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111.
ukasz Pecio Asmaa M. Otify Fatema R. Saber Yasser A. El-Amier Moataz Essam Shalaby Solomiia Kozachok Amira K. Elmotayam ukasz
witek Adrianna Skiba Krystyna Skalicka-Wo
niak 《Molecules (Basel, Switzerland)》2022,27(21)
Iphiona mucronata (Family Asteraceae) is widely distributed in the Eastern desert of Egypt. It is a promising plant material for phytochemical analysis and pharmacologic studies, and so far, its specific metabolites and biological activity have not yet been thoroughly investigated. Herein, we report on the detailed phytochemical study using UPLC-Q-TOF-MS approach. This analysis allowed the putative annotation of 48 metabolites belonging to various phytochemical classes, including mostly sesquiterpenes, flavonoids, and phenolic acids. Further, zebrafish embryotoxicity has been carried out, where 100 µg/mL extract incubated for 72 h resulted in a slow touch response of the 10 examined larvae, which might be taken as a sign of a disturbed peripheral nervous system. Results of in vitro testing indicate moderate cytotoxicity towards VERO, FaDu, and HeLa cells with CC50 values between 91.6 and 101.7 µg/mL. However, selective antineoplastic activity in RKO cells with CC50 of 54.5 µg/mL was observed. To the best of our knowledge, this is the first comprehensive profile of I. mucronata secondary metabolites that provides chemical-based evidence for its biological effects. A further investigation should be carried out to precisely define the underlying mechanisms of toxicity. 相似文献
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115.
Edyta Piskorska Krystyna Lawniczak-Jablonska Iraida N. Demchenko Ewa Benko Markku Heinonen 《Mikrochimica acta》2004,145(1-4):159-163
X-ray photoelectron spectroscopy (XPS) is used to estimate phase and element contents of the composites based on cubic boron nitride. A composite is a mixture of several compounds and the use of traditional X-ray diffraction for phase analysis in many cases can be difficult. By using XPS, we were able to evaluate the atomic concentration of elements and the content of different compounds of each element. SEM and XPS showed that samples are heterogeneous. The TiB2 phase, expecting from thermodynamic calculations, was formed in both investigated samples of cBN/Ti3SiC2/TiC but in different amount. The Ti3SiC2 additive was found more chemically active then TiC. 相似文献
116.
Katarzyna Dopierała Monika Rojewska Marta Skrzypiec Michał Dutkiewicz Hieronim Maciejewski Krystyna Prochaska 《Liquid crystals》2018,45(3):351-361
Polyhedral oligomeric silesquioxanes (POSS) with eight polyether substituents were mixed with the liquid crystal (LC) 4-octyloxy-4′-cyanobiphenyl and spread at the air/water interface. The surface pressure-area and surface potential-area isotherms were recorded for different weight ratios of both components. The obtained results showed that POSS molecules had beneficial influence on LC monolayer improving its stability and rigidity. Moreover, it was found that some LC–POSS mixtures collapse reversibly and form multilayer films on the top of LC monolayer. On the other hand, interfacial dilatational and shear rheology indicated decrease of elasticity of the films after mixing. Brewster angle microscopy revealed multilayer structure of the condensed film and formation of net-like structures in the expanded film. These films were successfully transferred on solid substrates using the Langmuir–Blodgett technique. The scanning electron microscopy images confirmed the film deposition and formation of networks by POSS–LC mixtures. These findings may be useful in the fabrication of electronic devices based on LCs. 相似文献
117.
Summary Two complexes formed from CuII acetate and thiazolidine-4-carboxylic acid (4-TCA) and 2-amino-4-thiazoleethanoic acid (ATAA) have been prepared and characterized by magnetic and spectroscopic techniques. The influence of the nature of ligands and solvents upon CuII e.p.r. properties was investigated for these compounds, Spin-Hamiltonian parameters from these data enabled suggestions concerning the structure of these complexes and the binding ability of the ligands. 相似文献
118.
Adam Bieniek Jan Epsztajn Krystyna K. Kulikiewicz 《Monatshefte für Chemie / Chemical Monthly》2004,38(Z1):69-77
A convenient two-step protocol preparation of ortho-alkylated (substituent with the carbomethoxy group at the end of five carbon atoms alkyl chain) aromatic carboxylic acids from benzoic acids anilides is described. Ortho-lithiation of benzanilides and subsequent reaction of the generated bis(N- and C-ortho-)-lithiated anilides with aromatic aldehydes provided 3-arylphthalides. In the next step, these phthalides were converted into 5-(2-carboxyphenyl)-5-phenylpent-2-enoic acids by treatment with 1-methoxy-1-trimethylsilyloxybuta-1,3-diene. 相似文献
119.
Fritz G. Will Krystyna Cedzynska Denton C. Linton 《Journal of Electroanalytical Chemistry》1993,360(1-2)
Reproducible tritium generation well above background has been observed in tightly closed D2SO4-containing cells in four out of four Pd wire cathodes of one type. Tritium analysis was performed before and after each experiment on the Pd, the electrolyte and the gas in the head space. No tritium generation was observed in four identical Pd cathodes in H2SO4 cells operated at the same time under the same conditions. A cyclic loading-unloading regime with low current densities, rather than the usual continuous constant current regime, was employed to attain D/Pd and H/Pd loadings of 1±0.05 reproducibly. D/Pd loadings greater than 0.8±0.05 appear to be necessary to generate tritium. The largest amount of tritium, generated in 7 days of continuous electrolysis, was 2.1 × 1011 tritium atoms, compared with a background of 4 × 109 tritium atoms. The concentration of tritium and its axial distribution in the Pd were determined and concentrations of up to 9 × 1010 atoms/g Pd were found compared with a maximum background of 5 × 108 atoms g−1. The T/D ratio in the Pd is about 100 times larger than in the electrolyte or gas and indicates that tritium generation occurs in the Pd interior rather than at its surface. No tritium generation was observed in two other types of Pd electrodes in D2SO4, despite the attainment of D/Pd ratios near 1:1. Thus high D/Pd ratios appear to be a necessary but not sufficient condition for tritium generation in D2SO4 electrolysis. 相似文献
120.
The possibility of selective preconcentration of platinum group metal ions by Donnan dialysis was investigated. The effect of sample matrix (glycine) on self diffusion of the following platinum group metal ions Pt(IV), Pd(II), Rh(III), Ir(III) and Ir(IV) was determined. To separate a sample from the receiver electrolyte (0.5M NH4Cl), anion or cation-exchange membrane were used. Excellent selective preconcentration of Pd(II) in the sample and Ir(III) in the receiver solution was achieved. Experiments performed enable to draw some conclusion on the charge sign of glycinepalladium complexes. 相似文献