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1.
Sarath P. Gunasekera Sofia Kokkaliari Ranjala Ratnayake Thomas Sauvage Larissa A. H. dos Santos Hendrik Luesch Valerie J. Paul 《Molecules (Basel, Switzerland)》2022,27(5)
Dysidazirine carboxylic acid (1) was isolated from the lipophilic extract of a collection of the benthic marine cyanobacterium Caldora sp. from reefs near Fort Lauderdale, Florida. The planar structure of this new compound was determined by spectroscopic methods and comparisons between HRMS and NMR data with its reported methyl ester. The absolute configuration of the single chiral center was determined by the conversion of 1 to the methyl ester and the comparison of its specific rotation data with the two known methyl ester isomers, 2 and 3. Molecular sequencing with 16S rDNA indicated that this cyanobacterium differs from Caldora penicillata (Oscillatoriales) and represents a previously undocumented and novel Caldora species. Dysidazirine (2) showed weak cytotoxicity against HCT116 colorectal cancer cells (IC50 9.1 µM), while dysidazirine carboxylic acid (1) was non-cytotoxic. Similar cell viability patterns were observed in RAW264.7 cells with dysidazirine only (2), displaying cytotoxicity at the highest concentration tested (50 µM). The non-cytotoxic dysidazirine carboxylic acid (1) demonstrated anti-inflammatory activity in RAW264.7 cells stimulated with LPS. After 24 h, 1 inhibited the production of NO by almost 50% at 50 µM, without inducing cytotoxicity. Compound 1 rapidly decreased gene expression of the pro-inflammatory gene iNOS after 3 h post-LPS treatment and in a dose-dependent manner (IC50 ~1 µM); the downregulation of iNOS persisted at least until 12 h. 相似文献
2.
We determined the feasibility of using capillary electrophoresis with postcolumn laser-induced fluorescence (CE-LIF) detection to characterize electrophoretic properties of isolated cell nuclei and impurities present in nuclear fractions. These fractions were isolated from NS-1 mouse hybridoma cells, stained with hexidium iodide, a DNA intercalating dye, and analyzed by CE-LIF detection. The corresponding electropherograms display two features: (i) broad peaks (6-90 s wide) caused by the cell culturing media and by free-DNA intercalated with hexidium iodide, and (ii) a large number of narrow peaks (180 ms wide), resulting from DNA associated with individual intact or disrupted nuclei. We confirmed that the narrow peaks were not caused by contaminating mitochondria. The overall electrophoretic mobility range of disrupted nuclei is 0 to -5 x 10(-4)cm(2)/Vs, while intact nuclei seem to have mobilities in the -1.5 to -3.5 x 10(-4)cm(2)/Vs range. Furthermore, the highly sensitive CE-LIF method reveals a high abundance of disrupted nuclei that cannot be directly observed by confocal microscopy. 相似文献
3.
A facile synthesis of 2,3-disubstituted-6-arylpyridines from enaminones using montmorillonite K10 as solid acid support is reported herein. 相似文献
4.
Sachini Rodrigo Disni Gunasekera Jyoti P. Mahajan Long Luo 《Current Opinion in Electrochemistry》2021
Electrochemical organic synthesis has recently attracted much attention because of its unique reactivity and environmentally benign approach. Conventional electrosynthesis uses either constant current or constant potential, known as direct current electrolysis. However, recently, alternating current electrolysis has begun receiving more attention. The purpose of this study is to give a short overview of the history and recent advances in the field of alternating current electrolysis for organic synthesis. 相似文献
5.
Ching-Min Chang Marian W. Kemblowski Jagath J. Kaluarachchi Alaa Abdin 《Transport in Porous Media》1995,19(3):233-259
Stochastic analysis of steady-state two-phase (water and oil) flow in heterogeneous porous media is performed using the perturbation theory and spectral representation techniques. The governing equations describing the flow are coupled and nonlinear. The key stochastic input variables are intrinsic permeability,k, and the soil and fluid dependent retention parameter, . Three different stochastic combinations of these two imput parameters were considered. The perturbation/spectral analysis was used to develop closed-form expressions that describe stochastic variability of key output processes, such as capillary and individual phase pressures and specific discharges. The analysis also included the estimation of the effective flow properties. The impact of the spatial variability ofk and on the variances of pressures, effective conductivities, and specific discharges was examined. 相似文献
6.
Dinara S. Gunasekera Nathan S. Aalderks J. Subash Chandra Christiana A. Maanu Viktor V. Zhdankin 《Tetrahedron》2007,63(38):9401-9405
A convenient one-pot synthesis of benzoboroxoles has been developed via the reaction of o-bromobenzyl alcohols with NaH, nBuLi, and B(OiPr)3 followed by acidic hydrolysis. Applications of these benzoboroxoles have been demonstrated in Pd-catalyzed cross-coupling reactions and the protocol has been extended for the synthesis of a chiral benzoboroxole. Exceptionally short synthesis of a potent antifungal agent AN2690 and several of its analogs has also been realized. 相似文献
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8.
Philip W. Westerman Sarath P. Gunasekera M. Uvais S. Sultanbawa Rymantas Kazlauskas 《Magnetic resonance in chemistry : MRC》1977,9(11):631-636
The 13C n.m.r. spectra of 36 naturally occurring xanthones are reported and all chemical shifts assigned. The shifts in substituted xanthones can be predicted from substituent effects evaluated for simple derivatives. The agreement between calculated and observed shifts decreases as the extent of substitution in the xanthone increases. 相似文献
9.
Karunarathne K. A. Janani K. Perera Kumudu S. Vidanapathirana Kamal P. Pitawela Jagath C. 《Journal of Solid State Electrochemistry》2019,23(7):2165-2171
Journal of Solid State Electrochemistry - Super capacitors have emerged as a promising substitute for batteries and conventional capacitors which have played a key role as energy storage devices.... 相似文献
10.
Several substituted 7-(2′-hydroxybenzoyl)-3-phenyl-1,2,4-triazolo[3,4-b][1,3,4]thiadiazepines are synthesised by reacting 3-formylchromones with 4-amino-3-mercapto-5-phenyl-1,2,4-triazole under phase transfer catalysis conditions. 相似文献