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441.
A sensitive and selective HPLC method with coulometric electrode array detection for the determination of pipecuronium bromide and its four impurities has been developed. The coulometric electrode array detection at increasing potentials from +300 to +900mV of the porous graphite electrode versus the palladium reference electrode was used. The limit of detection and quantitation for pipecuronium bromide was 8 and 25ngml(-1), respectively. This elaborate method for the simultaneous analysis of pipecuronium bromide and its impurities proved to be fast, precise, accurate, sensitive, and could be applied to analysis in substances and in pharmaceutical preparations. 相似文献
442.
Aequationes mathematicae - In this paper, we consider the condition $$\sum _{i=0}^{n+1}\varphi _i(r_ix+q_iy)\in {\mathbb {Z}}$$ for real valued functions defined on a linear space V. We derive... 相似文献
443.
Magorzata Tabaszewska Agata Antoniewska Jaroslawa Rutkowska ukasz Skoczylas Jacek Supski Radosawa Skocze-Supska 《Molecules (Basel, Switzerland)》2021,26(15)
This study aimed at assessing the composition of bioactive compounds, including ascorbic acid, carotenoids and polyphenols, the volatile compound profile and the antioxidant activity of red arils (RAs) of Taxus baccata L. grown in diverse locations in Poland. Among the carotenoids assayed in high quantities (3.3–5.42 μg/g), the lycopene content (2.55–4.1 μg/g) was remarkably higher than that in many cultivated fruits. Samples collected from three sites were distinguished by higher amounts of ascorbic acid (125 mg/100 g, on average) than those found in many cultivated berries. Phenylpropanoids quantitatively dominated among the four groups of phenolic compounds. Chromatographic separation enabled the detection of two phenylpropanoid acids: ferulic and p-coumaric. Irrespectively of the growth site, RAs contained substantial amounts of (-)-epicatechin (1080 μg/100 g, on average). A higher ability to scavenge DPPH● and ABTS●+ radicals was found in the hydrophilic fraction of RAs from two sites (Warsaw and Koszalin) compared with the other two sites. The volatile compound profile of RAs was dominated by alcohols, followed by ketones, esters and aldehydes. The presence of some volatiles was exclusively related to the specific growth site, which may be regarded as a valuable indicator. The combination of bioactive and volatile compounds and the fairly good antioxidant potential of RAs render them an attractive source for preparing functional foods. 相似文献
444.
Hottin A Dubar F Steenackers A Delannoy P Biot C Behr JB 《Organic & biomolecular chemistry》2012,10(29):5592-5597
We prepared a series of new iminosugar-ferrocene hybrids displaying potent inhibition of fucosidase (bovine kidney) and inactivation of MDA-MB-231 breast cancer cells proliferation at low micromolar concentrations. The synthetic route brought to light an unprecedented isomerisation of a 2-ethanalylpyrrolidine. 相似文献
445.
Agata Hogendorf Adam S. Hogendorf Rafa Kurczab Grzegorz Sataa Bernadeta Szewczyk Paulina Cielik Gniewomir Latacz Jadwiga Handzlik Tomasz Lenda Katarzyna Kaczorowska Jakub Staro Ryszard Bugno Beata Duszyska Andrzej J. Bojarski 《Molecules (Basel, Switzerland)》2021,26(15)
A series of N-skatyltryptamines was synthesized and their affinities for serotonin and dopamine receptors were determined. Compounds exhibited activity toward 5-HT1A, 5-HT2A, 5-HT6, and D2 receptors. Substitution patterns resulting in affinity/activity switches were identified and studied using homology modeling. Chosen hits were screened to determine their metabolism, permeability, hepatotoxicity, and CYP inhibition. Several D2 receptor antagonists with additional 5-HT6R antagonist and agonist properties were identified. The former combination resembled known antipsychotic agents, while the latter was particularly interesting due to the fact that it has not been studied before. Selective 5-HT6R antagonists have been shown previously to produce procognitive and promnesic effects in several rodent models. Administration of 5-HT6R agonists was more ambiguous—in naive animals, it did not alter memory or produce slight amnesic effects, while in rodent models of memory impairment, they ameliorated the condition just like antagonists. Using the identified hit compounds 15 and 18, we tried to sort out the difference between ligands exhibiting the D2R antagonist function combined with 5-HT6R agonism, and mixed D2/5-HT6R antagonists in murine models of psychosis. 相似文献
446.
Agata Michalska 《Electroanalysis》2012,24(6):1253-1265
This paper is aiming to give a brief overview of recent research in the field of all‐solid‐state, internal solution free, ion‐selective electrodes and reference electrodes, employing conducting polymers or nano‐/microstructures as solid contacts beneath the polymeric, ion‐selective or reference membranes. The emphasis is on papers published in the last five years (after 2006). According to the papers published, poly(3‐octylthiophene) conducting polymer transducers offer highly reliable sensors for various applications, involving demanding analytical approaches and miniature sensors. On the other hand, the search for alternative materials continues: the sensors obtained by placing nano‐/microstructures (conducting polymers but also other materials, like, e.g., carbon nanotubes) underneath the receptor membrane are intensively tested. The recent years have also shown how useful the application of advanced instrumental methods is for the investigation of processes occurring within all‐solid‐state ion‐selective electrodes. 相似文献
447.
Frelek J Górecki M Laszcz M Suszczyńska A Vass E Szczepek WJ 《Chemical communications (Cambridge, England)》2012,48(43):5295-5297
For the first time two crystalline forms of the same compound (linezolid polymorphs) were investigated by means of the solid-phase ECD and VCD spectra. The ECD spectra show distinct differences and the band at 221 nm serves as a diagnostic one because it is present in form II but absent in form III. The VCD spectra strongly differ in the diagnostic carbonyl absorption range exhibiting two relatively strong bands of opposite signs. 相似文献
448.
Ewa Ostrowska-Lig?za Agata Górska Magdalena Wirkowska Piotr Koczoń 《Journal of Thermal Analysis and Calorimetry》2012,110(1):465-471
Milk components are assumed to be uniformly distributed in a concentrate whilst it is being dried. During milk powder production, these components are redistributed in the drying droplets and the powder surface composition is significantly different from that of the bulk of it. The objective of this article was to analyze and compare phase transitions of powdered baby formulas as well as to make a study of their FT-IR spectra. Food powders of different composition were tested by a differential scanning calorimeter (DSC, TA Instruments Q 200) with a normal pressure cell and a System 2000 spectrophotometer. Significant differences were observed in the shape of curves of the mixtures and the agglomerates. The observed phase transitions in powders depended on fat content. Characteristic peaks of melting lactose were observed in the curves of the powdered baby formulas. The IR spectra proved to be useful in determining adulteration of baby formulas. Both methods were complimentary during a thorough evaluation of these food powders. 相似文献
449.
Agata Steenackers Aurélie Cazet Marie Bobowski Yoann Rombouts Jonathan Lefebvre Yann Guérardel David Tulasne Xuefen Le Bourhis Philippe Delannoy 《Comptes Rendus Chimie》2012,15(1):3-14
B- and c-series of gangliosides are over-expressed in neuro-ectoderm-related cancers, including breast cancer. It has been shown that GD3 ganglioside is over-expressed in about 50% of invasive ductal breast carcinoma and the GD3 synthase (GD3S) gene displays higher expression among estrogen receptor (ER) negative breast tumors. We previously showed that GD3S expression in MDA-MB-231 breast cancer cells induces the expression of GD2 and increased cell proliferation and migration via a GD2-dependent activation of c-Met receptor. Here, we show that in ER-positive MCF-7 breast cancer cells, GD3S expression resulted in an increase of GD1b, which was associated with a decrease of GM1a and GM2. Meanwhile, GD3S expressing MCF-7 cells exhibited an increased migration without any modification of proliferation rate. Therefore, GD3S expression can result in different modifications of both ganglioside profiles and cell phenotypes depending on breast cell types. 相似文献
450.
Maciej A. Hodorowicz Agata Piaskowska Katarzyna M. Stadnicka 《Acta Crystallographica. Section C, Structural Chemistry》2012,68(7):m173-m176
catena‐Poly[benzyldecyldimethylammonium [plumbate(II)‐tri‐μ‐bromido]], {(C19H34N)[PbBr3]}n, crystallizes as an inorganic–organic hybrid following monoclinic space‐group symmetry P21/c. The structure consists of extended chains running along the [001] direction and built of [PbBr3]− units. These inorganic chains are separated by interdigitated ammonium cations which form hydrophilic layers through weak C—H...Br interactions. The architecture is essentialy the same as found for n‐alkylbenzyldimethylammonium bromides. 相似文献