381 research outputs found

    Enzyme activities associated with developing wheat (Triticum aestivum L.) grain amyloplasts

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    Intact amyloplasts from endosperm of developing wheat grains have been isolated by first preparing the protoplasts and then fractionating the lysate of the protoplasts on percoll and ficoll gradients, respectively. Amyloplasts isolated as above were functional and not contaminated by cytosol or by organelles likely to be involved in carbohydrate metabolism. The enzyme distribution studies indicated that ADP-glucose pyrophosphorylase and starch synthase were confined to amyloplasts, whereas invertase, sucrose synthase, UDP-glucose pyrophosphorylase, hexokinase, phosphofructokinase-2 and fructose-2,6-P2ase were absent fro the amyloplast and mainly confined to the cytosol. Triose-P isomerase, glyceraldehyde-3-P dehydrogenase, phosphohexose isomerase, phosphoglucomutase, phosphofructokinase, aldolase, PPi-fructose-6-P-1 phosphotransferase, and fructose-l,6-P2ase, though predominantly cytosolic, were also present in the amyloplast. Based on distribution of enzymes, a probable pathway for starch biosynthesis in amyloplasts of developing wheat grains has been proposed

    Characterization of cytosolic phosphoglucoisomerase from immature wheat (Triticum aestivum L.) endosperm

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    Phosphoglucoisomerase from cytosol of immature wheat endosperm was purified 650-fold by ammonium sulphate fractionation, isopropyl alcohol precipitation, DEAE-cellulose chromatography and gel filtration through Sepharose CL-6B. The enzyme, with a molecular weight of about 130,000, exhibited maximum activity at pH 8.1. It showed typical hyperbolic kinetics with both fructose 6-P and glucose 6-P with Km of 0.18 mM and 0.44mM respectively. On either side of the optimum pH, the enzyme had lower affinity for the substrates. Using glucose 6-P as the substrate, the equilibrium was reached at 27% fructose 6-P and 73% glucose 6-P with an equilibrium constant of 2.7. The ΔF' calculated from the apparent equilibrium constant was +597 cal mol-1. The activation energy calculated from the Arrhenius plot was 5500 cal mol-1. The enzyme was completely inhibited by ribose 5-P, ribulose 5-P and 6-phosphogluconate, with Ki values of 0.17, 0.25 and 0.14 mM respectively. The probable role of the enzyme in starch biosynthesis is discussed

    Toxicity, Spectroscopic Characterization and Electrochemical Behaviour of New Macrocclic Complexes of Lead(II) and Palladium(II) Metals

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    Tetraazamacrocyclie complexes of lead and palladium have been synthesized by the template process using the bis(benzil)ethylenediamine precursor. The tetradentate macrocycle (maL) reacts with PbCl2, PdCl2 and different diamines in a 1:1:1 molar ratio in methanol to give several solid complexes of the types [Pb(maL)(R)Cl2] and [Pd(maL)(R)]Cl2 (where R = 2,6-diaminopyridine or 1,2-phenylenediamine). The macrocycle and its metal complexes have been characterized by elemental analysis, molecular weight determinations, molar conductivity, IR, 1H NMR, 13C NMR, electronic, mass and electrochemical studies. The macrocyclic ligand coordinates through the four azomethine nitrogen atoms which are bridged by benzil moieties. IR spectra suggest that the pyridine nitrogen is not coordinating. The palladium complexes exhibit tetracoordinated square-planar geometry, whereas a hexacoordinated octahedral geometry is suggested for lead complexes. The macrocycle along with its complexes have been screened in vitro against a number of pathogenic fungi and bacteria to assess their growth inhibiting potential

    UV-Vis spectrophotometry and chemometrics as tools for recognition of the biochemical profiles of organic banana peels (Musa sp.) according to the seasonality in southern Brazil

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    Banana (Musa sp.) has received wide interest in popular and scientific medicine because of its rich composition in bioactive metabolites, e.g., phenolic compounds, found in interesting concentrations in its peel. Banana peel is a residue that is under-exploited by the industry. Thus, with the intention to give a destination to this by-product towards health care or cosmetics industries, we evaluated its aqueous extract (AE) as a source of bioactive phenolic compounds, aiming at to apply them in future studies of biological activities. For that, in this study samples of banana peels were chemically profiled throughout the year to identify the best harvest time of those biomasses regarding their phenolic composition. In this sense, we used additional information on the chemical heterogeneity of the samples determined by the seasoning, through a set of analytical and climatic data to elaborate chemometric models, supported by bioinformatics tools. Through PCA and HCA analyzes, it was detected that low temperatures; normally observed in winter; strongly modulate the banana metabolism, leading to increased amounts of phenolic compounds, and improving the antioxidant activity of the banana peel AE. The samples collected during the months of winter showed a similar profile and a relatively high concentration of phenolic compounds with potential for future studies of biological activities.CAPES -Coordenação de Aperfeiçoamento de Pessoal de Nível Superior(407323/2013-9)info:eu-repo/semantics/publishedVersio

    In vitro susceptibility of filamentous fungi from mycotic keratitis to azole drugs

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    Abstract—The Internet-of-Things will require ubiquitous infor-mation sharing between connected things on a global scale, which existing systems do not offer. Most current efforts focus on so-lutions for information dissemination, which induce single points of failure and introduce unnecessary communication delays. To this end we propose the SensibleThings platform, which is a fully distributed open source architecture for Internet-of-Things based applications. This article describes the major problems that Internet-of-Things platforms must address, our technical solution to these problems, and an evaluation thereof. We also present the current progress and a series of demonstrators, which show the wide range of applications enabled by the platform. Finally, we present how the platform will be used in our future research and potential spin off companies. Keywords–overlay;sensors;actuators;internet-of-things. I
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