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41.
Synthesis and Crystal Structure of N-Hydroxy-9-(3’,4’-methylene- dioxyphenyl)-1,8-dioxo-1,2,3,4,5,6,7,8,9, 10-decahydroacridine in Aqueous Media 总被引:1,自引:0,他引:1
1 INTRODUCTION Acridine derivatives are described to have many applications, such as biological fluorescent probes[1] as well as anti-tumor[2], anti-bacterial[3], anti-HIV[4] and anti-malarial[5] agents. Because of the importance of acridine derivatives, much work has been done for several decades. Among them the classical synthetic methods involve condensing functionalized anilines and o-halogeno- benzoic acid derivatives as well as several other steps resulting in the desired acridine[… 相似文献
42.
43.
A multi-residue cation-exchange clean up procedure for basic drugs in produce of animal origin 总被引:1,自引:0,他引:1
George Stubbings Jonathan Tarbin Andrew Cooper Matthew Sharman Tim Bigwood Paul Robb 《Analytica chimica acta》2005,547(2):262-268
There is considerable interest in maximising the amount of information obtained from animal product analyses, when screening for the presence of veterinary drug residues. One of the barriers to effective multi-residue analysis to date has been a lack of effective clean up procedures to isolate a wide range of residues from the potential interferents, which may be present in both simple and complex (including processed) foods. A cation-exchange clean up has, therefore, been developed for use with acetonitrile extracts of foods, when analysing for several basic drug groups (sulfonamides, benzimidazoles, levamisole, nitroimidazoles, tranquillisers and fluroquinolones). The clean up procedure has also been shown to be effective using a modified extraction solvent for malachite green and leucomalachite green in fish.Several of the key parameters that influence analyte recovery have been investigated and in an optimised procedure, tissue/biofluid samples containing sulfonamides, benzimidazoles, levamisole, nitroimidazoles, tranquillisers and fluoroquinolones are first extracted with acetonitrile. The extract is then dried with sodium sulfate and acidified with glacial acetic acid before loading onto a Bond Elut, strong cation-exchange (SCX) solid phase extraction (SPE) cartridge. Extracts from fish containing malachite green and leucomalachite green can be cleaned up using the same SCX SPE procedure following extraction with citrate buffer/acetonitrile. Typical recoveries of drugs from low level fortified tissues using the optimised procedure lie in the range 53-104% with the exception of carazolol from pig kidney (31%), malachite green from trout (42-51%) and ciprofloxacin from chicken muscle (44%) and from egg (21%). 相似文献
44.
Thereza Christina Vessoni Penna Eb Chiarini Adalberto Pessoa Junior 《Applied biochemistry and biotechnology》2003,107(1-3):481-491
Transformed cells of Escherichia coli expressing recombinant green fluorescent protein (GFPuv) were subjected to two methods of extraction: (1) freezing/thawing/sonication
(FTS) cycles prior to the three-phase partitioning (TPP) method, or (2) directly to TPP extraction. The amount of GFPuv released
by the FTS plus TPP method varied: 374μg/mL (first cycle), 93–442 μg/mL (second cycle), 32–359 μg/mL (third cycle), 18–115
μg/mL (fourth cycle). The GFPuv yields by the second method (TPP only) were, 23–54 μg/mL for the first extract and 33–91 μg/mL
for the second. The FTS plus TPP method released similar amounts of GFPuv to that extracted by TPP; and provided a better
mixture elution through the hydrophobic interaction column: 13–63 μg/mL for FTS plus TPP methods, and 2.5–13 μg/mL for TPP.
The results showed that although selective permeation is a more laborious methodology, it was more efficient for obtaining
of GFPuv in relation to the direct extraction of the cells for TPP. 相似文献
45.
Keiichi Kimura Masayuki Kaneshige Hideo Tokuhisa Masaaki Yokoyama 《Journal of polymer science. Part A, Polymer chemistry》1993,31(11):2809-2813
Copolymers of bis[4-(N,N-dimethylamino)phenyl]-4-vinylphenylmethanenitrile (vinyl Malachite Green leuconitrile) with methyl methacrylate or ω-methoxyoligo(oxyethylene) methacrylate have been synthesized, aiming at designing one-component-type organic polymers for photoswitchable ion-conducting films. The triphenylmethanenitrile copolymers with ω-methoxyoligo(oxyethylene) methacrylate were found to undergo ionic-conductivity switching by turning on and off UV light at ambient temperature, owing to their low glass transition temperature. © 1993 John Wiley & Sons, Inc. 相似文献
46.
Synthesis and properties of chiral ammonium-based ionic liquids 总被引:1,自引:0,他引:1
New chiral ammonium-based ionic liquids containing the (1R,2S,5R)-(-)-menthyl group can be easily and efficiently prepared under ambient conditions. The preparation and characterization of trialkyl[(1R,2S,5R)-(-)-menthoxymethyl]ammonium salts is reported. The salts have been demonstrated to be air- and moisture-stable under ambient conditions and can be readily used in a variety of standard experimental procedures. The single-crystal X-ray structure of butyldimethyl[(1R,2S,5R)-(-)-menthoxymethyl]ammonium chloride has been determined. The chiral, room-temperature ionic liquids have been characterized by physical properties such as specific rotation, density, viscosity, thermal degradation, and glass transition temperature. Trialkyl[(1R,2S,5R)-(-)-menthoxymethyl]ammonium chloride prototype ionic liquids have also been found to exhibit strong antimicrobial and high antielectrostatic activities. 相似文献
47.
《Chemphyschem》2003,4(6):588-594
The reorientational dynamics of the ionic liquid 1butyl‐3‐methylimidazolium hexafluorophosphate ([BMIM]PF6) were studied over a wide range of temperatures by measurement of 13C spin–lattice relaxation rates and NOE factors. The reorientational dynamics were evaluated by performing fits to the experimental relaxation data. Thus, the overall reorientational motion was described by a Cole–Davidson spectral density with a Vogel–Fulcher–Tammann temperature dependence of the correlation times. The reorientational motion of the butyl chain was modelled by a combination of the latter model for the overall motion with a Bloembergen–Purcell–Pound spectral density and an Arrhenius temperature dependence for the internal motion. Except for C2 in the aromatic ring, an additional reduction of the spectral density by the Lipari–Szabo model had to be employed. This reduction is a consequence of fast molecular motions before the rotational diffusion process becomes effective. The C2 atom did not exhibit this reduction, because the librational motion of the corresponding C2? H vector is severely hindered due to hydrogen bonding with the hexafluorophosphate anion. The observed dynamic features of the [BMIM]+ cation confirm quantum‐chemical structures obtained in a former study. 相似文献
48.
49.
Xiao Hua WANG Han Zhi WANG Hui LIU Yuan KOU 《中国化学快报》2006,17(12):1531-1533
Recent years, crown ethers have been used in many fields, including phase transfer catalysis, chromatography stationary phase, ionselective electrode, and concentration of metal ions, etc1.. However, the toxicity of free crown ethers makes them unsuitable for industrial use2. Introduction of a crown ether as a functional group to functionalized ionic liquids has been reported3. These functionalized ionic liquids will combine the excellent properties of crown ether and ionic liquids without los… 相似文献
50.
Chih-Hsin Tsai 《Talanta》2007,72(2):368-372
A capillary electrophoresis Raman spectroscopy (CE-RS) method based on the stacking and sweeping modes are described. A non-fluorescent compound (malachite green, MG; crystal violet, CV) and a doubled Nd:YAG laser (532 nm, 300 mW) were selected as the model compound and light source, respectively. In order to carry out a quantitative and analysis of MG, a monochromator was used to collect the specific Raman line at 1616 cm−1 (the N-φ and C-C stretching, corresponding to 582 nm when the wavelength of the exciting source is 532 nm). The limit of detection (LOD) for MG was 1.6 × 10−5 and 1.1 × 10−5 M, respectively, based on the CZE and MEKC modes. This could be improved to 3.4 × 10−7 and 5.3 × 10−9 M, respectively, when the stacking and sweeping modes were applied. The method was also extended to the determination of MG in an actual sample. 相似文献