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Evaggelia Tsandi 《Tetrahedron》2009,65(7):1444-1135
Sulfonamides of the non-natural amino acid homoproline and the dipeptide Pro-Phe were synthesised and evaluated for their catalytic activity in Michael and aldol reactions. Sulfonamides of homoproline outperform proline and Pro-Phe in the Michael reaction, whereas sulfonamides of Pro-Phe lead to better results in the aldol reaction. The results of the present study show that the conversion of the carboxylic group of either homoproline or dipeptide Pro-Phe to the bioisosteric acyl sulfonamide group lead to improved organocatalysts. 相似文献
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Eleni Kalogria Athanasia Varvaresou Spyridon Papageorgiou Evaggelia Protopapa Ioannis Tsaknis Alexios Matikas Irene Panderi 《Chromatographia》2014,77(19-20):1275-1281
This article describes the development and validation of a selective high-performance liquid chromatography method that allows, after liquid–liquid extraction and pre-column derivatization reaction with quercetin, the quantification of aluminium chlorohydrate in antiperspirant creams. Chromatographic separation was achieved on an XTerra MS C18 analytical column (150 × 3.0 mm i.d., particle size 5 μm) using a mobile phase of acetonitrile:water (15:85, v/v) containing 0.08 % trifluoroacetic acid at a flow rate of 0.30 mL min?1. Ultraviolet spectrophotometric detection at 415 nm was used. The assay was linear over a concentration range of 3.7–30.6 μg mL?1 for aluminium with a limit of quantitation of 3.74 μg mL?1. Quality control samples (4.4, 17.1 and 30.6 μg mL?1) in five replicates from five different runs of analysis demonstrated intra-assay precision (% coefficient of variation <3.8 %), inter-assay precision (% coefficient of variation <5.4 %) and an overall accuracy (% recovery) between 96 and 101 %. The method was used to quantify aluminium in antiperspirant creams containing 11.0, 13.0 and 16.0 % (w/w) aluminium chlorohydrate, respectively. 相似文献
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Samanidou V Evaggelopoulou E Trötzmüller M Guo X Lankmayr E 《Journal of chromatography. A》2008,1203(2):115-123
A sensitive and selective confirmatory analytical method for the multi-residue determination of seven quinolones (ciprofloxacin, enrofloxacin, sarafloxacin, danofloxacin, oxolinic acid, nalidixic acid and flumequine) in gilthead seabream (Sparus aurata) was developed. The sample pre-treatment involves extraction with 0.1M NaOH and purification by solid-phase extraction (SPE) on Waters Oasis HLB cartridges followed by the determination of all compounds in a single LC-electrospray ionization MS/MS run. Separation was achieved on a Perfectsil ODS-2, 5mum, 250mmx4mm, analytical column (MZ Analysentechnik) by gradient elution using a mixture of 0.2% (v/v) formic acid, methanol and acetonitrile within 30min. Multiple reaction monitoring (MRM) was used for selective detection of each quinolone. Accuracy was evaluated through recovery studies at three different fortification levels. The mean recoveries are between 90 and 132% for the selected levels with RSD values lower than 20%. The method presents satisfactory results for linearity, precision and limits of quantification. The latter are much lower than the maximum residue limits (MRLs) established by the European Union for quinolones in fish tissues (6-8mug/kg). 相似文献
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The accelerated growth of aquaculture has resulted in a series of harmful effects to human health. The widespread and unrestricted use of antibiotics in this industry, to prevent bacterial infections, leads to remaining amounts in the aquatic environment. This has resulted in the emergence of antibiotic-resistant bacteria in aquaculture environments, in the increase in antibiotic resistance in fish pathogens as well as in the transfer of these resistance determinants to human pathogens. Moreover, the use of large amounts of antibiotics may lead to the presence of residual antibiotics in fish tissue and fish products. Fluoroquinolones, tetracyclines, penicillins, sulphonamides and other antibiotics, exhibiting activity against both Gram-positive and Gram-negative bacteria, are widely used for the treatment and prevention of diseases in fish. An extended and comprehensive review on the recent analytical methodologies concerning antibiotic residues in fish reported in the literature is provided in the present article. Emphasis is given on sample preparation regarding isolation and purification, chromatographic conditions and method validation according to legislation. Results of published assays are comparatively presented and criticised. 相似文献
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Litos IK Emmanouilidou E Glynou KM Laios E Ioannou PC Christopoulos TK Kampa M Castanas E Gravanis A 《Analytical and bioanalytical chemistry》2007,389(6):1849-1857
In recent years an increasing amount of interest has been directed at the study and routine testing of polymorphisms responsible
for variations in drug metabolism. Most of the current methods involve either time-consuming electrophoresis steps or specialized
and expensive equipment. In this context, we have developed a rapid, simple and robust method for genotyping of CYP2D6*3,
CYP2D6*4, CYP2C19*2, CYP2C19*3 and TPMT*2 single nucleotide polymorphisms (SNP). Genomic DNA is isolated from whole blood
and the segments that span the SNP of interest are amplified by PCR. The products are subjected directly (without purification)
to two primer extension (PEXT) reactions (three cycles each) using normal and mutant primers in the presence of biotin-dUTP.
The PEXT primers contain a (dA)30 segment at the 5′ end. The PEXT products are detected visually by a dry-reagent dipstick-type assay in which the biotinylated
extension products are captured from immobilized streptavidin on the test zone of the strip and detected by hybridization
with oligo(dT)-functionalized gold nanoparticles. Patient samples (76 variants in total) were genotyped and the results were
fully concordant with those obtained by direct DNA sequencing. 相似文献
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Manolis A. Fousteris Anna I. Koutsourea Evaggelia S. Arsenou Sotiris S. Nikolaropoulos Ioannis K. Stamos L. Leondiadis 《Journal of heterocyclic chemistry》2004,41(3):349-353
The synthesis of seven pyrrolo[2,3‐a]carbazoles derivatives using Fischer indole cyclization conditions is described. Polyphosphoric acid trimethylsilyl ester was used as a mild catalyst for the cyclization step of intermediate arylhydrazones which were prepared from ethyl 7‐oxo‐4,5,6,7‐tetrahydroindole‐2‐carboxylate and used as such without further purification. In all cases a mixture of two products was obtained, the dihydro and the corresponding dehydrogenated one. The completion of the dehydrogenation was achieved by treatment of this resultant mixture with dichlorodicyanoquinone. 相似文献
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C60 reacts thermally with 1,3-dipoles, formed in situ, from sulfide-bearing imines of glycine esters, and affords dihydro-pyrrolo [60]fullerene derivatives containing a vinylic sulfide group, which were isolated in good yields, and characterized with 1H and 13C NMR, FTIR, UV-vis spectroscopies, and with FAB, ESI mass spectrometries. The new derivatives contain a sulfide, an imine, and an ester functionality for further chemical transformations. Mechanistic considerations with regard to the loss of a mercaptan molecule in the course of the cycloaddition are deployed. 相似文献