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991.
992.
Katarzyna Brodowska Anna Sykuła Eugenio Garribba Elżbieta Łodyga-Chruścińska Michał Sójka 《Transition Metal Chemistry》2016,41(2):179-189
A Schiff base derived from naringenin (NTSC) and its complex with Cu(II) ([Cu(H3L)(OAc)]·H2O, Cu(II)–NTSC) have been synthesized and characterized by physicochemical and spectroscopic methods. EPR studies confirmed that nitrogen, oxygen, and sulfur are the donor atoms bound to Cu(II) in the complex. The geometry of the complex has been modelled using DFT methods. Furthermore, naringenin and NTSC were used for the formation of Cu(II) complexes in solution, for comparison of biological activities. Antioxidant studies confirmed better radical scavenging activity of both NTSC and its Cu(II) complex compared to naringenin. The interaction of these compounds with calf thymus DNA was monitored by UV–Vis spectroscopy. 相似文献
993.
Heli Sirén Samira El Fellah 《International journal of environmental analytical chemistry》2016,96(11):1003-1021
Partial-filling micellar electrokinetic capillary chromatography (PF-MEKC) with UV detection was applied for determination of human-based steroids in water samples of Finnish wastewater treatment plants. The samples were purified with solid-phase extraction (SPE) on octadecyl substituted polymer sorbents obtaining analyte enrichment of 20,000-fold. The steroids studied were androgens, estrogens, and progesterone. Three of the steroids could be quantified with the PF-MEKC method. The detection and quantification limits were 0.05–1.06 μg/mL and 0.15–3.2 μg/mL, meaning in the SPE concentrates as 2.5–53 pg/L and 7.5–160 pg/L, respectively. In the influent waters, the total amount of testosterone glucuronide, androstenedione, and progesterone was up to 350 ng/L. In effluent water samples the total steroid quantity was maximum at 320 ng/L. Remarkably high quantity of androstenedione was quantified in both influent and effluent water samples. The cleanest effluent waters were produced in Western Finland. Correspondingly, the highest quantities were located near the largest lake and river areas in South-Eastern Finland. The concentration variation in effluent waters was explained with differences in the purification materials and processes at the plants and with steroid adsorption on soil and organic material suspended into water. 相似文献
994.
Nadia Zekri Nadia Handaq Abdelhamid El Caidi Touria Zair Mohamed Alaoui El Belghiti 《Research on Chemical Intermediates》2016,42(3):1639-1649
Essential oils proved their efficiency as natural insecticides to fight many pests of stored products and crops whereas the hydrosols have not been evaluated yet. The objective of this work is to assess the insecticidal effect of hydrosols extracted from Mentha suaveolens Ehrh. and Mentha pulegium L. toward an insect pest of citrus, Toxoptera aurantii (Homoptera, Aphididae). The extraction of hydrosols was carried out by hydro-distillation using Clevenger apparatus and then the chemical composition was identified by gas chromatography coupled with mass spectrometry. The chemical composition of two hydrosols revealed the abundance of hydrophilic and oxygenated compounds as piperitenone oxide and carvacrol. Different concentrations of each hydrosol were separately diluted in distilled water and applied topically to aphids. The results of this investigation have shown a high insecticidal effect, and the M. suaveolens hydrosol is more effective against citrus pests than that of M. pulegium L. Consequently, these natural compounds can be used in the management of aphids on citrus. 相似文献
995.
Salama Nahla N. Zaazaa Hala E. Abd El Halim Lobna M. Salem Maissa Y. Abd El Fattah Laila E. 《平面色谱法杂志一现代薄层色谱法》2016,29(3):176-183
JPC – Journal of Planar Chromatography – Modern TLC - A rapid, inexpensive, and stereoselective densitometric—thin-layer chromatographic (TLC) method using l-(+)-tartaric acid and... 相似文献
996.
Anion Directed Self‐Assembly of One‐Dimensional and Two‐Dimensional Coordination Polymers Containing Bridging Diphosphine Ligands
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Omar Bin Shawkataly Nur Fatiha Amat Sani Mohd. M. Rosli Mohd. R. Razali 《无机化学与普通化学杂志》2016,642(5):419-423
The reactions of 1,2‐bis(diphenylphosphanyl)ethane (dppe) with different silver(I) salts facilitated the formation of 1D and 2D coordination polymers, [Ag(dppe)(OAc)]n · nH2O ( 1 ) and [Ag2(dppe)1.5(NO3)2]n ( 2 ), respectively. The complexes were characterized by elemental analysis, ATR‐IR spectroscopy, 1H NMR, 13C NMR, and 31P NMR spectroscopy, and single‐crystal X‐ray diffraction. Structural analysis revealed that complex 1 exhibits a 1D infinite wavy structure, in which each silver(I) ion is bridged by dppe ligands. Structure 2 has a 2D topologically promising architecture that displays a 6.6.6 graphitic net, which corresponds to hnd topology. The nitrate ions and dppe ligands are in a μ2 bridging mode and support the formation of this net. Moreover, significant π–π interactions between the phenyl rings in the apertures of (6,3) grid stabilized complex 2 . 相似文献
997.
Markus Nachbar Sami El Deeb Mona Mozafari Hassan A. Alhazmi Lutz Preu Sabine Redweik Wolf Dieter Lehmann Hermann Wätzig 《Electrophoresis》2016,37(5-6):744-751
Strong, sequence‐specific gas‐phase bindings between proline‐rich peptides and alkaline earth metal ions in nanoESI‐MS experiments were reported by Lehmann et al. (Rapid Commun. Mass Spectrom. 2006, 20, 2404–2410), however its relevance for physiological‐like aqueous phase is uncertain. Therefore, the complexes should also be studied in aqueous solution and the relevance of the MS method for binding studies be evaluated. A mobility shift ACE method was used for determining the binding between the small peptide GAPAGPLIVPY and various metal ions in aqueous solution. The findings were compared to the MS results and further explained using computational methods. While the MS data showed a strong alkaline earth ion binding, the ACE results showed nonsignificant binding. The proposed vacuum state complex also decomposed during a molecular dynamic simulation in aqueous solution. This study shows that the formed stable peptide–metal ion adducts in the gas phase by ESI‐MS does not imply the existence of analogous adducts in the aqueous phase. Comparing peptide–metal ion interaction under the gaseous MS and aqueous ACE conditions showed huge difference in binding behavior. 相似文献
998.
Sami El Deeb Hermann Wätzig Deia Abd El‐Hady Cari Sänger‐van de Griend Gerhard K. E. Scriba 《Electrophoresis》2016,37(12):1591-1608
This review updates and follows‐up a previous review by highlighting recent advancements regarding capillary electromigration methodologies and applications in pharmaceutical analysis. General approaches such as quality by design as well as sample injection methods and detection sensitivity are discussed. The separation and analysis of drug‐related substances, chiral CE, and chiral CE‐MS in addition to the determination of physicochemical constants are addressed. The advantages of applying affinity capillary electrophoresis in studying receptor–ligand interactions are highlighted. Finally, current aspects related to the analysis of biopharmaceuticals are reviewed. The present review covers the literature between January 2013 and December 2015. 相似文献
999.
In this second part of the series of investigations involving the postpolymerization modification of a hydroxy monolith (OHM) capillary column, the surface hydroxyl groups were reacted with epoxy biphenyl thus yielding the so‐called Biphenyl OHM capillary column. The modification involved the epoxy ring opening of the 2‐biphenylyl glycidyl ether catalyzed by BF3 and its subsequent reaction with the hydroxyl groups on the OHM precursor surface. The Biphenyl OHM capillary column thus obtained exhibited the typical reversed phase behavior by primarily hydrophobic interactions vis‐à‐vis the homologous series of alkyl benzenes and in addition by π–π interactions toward nitroalkane homologous series via their π‐electron rich nitro groups. This dual retention mechanism was very distinctly observed with a set of PAH solutes in the sense that the k values of the PAH solutes were comparable to those obtained on a more non polar stationary phase, namely the Epoxy OHM C‐16 reported in the preceding article. Other aromatic solutes showed the dual retention mechanism on the Biphenyl OHM capillary including phenols, anilines derivatives, and phenoxy acid herbicides. The Biphenyl OHM capillary exhibited good reproducibility from run‐to‐run, day‐to‐day, and column‐to‐column. 相似文献
1000.
N. A. A. Elkanzi Ashraf A. Aly Ahmed M. Shawky Essmat M. El‐Sheref Nesrin M. Morsy Ahmed A. M. El‐Reedy 《Journal of heterocyclic chemistry》2016,53(6):1941-1944
Reactions of amidines with malononitrile dimer in DMF and catalyzed with piperidine are reported. The reaction occurred via amination process followed by cyclization to give racemic 6‐aminopyrimidine compounds. The reaction mechanism was discussed. The structure of products was elucidated by mass spectrometry, IR and NMR spectra together with elemental analyses. 相似文献