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981.
Monika Skrutková Langmajerová Marta Pelcová Pavla Vedrová Andrea Celá Zdeněk Glatz 《Electrophoresis》2022,43(5-6):679-687
Monitoring metabolite uptake and excretion in the culture medium is a noninvasive technique that is used for the metabolic study of cleaving embryos after in vitro fertilization. Low sample consumption, the versatility of the detection, and optimal sensitivity and selectivity are essential elements for extracellular metabolome analyses, and can be conveniently achieved by combining CE with mass spectrometric detection. This paper reports a method for amino acid determination in a limited volume sample (8 μL) of spent culture media collected after the cultivation of in vitro fertilized embryos. Special attention was focused on the sample preparation procedure. The sample was processed with acetonitrile, which facilitates online sample preconcentration via field-amplified sample stacking, and undesired sample evaporation was significantly reduced by the simultaneous addition of dimethyl sulfoxide. Key parameters that affected electrophoretic separation and mass spectrometric detection were investigated, including the type of buffers and organic solvent, optimization of their concentrations, and finally the settings for their ionization. The separation and quantification of 19 amino acids were achieved using 15% acetic acid as the background electrolyte with a sheath liquid consisting of an equimolar mixture of methanol and water. The applicability of the optimized system was demonstrated by determining the amino acid profile in 40 samples of spent cultivation medium in this pilot study. This developed method also has great potential for amino acid analyses in minute sample volumes of other biological matrices. 相似文献
982.
Budi Prasaja Yahdiana Harahap Windy Lusthom Anna Sofiana Falah Safira Monika Sandra Girinanda Puspanegara 《Biomedical chromatography : BMC》2019,33(2)
Beraprost sodium is an oral prostacyclin analog that was first approved in 1992 (Japan) for the treatment of peripheral vascular disorders. It is administered orally as a tablet available in strength 20 μg. In this paper, we described a liquid chromatography tandem mass spectrometry method that was developed for the quantification of beraprost in human plasma with high sensitivity at picogram per milliliter concentration. The method had been validated in terms of selectivity, sensitivity, accuracy and precision, matrix effect, linearity, recovery and carry‐over according to the Guideline on Bioanalytical Validation from the European Medicines Agency. The standard calibration curve for beraprost was 9.5–1419 pg/mL. This method has been applied successfully to a bioequivalence study with 60 μg of beraprost (three tablets) in 29 healthy volunteers. The results showed that the two formulations of beraprost are bioequivalent. 相似文献
983.
Izabela Muszalska Monika A. Lesniewska-Kowiel Katarzyna Becla Wojciech Duda Anna Pawełczyk Katarzyna Sowa-Kasprzak Dorota Olender 《国际化学动力学杂志》2019,51(5):346-357
The stress tests as well as photostability analysis in solutions and the solid phase of the oleanoyl oxime ibuprofenate (Ibu-OxOA) were determined according the International Conference on Harmonization guidelines. For observation of the degradation of tested compounds, the reversed phase high-performance liquid chromatography (RP-HPLC) method was used. The study included the effect of temperature, water, H+ and OH− ions, hydrogen peroxide, and light (6.0 × 106, 1.2 × 106 lux·h) on the stability of the tested hybrid. Studies have shown that these compounds are not stable in a neutral, acidic, or oxidizing medium; very unstable in an alkaline medium; and photostable in a solution and photostable in the solid phase. Studies on the enzymatic stability of the tested hybrid showed that it is not susceptible to degradation in the presence of plasma enzymes as well as in the presence of esterase (37°C, 80% human plasma). The degradation of this compound was observed in the presence of lipase (from Candida antarctica), and the linear dependence of the determined kinetic parameters of the reaction on the enzyme activity was demonstrated. 相似文献
984.
Monika Sharma Shrestha Shrivastva Manish Kumar Shobhit Rabbani Syed Arman Garg Arun 《Journal of Cluster Science》2022,33(6):2589-2600
Journal of Cluster Science - The aim of present study was to develop and evaluate novel in situ nanoemulgel (NEG) of azithromycin (AZM) with eugenol for intra-pocket drug delivery for the treatment... 相似文献
985.
Monika M. G. Bai Dr. K. Bramhaiah Prof. Dr. Santanu Bhattacharyya Prof. Dr. Rajeswara M. Rao 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(61):e202202023
Simple synthetic modifications that tune the molecular structures, thereby the properties of the molecules, are of topical interest. Herein, we report the synthesis of two novel cationic rosaniline-based conjugated microporous polymers (CMPs) from identical monomers via simple acid modulation (Acetic acid and BF3 ⋅ Et2O). The condensation reaction of rosaniline with 2,4,6-triformylphloroglucinol in acetic acid renders β-ketoenamine-linked CMP ( CMP-A ) while changing the acid to BF3 ⋅ Et2O, the linkages transform to enol and undergoes BF2-complexation, leading to boranil CMP ( CMP-B ). BF2-functionalities in boranil CMP significantly modified the optical and functional properties compared to β-ketoenamine-linked CMP. The cationic-delocalization along with the extended π-delocalization supported by chromophoric BF2-groups allow CMP-B to exhibit broad absorption spanning the visible to Near-Infrared region (NIR). The absorption red-edge of CMP-B appears around 1277 nm (optical band gap ∼1.58 eV) while CMP-A displays at 981 nm (optical band gap ∼1.83 eV). Most interestingly, as a photocatalyst, CMP-B catalyzes hydrogen evolution with a superior rate of 252 μmol g−1 over CMP-A (100 μmol g−1). It is about 2.5 times higher performance. The transient photocurrent measurements, electrochemical impedance data, and in-depth mott-Schottky analysis demonstrate that the BF2-group in CMP-B generates photoinduced charge carriers and their migration towards the active sites for photocatalysis. These polymers show significant photocatalytic H2 generation without any supportive metal co-catalyst. The BF2 complexed building blocks are a unique class of metal-free photocatalysts for hydrogen evolution through green and cost-effective approach. 相似文献
986.
Ion‐exchange vs reversed‐phase chromatography for separation and determination of basic psychotropic drugs 下载免费PDF全文
Anna Petruczynik Karol Wróblewski Michał Deja Monika Waksmundzka‐Hajnos 《Biomedical chromatography : BMC》2015,29(11):1700-1707
Ion exchange chromatography, an alternative to reversed‐phase (RP) chromatography, is described in this paper. We aimed to obtain optimal conditions for the separation of basic drugs because silica‐based RP stationary phases show silanol effect and make the analysis of basic analytes hardly possible. The retention, separation selectivity, symmetry of peaks and system efficiency were examined in different eluent systems containing different types of buffers at acidic pH and with the addition of organic modifiers: methanol and acetonitrile. The obtained results reveal a large influence of the salt cation used for buffer preparation and the type of organic modifier on the retention behavior of the analytes. These results were also compared with those obtained on an XBridge C18 column. The obtained results demonstrated that SCX stationary phases can be successfully used as alternatives to C18 stationary phases in the separation of basic compounds. The most selective and efficient chromatographic systems were applied for the quantification of some psychotropic drugs in fortified human serum samples. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
987.
Katarína Klubicová Monika Szabová Ludovit Skultety Gabriela Libiaková Andrea Hricová 《Chemical Papers》2016,70(10):1322-1335
Amaranth, a staple food source in ancient Aztec, Maya and Inca cultures, has been recognised as a 21st century crop. This superfood, known as Inca wheat, attracts the worldwide attention of researchers and farmers for its superior agronomical and technological properties but especially because of its exceptional nutritive value. A combination of two-dimensional electrophoresis (2-DE) with MS facilitating the effective differentiation of 13 classes of Amaranthus cruentus L. “Ficha” mature seed proteins was used in the current study. The best resolution results in the 2-DE were obtained using immobilised pH gradients strips with a pH range of 5–8. Out of the 461 spots detected, 249 were successfully identified by LC-MS/MS analysis, making this the most inclusive protein profile of mature amaranth seed. Unknown proteins represented the most abundant class of proteins (59), the second most abundant category was related to energy (46) and then to seed storage proteins (43). These results expand the knowledge of the amaranth seed proteome and it is expected that the data presented here will contribute to further in-depth characterisation of Amaranthus seeds. 相似文献
988.
Dipak K. Hazra Rajarshi Chatterjee Mahammad Ali Monika Mukherjee 《Acta Crystallographica. Section C, Structural Chemistry》2010,66(4):o190-o193
The molecular structure of the title salt, C11H17N4+·H2PO4−, has been determined from single‐crystal X‐ray analysis and compared with the structure calculated by density functional theory (DFT) at the BLYP level. The crystal packing in the title compound is stabilized primarily by intermolecular N—H...O, O—H...N and O—H...O hydrogen bonds and π–π stacking interactions, and thus a three‐dimensional supramolecular honeycomb network consisting of R42(10), R44(14) and R44(24) ring motifs is established. The HOMO–LUMO energy gap (1.338 eV; HOMO is the highest occupied molecular orbital and LUMO is the lowest unoccupied molecular orbital) indicates a high chemical reactivity for the title compound. 相似文献
989.
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