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301.
Slanina J Glatz Z 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2004,812(1-2):215-229
Lignans are a class of secondary plant metabolites produced by oxidative dimerization of two phenylpropanoid units. They have been found in many plants of Oriental medicine. In consequence of recent knowledge it is held that lignans are responsible for the key pharmacological activities of these plants. This review surveys the chromatographic, electromigration and hyphenated methods so far applied for the separation of lignans in Oriental plants used in phytotherapy as well as for the analyses of these lignans and their metabolites in biological matrices and food samples. In addition, the sample clean-up procedures--solvent extractions and supercritical fluid extractions--are also included. 相似文献
302.
303.
Petra Smrčková Jiří Horský Evžen Šárka Jaroslav Koláček Miloš Netopilík Zuzana Walterová Zdeněk Kruliš Andrey Synytsya Kateřina Hrušková 《Carbohydrate polymers》2013
Wheat B-starch was hydrolysed by α-amylase “Liquozyme supra” from Bacillus licheniformis at 90 °C and pH 7. After 2 h, the dextrose equivalent was 18; according to size exclusion chromatography, however, the hydrolysate contained not only dominant malto-oligosaccharides with the degree of polymerisation (DP) < 10 but also more than 20% of components with DP higher than 40. The product was acetylated to a high degree as verified by FTIR and 1H NMR (degree of substitution DS = 3.1); nevertheless, detailed analysis of the MALDI-TOF mass spectra of the product showed that most of the malto-oligosaccharides molecules contained one or two residual hydroxyls. Size exclusion chromatography confirmed that the acetylated maltodextrin still contained a significant part with DP > 40. This non-uniformity of acetylated maltodextrin, both with respect to DP and to DS, must be taken into account in the development of acetylated-maltodextrin applications such as use as plasticisers or compatibilisers in biodegradable composites. 相似文献
304.
Andrea Kulhánková Lucie Cahlíková Zdeněk Novák Kateřina Macáková Jiří Kuneš Lubomír Opletal 《化学与生物多样性》2013,10(6):1120-1127
The bulbs of Zephyranthes robusta (Amaryllidaceae) have been extensively analyzed for their chemical constituents, resulting in the isolation of 13 alkaloids. The chemical structures of the isolated compounds were elucidated by mass‐spectrometric, and 1D‐ and 2D‐NMR spectroscopic experiments. The complete NMR assignments were achieved for hippeastidine. All isolated alkaloids were evaluated for their erythrocytic acetylcholinesterase and serum butyrylcholinesterase inhibitory activities using the Ellman's method. Significant acetylcholinesterase inhibition activity was exhibited by 8‐O‐demethylmaritidine (IC50(HuAChE) 28.0±0.9 μM ). 相似文献
305.
Frédéric Reymond Christine Vollet Zdeněk Plichta Daniel Horák 《Biotechnology progress》2013,29(2):532-542
This article describes the preparation of tosyl‐activated nonmagnetic poly(2‐hydroxyethyl methacrylate‐co‐glycidyl methacrylate) [P(HEMA‐GMA)] microspheres by dispersion polymerization and tosyl‐activated magnetic poly(2‐hydroxyethyl methacrylate‐co‐ethylene dimethacrylate) [P(HEMA‐EDMA)] microspheres by multistep swelling polymerization method and precipitation of iron oxide inside the pores. These new approaches show that monodisperse microspheres, 2.3 µm, respectively 4.1 µm, in diameter can be produced in high yields avoiding aggregation and with the advantage of being free of aromatic moieties. To demonstrate their potential for diagnostic applications, both types of microparticles have been coated with capture and detection antibodies (DAs), respectively. Immunoassay protocols have then been developed for the dosage of ferritin using an automated affinity platform combining microchannel chips and electrochemical detection. The assay performance using the above magnetic microspheres has been compared with that obtained with commercial tosyl‐activated beads. Finally, the possibility to combine functionalized magnetic and nonmagnetic microspheres has been evaluated in view of amplifying the number of enzymatic labels in the immuno‐complex. At a ferritin concentration of 119.6 ng/mL, a signal‐to‐noise ratio of 150.5 is obtained using 0.2 mg/mL of anti‐ferritin‐coated P(HEMA‐GMA)‐DA microspheres against a value of 158.8 using free DA in solution. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 29: 532–542, 2013 相似文献
306.
A new species of pandalid shrimp Anachlorocurtis occidentalis
sp. n., associated with antipatharian corals, is described and illustrated from the north-eastern Red Sea. This new species is closely related to Anachlorocurtis commensalis Hayashi, 1975, the only other species in the genus, and can be distinguished by the more slender body and appendages; the carapace with 3 large, and one small, subtriangular lobes in the middorsal line; a flattened dorsal outline of the third abdominal segment; the sixth abdominal segment twice as long as fifth one; propodi of the ambulatory pereiopods bearing only a single posterior spinule; and harbouring 3–5 pairs of dorsolateral spines on the telson. A revised generic diagnosis is provided here to accommodate the present new species. The genetic divergence of mitochondrial gene cytochrome c oxidase subunit I (COI) between Anachlorocurtis occidentalis sp. n., and A. commensalis is 15.2–15.4%. Molecular analysis also confirmed a sister position of the genus Anachlorocurtis to Miropandalus. The present records of A. commensalis from Taiwan constitute an extension of the known range of the species. 相似文献
307.
Aleš Skalický Andrea Bohatá Jana Šimková Lance S. Osborne Zdeněk Landa 《Folia microbiologica》2014,59(4):269-276
Eight native isolates of the entomopathogenic fungus Metarhizium anisopliae (Metschnikoff) Sorokin were obtained by monitoring soils cultivated in a conventional manner. These isolates were compared in three areas: (a) conidial germination, (b) radial growth and sporulation and (c) ability of conidia to infect Tenebrio molitor larvae. All bioassays were carried out at constant temperatures of 10, 15, and 20 °C. Conidia of individual isolates demonstrated differences in germination after a 24-h long incubation at all evaluated temperatures. At 20 °C, the germination ranged from 67 to 100 % and at 15 °C from 5.33 to 46.67 %. At 10 °C, no germination was observed after 24 h; nevertheless, it was 8.67–44.67 % after 48 h. In terms of radial growth, the culture diameters and the associated production of spores of all isolates increased with increasing temperature. At 10 °C, sporulation was observed in three isolates while all remaining cultures appeared sterile. Three weeks post-inoculation, conidia of all assessed isolates caused 100 % cumulative mortality of treated larvae of T. molitor at 15 and 20 °C with the exception of isolate 110108 that induced 81.33 % mortality at 15 °C. At 10 °C, larval cumulative mortality ranged from 6.67 to 85.33 % depending on the isolate. Isolates 110108 and 110111 showed significantly slower outset and a much lower rate of infection at all temperatures compared to other tested isolates of M. anisopliae. The bioassays were carried out with the purpose to sort and select indigenous isolates of M. anisopliae useful as biocontrol agents in their original habitat. 相似文献
308.
Zdeněk Žižka 《Folia microbiologica》2014,59(5):363-368
Polarization microscopy has been used to study the internal structures of microbial cells and in terms of the birefringence of these structures and its possible relation to the cell function and composition. Cyanobacteria of the genus Phormidium were found to contain no anisotropic structures, while other microorganisms were found to contain them, albeit to a different extent, size, and number. The flagellate Euglena was found to contain two large anisotropic bodies, whereas the flagellate of the genus Phacus belonging to the same systematic group Euglenales was observed to contain only one large anisotropic body (storage substances—paramylon). On the other hand, green algae of the genus Scenedesmus, whose cells form four-celled coenobia, contained clusters of small anisotropic granules composed also of storage substances (volutin). Minute anisotropic granules (storage substances) in two smaller clusters were found also in diatoms of the genus Navicula, whereas the green alga of the genus Mougeotia was revealed to contain, in addition to minute anisotropic granules (storage substances) occurring in low numbers in the cytoplasm, also a strongly birefringent cell wall (shape birefringence). Cells of the amoeba of the genus Naegleria and heliozoans of the genus Heterophrys were observed to contain only isolated tiny anisotropic granules (storage substances). 相似文献
309.
Svobodová H Ryšavá H Pavlík M Saman D Drašar P Wimmer Z 《Bioorganic & medicinal chemistry》2010,18(23):8194-8203
A series of 10 new pro-juvenoids (juvenogens, insect hormonogenic compounds, pro-drug-like agents) was synthesized using isomeric synthetic juvenoids (insect juvenile hormone analogs) and steroid molecules as patterns modifying parts of the complex hormonogenic molecules. In addition, several new synthons were prepared, which were required by the designed synthetic protocol to achieve the target molecules. These pro-juvenoids were subjected to the topical screening tests and to the drinking assays on the red firebug (Pyrrhocoris apterus), a convenient model laboratory phytophagous insect. Simple and efficient synthetic procedures for the preparation of the target pro-juvenoids and their synthons are presented. Furthermore, the biological activity of the pro-juvenoids in comparison with the activity of their parent juvenoids and that of several commercially available agents is demonstrated. Juvenoids and pro-juvenoids may replace toxic insecticides persistent in the insect pest control because they have no adverse effects on non-target organisms and/or human. 相似文献
310.
Bacteriocin-producing strain of Enterococcus faecium EK 13 with probiotic character and its application in the digestive tract of rabbits 总被引:2,自引:0,他引:2
Andrea Lauková Viola Strompfová Viera Skřivanová Zdeněk Volek Eva Jindřichová Milan Marounek 《Biologia》2006,61(6):779-782
Enterococcus faecium EK 13 is a bacteriocin-enterocin A producing strain with probiotic properties. In this study its colonization, stability
and effect on microflora in rabbits was studied as well as its influence on zootechnical parameters. Fifty rabbits of both
sexes (HYPLUS, 30-day old; after weaning) were divided into control (CG) and experimental (EG) groups. They were fed a standard
diet. Moreover, 25 rabbits in EG were fed daily (for 4 weeks) 15 g (separate doses ∼1.6 g) of lyophilized EK13 strain (rifampicin
resistant variant — rifR; 109 cfu/g) dissolved in drinking water. After cessation of EK13 (rifR) strain application, the rabbits in both groups were fed a standard diet for the next 2 weeks. Sampling was performed in
double on day 0 (at the beginning of experiment), weekly during EK13 (rifR) strain application as well as on week 1 and 2 after cessation of EK13 (rifR) strain application. The counts of EK13 (rifR) strain reached 7.1 ± 2.6 log10 cfu/g after 4 weeks and even on week 2 after its cessation the counts 5.6 ± 2.3 log10 cfu/g were determined. The total counts of enterococci in the rabbits were already increased in EG comparing with CG (p < 0.05); even 2 weeks after EK13 (rifR) strain cessation, their counts in EG were 7.2 ± 2.6 log10 cfu/g (p < 0.001). Enterococci in CG reached at the same time the value 3.7 ± 2.6 log10 cfu/g. The counts of E. coli were significantly reduced in EG during 4 weeks (p < 0.05, p < 0.001). Even 2 weeks after EK13 (rifR) strain cessation significant difference in E. coli counts between CG and EG was detected (p < 0.001). Enterobacteria in EG were significantly reduced (p < 0.001). Average daily gain in EG was 41.0 ± 3.83 in comparison to CG (40.6 ± 3.72); it means almost the same; although
rabbits in EG showed higher feed intake per kg of gain than rabbits in CG. Preliminary results demonstrated that EK13 is a
perspective probiotic candidate for rabbits.
Presented at the Second Probiotic Conference, Košice, 15–19 September 2004, Slovakia. 相似文献