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41.
42.
Ma. Carmen García-González Eduardo Hernández-Vázquez Fabio A. Vengochea-Gómez Luis D. Miranda 《Tetrahedron letters》2018,59(9):848-852
1,4- or 1,5-migration of a double bond of dehydroalanines under palladium catalysis is reported. The process occurred with several highly-substituted dehydroalanines under mild typical Heck reaction conditions. Although this was one of the first reports of a palladium-catalyzed 1,5-olefin migration, the outcome of the reaction was susceptible to the starting material. Mechanistically, the process involved a five- (1,4-migration) or six-membered ring (1,5-migration) organopalladium intermediate, which cleaved a C–N bond in an β-amino elimination process. 相似文献
43.
44.
A novel, fast and simple liquid chromatographic method was developed and validated for the simultaneous determination of rosiglitazone and metformin in human plasma. The analysis was performed on a phenyl column (250 mm × 4.6 mm i.d., 5 μm) using a gradient method starting with mobile phase composed of acetonitrile:5 mM acetate buffer pH 5.5 (75:25, v/v). The flow rate was 1 mL min−1. UV detection was performed at 245 nm and verapamil was used as internal standard. The total run time was less than 10 min. Sample preparation included a simple protein precipitation step with acetonitrile. Validation experiments were performed to demonstrate stability, specificity, sensitivity, linearity, accuracy, precision and robustness. The limit of quantification was 100 ng mL−1 for rosiglitazone and 250 ng mL−1 for metformin. The extraction recoveries were 100.02-105.0% for rosiglitazone and 105.64-103.88% for metformin. The method was applied with success to plasma samples obtained from diabetic patients undergoing treatment with rosiglitazone and metformin. 相似文献
45.
《Analytical letters》2012,45(3):315-321
Abstract A high-performance liquid chromatography assay was developed for the purpose of examining xanthine, hypoxanthine, uridine, thymidine, allopurinol, and oxypurinol in serum of patients with advanced carcinoma treated with methorexate and 5-fluorouracil. After the addition of an internal standard, serum samples were extracted of purines and pyrimidines with trichloroacetic acid and neutralized with tert-amine. Aliquots of the extracted serum were injected onto a C18 reverse-phase column and purines and pyrimidines were eluted with a gradient of MeOH/H2O and KH2PO4 solutions. Absorbance was detected with a variable-wavelength UV spectrophotometer at 254 nm and 280 nm. This assay can be readily applied to quantitate baseline and treatment-induced variations in serum purine and pyrimidine levels which may correlate with clinical response and/or toxicity in patients with cancer. 相似文献
46.
Daoyong Zhu Zhiwei Jiao Yonggui Robin Chi Tho P. Gonalves Kuo‐Wei Huang Jianrong Steve Zhou 《Angewandte Chemie (International ed. in English)》2020,59(13):5341-5345
Substituted cyclohexylamines are becoming increasingly important in drug discovery. Asymmetric Heck insertion/amination of nonconjugated cyclodienes proceeds to give 5‐aryl cyclohexenylamines with good enantioselectivity and exclusive trans configurations. Primary and secondary anilines, indoline, and benzylamines are suitable amines. The weakly donating diphosphite Kelliphite forms a deep unsymmetrical pocket, which is essential for stereoselective anti attack of amines. 相似文献
47.
Evaluation of a sensitive HPLC method for the determination of Malondialdehyde, and application of the method to different biological materials 总被引:1,自引:0,他引:1
G. A. Khoschsorur B. M. Winklhofer-Roob H. Rabl Th. Auer Z. Peng R. J. Schaur 《Chromatographia》2000,52(3-4):181-184
Summary Reactive oxygen species (ROS), important mediators of cell and tissue injury during inflammation, are produced by several
types of inflammatory cells. The formation of ROS can be monitored by detection of lipid peroxidation products. The extremely
broad spectrum of biological effects of aldehydic lipid peroxidation products has necessitated the development of a technique
that enables the sensitive routine quantitation of aldehydes formed in biological materials. Malondialdehyde (MDA) is a by-product
of enzymatic eicosanoid formation and an end-product of nonenzymatic peroxidation of polyunsaturated fatty acids with three
or more bisallylic double bonds. The determination of the thiobarbituric acid derivative of MDA (TBA-MDA) is a widely used
method for estimating overall lipid peroxidation. We describe a rapid, isocratic, simple, and sensitive high-performance liquid
chromatographic (HPLC) method with spectrofluorimetric detection for measurement of MDA-TBA in human biological samples such
as plasma, urine, wound secretions, amniotic fluid, sputum and tissue samples. By use of this method, picomole quantities
of MDA can be readily and specifically detected in different biological materials. Coefficients of variation of repeated MDA-TBA
assays were 4.4% within run and 6.9% from run to run. Reference values are given for a variety of human body fluids and for
rat tissues. 相似文献
48.
Solid-phase microextraction coupled with microcolumn liquid chromatography for the analysis of amitriptyline in human urine 总被引:1,自引:0,他引:1
Summary Solid-phase microextraction (SPME) is a solvent-free sample-preparation technique that enables isolation and pre-concentration
of analytes from a sample on a thin film coating a fused-silica fiber. In this study SPME coupled with microcolumn liquid
chromatography (micro LC) has been used for the determination of four tricyclic antidepressants (amitriptyline, imipramine,
nortriptyline, and desipramine) in human urine. SPME conditions which affect extraction efficiency were optimized, and under
the optimum conditions the system was a few hundred times more sensitive than direct LC analysis without SPME. For amitriptyline
the detection limit was 3 ng mL−1 and the calibration curve was linear in the range of 5–500 ng mL−1. The SPME-micro LC method has been applied to the analysis of amitriptyline in patient’s urine. 相似文献
49.
Anthropogenic emissions, such as those from combustion of fossil fuel, waste incineration and industrial use, contribute to higher levels of metal pollutants, including Cd, Pb and Sb, in the urban environment. These widespread and persistent environmental pollutants have the potential for developmental and reproductive toxicity. Health risks are particularly associated with exposure in utero and the early years of life, since the developing organism is at greater risk from permanent damage, and both absorption and retention can be considerably greater in infants than adults. In order to assess risk to humans, the information on environmental levels of pollutants (environmental monitoring) should be integrated with information on biomarkers of exposure, effect or susceptibility in biological fluids or tissues (biological monitoring). The analysis of tissue from the target organ obtained at autopsy provides a direct record of the accumulation of toxins and allows temporal and geographical trends to be studied. Few literature reports on tissue content of potentially toxic elements include data on newborns and young children since collections of autopsy samples in this age range are rare. Existing data are sometime questionable, because of inadequate sensitivity of the analytical techniques, insufficient control of contamination and lack of validation. Our recent work aimed to establish reliable reference values for the content of Cd, Pb and Sb in the liver of pediatric subjects. 相似文献
50.
《印度化学会志》2021,98(6):100082
This study has investigated docking-based 2D- and 3D-quantitative structure-activity relationships (QSARs) for a range of 53 hydroxybenzamide analogues as anti- Human adenoviruses (HAdVs). The best 3D-QSAR (Schrodinger, LLC, NY, 2020) and 2D-QSAR models were obtained for the training set and were found to be statistically significant, with cross-validated coefficients (q2) of 0.6775 and 0.7875, and coefficients of determination (r2) of 0.8106 and 0.8122, respectively. Our in-silico docking and virtual screening studies revealed significant higher binding affinity of dataset molecule 34 (-141.444 kcal/mol) and hit ZINC01088642 (-114.357 kcal/mol) with 4PIE protein than the standard drugs. In in-silico ADME/toxicity studies, molecule 34 and proposed hit ZINC01088642 were found safe with good intestinal absorption, aqueous solubility, medium blood–brain barrier (BBB), no eye corrosion, no skin irritancy, and non-mutagenic profiles. Molecular dynamics analysis showed good stability of complex, hit ZINC01088642 with protein, 4PIE over the simulation period of 20 ns. We believe that further experimental, as well as in-vitro investigation, will shed more lights on the identification of ZINC01088642 as a potential human adenovirus agent. 相似文献