good reversible electrochemical properties and high stability in an electrolyte solution. The film ohmic
resistance was highest when the film was coated with fibronectin; the parameters so determined were correlated with atomic
force microscopy images. Cell colorimetric assay (WST-1) and immunofluorescence were used to quantify the cell viability and
evaluate the adhesion properties. When cultured on a surface where proteins were deposited, cells adhered and proliferated
better with fibronectin than with collagen. In addition, a high surface free energy was favourable to adhesion and proliferation
(48.8 mJ m−2 for fibronectin and 39.7 mJ m−2 for collagen, respectively). Endothelial cells seeded on functionalised-polyelectrolyte multilayer films showed a good morphology
and adhesion necessary for the development of a new endothelium. 相似文献
204.
Tsutomu Asano Tomohiko Yamamoto Mohammad Forhad Mina Yasuna Fujiwara Hiroshi Takahashi Ichiro Hatta 《Journal of Macromolecular Science: Physics》2013,52(1-2):163-175
Isotactic polypropylene consisting of uniaxially oriented P-phase lamellae was crystallized in a temperature gradient. The β → α transition was investigated by simultaneous measurements with differential scanning calorimetry (DSC) and X-ray diffraction using synchrotron radiation (SR). To compare the transition mechanism, the β-phase sample was deformed by rolling it along the direction of the crystallization. During rolling, the β-crystal is deformed by interlamellar and interchain slip, which induces c-axis-oriented molecules along the rolling direction. The melting behavior is changed by the rolling deformation. For the as-grown β-crystal, the DSC thermogram has three peaks: the β-melting endotherm at 150°C, an exotherm by recrystallization into the °-form, and the endotherm at 167°C caused by melting of the recrystallized α-form. After the rolling deformation, the β-endotherm is extinguished by the successive exotherm. Simultaneous X-ray measurements reveal that the β → α transition is shifted to a lower temperature and that the recrystallized α-form has a c-axis-orientation caused by the rolling deformation. In the process of the β→ α transition, higher-order lamellar structure is developed earlier than formation of the crystalline structure. In this study, the heating phenomena, such as the β α transition and thickening of the β- and α-lamellae, are consistently explained by a mechanism involving melting and subsequent recrystallization. 相似文献
205.
Species of Podocarpus are used traditionally in their native areas for the treatment of fevers, asthma, coughs, cholera, chest pain, arthritis, rheumatism, and sexually transmitted diseases. To identify natural products having efficacy against inflammatory bowel disease (IBD), we identified a new, 16-hydroxy-4β-carboxy-O-β-D-glucopyranosyl-19-nor-totarol (4) together with three known diterpenoids from P. macrophyllus. Furthermore, all the extracts, fractions, and isolates 1–4 were investigated for their anti-inflammatory effects by assessing the expression on nitric oxide (NO) production and proinflammatory cytokines in lipopolysaccharide (LPS)-stimulated RAW 264.7 and HT-29 cells. Among them, nagilactone B (2) exhibited a potent anti-inflammatory effect against NO production on RAW 264.7 cells; therefore, nagilactone B was further assessed for anti-inflammatory activity. Western blot analysis revealed that nagilactone B significantly decreased the expression of LPS-stimulated protein, inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2, and phosphorylated extracellular regulated kinase (pERK)1/2. In addition, nagilactone B downregulated tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-8 levels in LPS-induced macrophages and colonic epithelial cells. To our best knowledge, this is the first report on the inhibitory effect of nagilactone B (pure state) and rakanmakilactone G against NO production in LPS-stimulated RAW 264.7 cells. Thus, diterpenoids isolated from P. macrophyllus could be employed as potential therapeutic phytochemicals for IBD. 相似文献
206.
Mina K Parida 《Pramana》2012,79(5):1271-1274
In SO(10), the type-I and type-II see-saw scales ???1012 GeV are far away from being probed by direct experimental tests. In the absence of supersymmetry, we show how experimentally verifiable radiative see-saw formula of Ma type is realized in non-SUSY SO(10) while fulfilling the twin objectives: precision gauge coupling unification and dark matter. This model is expected to have a dramatic impact on neutrino physics, dark matter and all fermion masses and mixings. 相似文献
207.
Mina Zarei 《Physica A》2009,388(8):1721-1730
We propose a general spectral method to find communities of a network based on network complement and anti-community concepts. Analytical and numerical results show that the eigenspace of matrices corresponding to a network complement reveals the community structure of a network more accurately than the eigenspace of matrices corresponding to the network itself. It is shown that the Laplacian eigenspace is the best candidate for spectral community detection especially in networks with a heterogeneous community structure. The method is applied to some computer-generated and real-world networks with known community structures. 相似文献
208.
209.
Iman SAEIDI Behruz BARFI Moazameh PAYROVI Javad FEIZY Hojat A SHEIBANI Mina MIRI Farahnaz GHOLLASI MOUD 《色谱》2015,33(1):29-34
With polyamide( PA)as an efficient sorbent for solid phase extraction( SPE)of Sudan dyes II,III and Red 7B from saffron and urine,their determination by HPLC was performed. The optimum conditions for SPE were achieved using 7 mL methanol/water( 1:9,v/v,pH 7)as the washing solvent and 3 mL tetrahydrofu-ran for elution. Good clean-up and high( above 90%)recoveries were observed for all the analytes. The opti-mized mobile phase composition for HPLC analysis of these compounds was methanol-water( 70:30,v/v). The SPE parameters,such as the maximum loading capacity and breakthrough volume,were also determined for each analyte. The limits of detection( LODs),limits of quantification( LOQs),linear ranges and recoveries for the analytes were 4. 6-6. 6 μg/L,13. 0-19. 8 μg/L,13. 0-5 000 μg/L( r2> 0. 99)and 92. 5% -113. 4%,respec-tively. The precisions( RSDs)of the overall analytical procedure,estimated by five replicate measurements for Sudan II,III and Red 7B in saffron and urine samples were 2. 3%,1. 8% and 3. 6%,respectively. The developed method is simple and successful in the application to the determination of Sudan dyes in saffron and urine sam-ples with HPLC coupled with UV detection. 相似文献
210.
Uncatalyzed reaction of epoxides with (aminomethyl)phosphonates for the synthesis of novel {[(2‐hydroxyethyl)amino]methyl}phosphonates is described. Treatment of (aminomethyl)phosphonates with epoxides without any catalyst and under solvent‐free conditions gives novel {[(2‐hydroxyethyl)amino]methyl}phosphonates. Using this method, a series of {[(2‐hydroxyethyl)amino]methyl}phosphonates was synthesized in good yields. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 21:284–289, 2010; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20615 相似文献