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41.
Boris Pejin Ana Ciric Mladen Horvatovic Tamara Jurca Jasmina Glamoclija Milos Nikolic 《Natural product research》2016,30(16):1839-1843
The antimicrobial activity of five crude extracts of the freshwater bryozoan Pectinatella magnifica (Leidy, 1851) was evaluated in vitro for the first time. P. magnifica acetone extract exhibited the highest antibacterial activity (minimum inhibitory concentrations (MIC) 0.004–0.350 mg/mL and MBC 0.007–0.500 mg/mL), while its methanol extract showed the most promising antifungal activity (MIC 0.03–0.12 mg/mL and MFC 0.06–0.25 mg/mL). Furthermore, at a concentration of 0.25 MIC, the methanol extract reduced biofilm formation of the bacterial strain Pseudomonas aeruginosa PAO1 in a considerable extent (59.14%). FTIR spectra of the most active extracts indicate the presence of carbonyl compounds, long-chain alcohols and/or sterols. According to the experimental data obtained, P. magnifica methanol extract may be considered as a good resource of novel natural products with potent antibiofilm activity against the bacterium well known for its resistance. 相似文献
42.
Nikodinovic J Dinges JM Bergmeier SC McMills MC Wright DL Priestley ND 《Organic letters》2006,8(3):443-445
[reaction: see text]. An efficient resolution of methyl nonactate is reported by biotransformation in shake flask cultures of Rhodococcus erythropolis. The equilibrium of the reaction redox system can be manipulated by switching from aerobic to anaerobic growth, thereby generating both enantiomers of the target in excellent yield and enantiomeric purity. 相似文献
43.
Jasmina Simonić Jelena Vukojević Mirjana Stajić Jasmina Glamočlija 《Applied biochemistry and biotechnology》2010,162(2):408-415
Comparison of the potential for laccase and Mn-oxidizing peroxidases synthesis by ten strains of Ganoderma lucidum, originating from different worldwide areas, during solid-state fermentation of selected plant raw materials was the aim
of this study. The great intraspecific variability in the production of analyzed enzymes as well as the dependence of the
enzyme activity on plant raw materials were reported. The strain HAI 957 was the best laccase producer in the presence of
corn stem, as a unique carbon source (129.46 U/L). The highest level of Mn-dependent peroxidase activity was noted after wheat
straw fermentation by G. lucidum HAI 246 (78.64 U/L), while the maximal versatile peroxidase production (59.72 U/L) was observed in strain HAI 957 in the
medium with oak sawdust. 相似文献
44.
Kmak Kelly N. Shaughnessy Dawn A. Vujic Jasmina 《Journal of Radioanalytical and Nuclear Chemistry》2020,323(2):931-945
Thorium-230 has many research applications, but there is not a commercial source of this isotope. However, since 230Th is part of the 238U decay chain, it can be separated from naturally occurring uranium. In this work, a novel procedure was developed to separate thorium from uranium ore, consisting of leaching, liquid–liquid extraction, precipitations and ion exchange chromatography. The final product was 91.32?±?0.77 mg of thorium with a purity of 99.5?±?1.2 wt%. Of that, 7.65?±?0.10 mg was 230Th and the remainder 232Th. The total yield of 230Th was 71.1?±?5.4%. Ways to improve the yield by further processing the back-extraction solution are suggested.
相似文献45.
Popa C. Bratu A. M. Matei C. Cernat R. Popescu A. Dumitras D. C. 《Laser Physics》2011,21(7):1336-1342
The hypothesis that blood, urine and other body fluids and tissues can be sampled and analyzed to produce clinical information
for disease diagnosis or therapy monitoring is the basis of modern clinical diagnosis and medical practice. The analysis of
breath air has major advantages because it is a non-invasive method, represents minimal risk to personnel collecting the samples
and can be often sampled. Breath air samples from the human subjects were collected using aluminized bags from QuinTron and
analyzed using the laser photoacoustic spectroscopy (LPAS) technique. LPAS is used to detect traces of ethylene in breath
air resulting from lipid peroxidation in lung epithelium following the radiotherapy and also traces of ammonia from patients
subjected to hemodialysis for treatment of renal failure. In the case of patients affected by cancer and treated by external
radiotherapy, all measurements were done at 10P(14) CO2 laser line, where the ethylene absorption coefficient has the largest value (30.4 cm−1 atm−1), whereas for patients affected by renal failure and treated by standard dialysis, all measurements were performed at 9R(30)
CO2 laser line, where the ammonia absorption coefficient has the maximum value of 57 cm−1 atm−1. The levels of ethylene and ammonia in exhaled air, from patients with cancer and renal failure, respectively, were measured
and compared with breath air contents from healthy humans. Human gas biomarkers were measured at sub-ppb (parts per billion)
concentration sensitivities. It has been demonstrated that LPAS technique will play an important role in the future of exhaled
breath air analysis. The key attributes of this technique are sensitivity, selectivity, fast and real time response, as well
as its simplicity. 相似文献
46.
The title compound was obtained by reduction of diethyl (ferrocenylmethyl)malonate with lithium aluminium hydride in diethyl ether. The structure of this novel ferrocene derivative was assigned by means of elemental analysis, IR, [1H]NMR, and [13C]NMR spectroscopy. The structure was also confirmed by a single crystal X-ray study. The compound crystallizes in monoclinic P21/a space group with unit cell dimensions: a = 9.7360(6), b = 27.040(5), c = 14.767(3) Å, = 103.835(6)°, V = 3774.8(11) Å3, Z = 12. The asymmetric unit contains three crystallographically independent molecules. In the ferrocenyl moieties, the Fe–C bond distance values are in the range 2.006(5)—2.051(3) Å and C–C distances in the range 1.366(7)–1.425(4) Å. The cyclopentadienyl rings in each of the molecules are mutually twisted by about 13° from the eclipsed conformation. The hydroxyl groups are involved in the intermolecular O–H...O hydrogen bond formation with O-O distances in the range 2.686(3)–2.801(4) Å forming infinite two-dimensional network in a [0 0 1] plane. The crystal structure is additionally stabilized by C–H-O weak intermolecular hydrogen bonds. 相似文献
47.
Csaba-Pal Racz Szabolcs Santa Maria Tomoaia-Cotisel Gheorghe Borodi Irina Kacso Adrian Pirnau Ioan Bratu 《Journal of inclusion phenomena and macrocyclic chemistry》2013,76(1-2):193-199
The inclusion of α-lipoic acid (LA) in β-cyclodextrin (β-CD) by increasing the aqueous solubility and photostability can enhance its medicinal use in the oral administration. Different preparation methods were employed to obtain an α-lipoic acid-β-cyclodextrin (LA-β-CD) inclusion complex and to determine the physical–chemical characteristics and the interactions present in this compound. The formation of the solid inclusion compound was confirmed by X-ray powder diffraction, differential scanning calorimetry (DSC) and infrared spectroscopy (FTIR). FTIR and DSC data confirm the new obtained compound. The crystalline structure of this compound belongs to the monoclinic system with four molecules in the unit cell. 1H NMR spectroscopic method was employed to study the inclusion process in aqueous solution. Job plots derived from the 1H NMR spectral data demonstrated an 1:1 stoichiometry of the inclusion complex in liquid state. 2D NMR data suggest the orientation of LA with the carboxyl group near to narrower rim of the β-CD. 相似文献
48.
Djordjevic Jasmina Konjik Sanja Mitrović Darko Novak Andrej 《Journal of Optimization Theory and Applications》2021,190(1):316-338
Journal of Optimization Theory and Applications - We consider exact and averaged control problem for a system of quasilinear ODEs and SDEs with a nonnegative definite symmetric matrix of the... 相似文献
49.
Bogeski I Gulaboski R Kappl R Mirceski V Stefova M Petreska J Hoth M 《Journal of the American Chemical Society》2011,133(24):9293-9303
Coenzyme Q10 (CoQ10) is one of the essential components of the mitochondrial electron-transport chain (ETC) with the primary function to transfer electrons along and protons across the inner mitochondrial membrane (IMM). The concomitant proton gradient across the IMM is essential for the process of oxidative phosphorylation and consequently ATP production. Cytochrome P450 (CYP450) monoxygenase enzymes are known to induce structural changes in a variety of compounds and are expressed in the IMM. However, it is unknown if CYP450 interacts with CoQ10 and how such an interaction would affect mitochondrial function. Using voltammetry, UV-vis spectrometry, electron paramagnetic resonance (EPR), nuclear magnetic resonance (NMR), fluorescence microscopy and high performance liquid chromatography-mass spectrometry (HPLC-MS), we show that both CoQ10 and its analogue CoQ1, when exposed to CYP450 or alkaline media, undergo structural changes through a complex reaction pathway and form quinone structures with distinct properties. Hereby, one or both methoxy groups at positions 2 and 3 on the quinone ring are replaced by hydroxyl groups in a time-dependent manner. In comparison with the native forms, the electrochemically reduced forms of the new hydroxylated CoQs have higher antioxidative potential and are also now able to bind and transport Ca(2+) across artificial biomimetic membranes. Our results open new perspectives on the physiological importance of CoQ10 and its analogues, not only as electron and proton transporters, but also as potential regulators of mitochondrial Ca(2+) and redox homeostasis. 相似文献
50.
An experimental design method was used for fast, simple, and accurate high-performance-pressure liquid chromatograpy (HPLC) determination of losartan and hydrochlorothiazide in combined dosage forms. This method avoids the disadvantages of the traditional analytical approach, which is time-consuming, involves a large number of runs, and does not allow the determination of multiple interacting parameters. On the basis of preliminary experiments, three independent variables (methanol content, pH value of the mobile phase, and flow rate) were selected as input, and as dependent variables, five responses (retention time of hydrochlorothiazide, retention time of losartan, asymmetry of hydrochlorothiazide peak, asymmetry of losartan peak, and resolution) were chosen. A full 23 factorial design was used to determine which factors had an effect on the studied response. Afterwards, experimental design was used to optimize these influencing parameters in the previously selected experimental domain. After optimizing the experimental conditions, a separation was conducted on a Zorbax C8 (150 mm × 4.6 mm, 5 μm particle size) column with a mobile phase consisting of methanol–acetonitrile–acetate buffer 45:20:35 v/v/v, pH 4.8 with flow rate of 0.82 mL min?1 and column temperature of 25 °C. The developed method was successfully applied to simultaneous separation of these active drug compounds in their commercial pharmaceutical dosage forms. 相似文献