Flavine und Zimtsäurederivat im Zusammenhang mit der lichtinduzierten Blattöffnung bei Albizia julibrissin

Flavins and Chinamoyl Derivatives in Relation to the Light-induced Leaf Opening in Albizia julibrissin In search of blue-light photoreceptors for light-induced leaf opening we isolated from the aqueous extract of Albizia julibrissin Durazz. two flavins by adsorption on XAD-4 and separation with HPLC. One sample was identified as riboflavin 1a. In the hydrolysate of the second flavin fraction we found another dimethylisoalloxazine with a C₅-side chain. Furthermore we isolated the cinnamoyl derivatives 3-O-(4-hydroxy-trans-cinnamoyl) quinic acid 2 and 3-O-(3,4-dihydroxy-trans-cinnamoyl)-4-O-malonyl-quinic acid 3 which formed charge transfer complexes with the flavins in the XAD-fraction. As a model complex we examined the absorption behaviour of the complex between riboflavin and chlorogenic acid. Using the association constant, we calculated the absorption spectrum and could show that a complex between a flavin and a phenolic compound is a possible blue-light photoreceptor for the light-induced leaf opening in Albizia julibrissin.     

Determination of Glyphosate and Its Metabolite AMPA (Aminomethylphosphonic Acid) in Cereals After Derivatization by Isotope Dilution and UPLC-MS/MS”

A straightforward analytical method has been developed for the determination of glyphosate and aminomethylphosphonic acid (AMPA), its major metabolite in cereals. This method entails a rapid extraction and derivatization with 9-fluorenylmethyl chloroformate followed by separation with a conventional reversed-phase rapid chromatography used in daily routine analysis and detection by electrospray ionization tandem mass spectrometry. To overcome matrix effects and compensate for any analyte losses during sample treatment, an isotopic dilution approach was used. Since 2010, the monitoring of cereals for the widely used herbicide glyphosate is obligatory to all European Union (EU)-member states, laid down in Commission Regulation (EC) No. 1213/2008. Hence, there is definitively a need for a reliable and easy-to-handle analytical method for monitoring of this compound. The proposed method can be run without having to make time-consuming changes on the equipment used for daily routine analysis. The analytical performance of the method was evaluated according to SANCO/10684/2009 criteria and demonstrated that this method is rugged and cost-effective, therefore suitable for monitoring purposes as well as legislative enforcements within the EU. The apparent recoveries of both analytes were between 97% and 113% with relative standard deviations less than 20%. The limits of quantification of glyphosate and AMPA were 0.02 mg/kg in cereal matrices. Finally, the accuracy of the method was assessed by analyzing a proficiency test material which was available from a previous round (EUPT-C4).     

Cloning of the bile salt hydrolase (bsh) gene from Enterococcus faecium FAIR-E 345 and chromosomal location of bsh genes in food enterococci

Enterococcus faecium strain FAIR-E 345 isolated from food was shown to possess bile salt hydrolase (Bsh) activity in a plate screening assay and by high-performance liquid chromatography analysis. The bsh gene was cloned and sequenced. DNA sequence analysis revealed that it encoded a protein of 324 amino acids, with pI 4.877. A bsh gene probe was prepared from the cloned bsh gene and was used for probing plasmid and total genomic DNA of Bsh-positive enterococci isolated from food to determine the genomic location of their bsh genes. This probe was able to detect the bsh gene among total genomic DNA preparations but not from plasmid preparations of 10 plasmid-bearing Enterococcus strains. However, the probe could detect the bsh gene from total genomic DNA preparations of 12 Enterococcus strains that did not contain detectable plasmid DNA. In no cases did the probe hybridize with plasmid DNA preparations, suggesting that the bsh gene among enterococci is probably generally chromosomally encoded. This presumptive chromosomal location of bsh genes among food enterococci suggests that transfer of this trait by conjugative plasmids is unlikely.     

Influence of Methanol on Prion Reduction during High Temperature and High Pressure Oleochemical Processes

Prion‐reduction in standard biodiesel processes is caused by acidic and alkaline conditions. In the alternative RepCat biodiesel process, efficient prion‐reduction can be achieved by high‐temperature/pressure. However, a possible increase in thermostability of prions in the presence of methanol during these conditions has not previously been investigated, and is verified in this work. Samples are spiked with prions, treated with methanol, and incubated at 220 °C at 80 bar for 30 min. No traces of protease‐resistant prion protein (as proxy for prions) are detected in tallow or glycerine (as the final by‐product) after treatment. Serial dilutions of spiked prions show at least 6 log₁₀ prion reduction. More importantly, similar effects are detected using milder conditions of 200 °C at 70 bar for 15 min, representing the worst‐case conditions of the process. In conclusion, this study shows that methanol does not increase the thermostability of prions and the RepCat process can efficiently eliminate prions and is therefore safe for the usage of category 1 tallow. Practical Applications: The study further supports the applicability of RepCat process in reducing prion‐contamination in the presence of methanol. Furthermore, the conditions leads to a considerable reduction of prions in glycerine obtained as by‐product.     

Oxide ceramic fibers via dry spinning process—From lab to fab

Oxide fibers preparation and manufacturing capabilities at Fraunhofer-Center HTL are introduced, showing the development and preparation of oxide ceramic fibers from lab scale to pilot scale up to near production scale. As a specific example, the development of an aluminosilicate fiber with mullite composition is discussed in more detail. Fiber development started from nonaqueous sol-gel precursors in the early lab scale. With increasing fiber spinning volume, precursors were switched to water-soluble systems. Transformation from green fiber to ceramic fiber was monitored by thermogravimetric and differential thermal analysis, X-ray diffraction, and scanning electron microscopy. The evolution of ceramic phases, microstructure formation, and the effects on tensile strength and Young's modulus were investigated. Weibull statistics and fracture analysis helped to understand the results. Next step will be the transition from large lab scale to pilot scale, demonstrating manufacturing capability.     

L?slichkeit und gel-elektrophoretische Muster hitzedenaturierter Proteine, auch von st?rkehaltigen Proben, nach Einwirkung von Na-dodecylsulfat (SDS)

Zusammenfassung Das Lösungsvermögen des Anionendetergents Na-dodecylsulfat (SDS) in Gegenwart disulfidbrückenspaltender Reagentien auf native und auf hitzedenaturierte Proteine wird an Fleisch-und Kartoffelproteinen mit Hilfe elektrophoretischer Methoden untersucht. Die zur Resolubilisierung notwendige Menge an SDS und die erforderliche Incubationszeit werden für die verschiedenen Proben ermittelt. Die Proteine des Skeletmuskels von Rind, Schwein, Huhn und Pute einerseits und die Proteine der europäischen Kartoffelsorten und der südamerikanischen Primitivkultivare andererseits zeigen in der SDS-PAGE ein sehr ähnliches Bandenmuster, das speziesdifferenzierend kaum ausgewertet werden kann, aber ein gutes Charakteristikum für Muskel-bzw. Kartoffelproteine ist.

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Solubility and electrophoretic patterns of heat-denaturated proteins (including samples containing starch) after treatment with SDS (sodiumdodecylsulfat)

Summary The ability of the anionic detergent SDS (sodium-dodecylsulfate) to solubilize native and heat-denaturated proteins of meat and potatoes in presence of disulphide reducing agents was checked by electrophoretic methods. Skeletal muscle proteins of beef, pork, chicken and turkey have shown very similar patterns in SDS-gelelectrophoresis, which could hardly be used for species identification but they are characteristic for fresh or boiled muscles. Proteins of European potato cultivars and primitive cultivars from South America have almost identical SDS-patterns even if taken from boiled potatoes. Their patterns are different from the proteins of other European crops plants and may serve for detection of the presence of potatoes in food mixtures.

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Diese Arbeit ist Teil der Dissertation von I. de Wreede. Die Analyse der tierischen Proteine bearbeitete I. de Wreede.Sonderdruckanfragen an: I. de Wreede (Adresse siehe oben)     

Finite‐Element Implementation of a Self‐consistent Texture Model with a Hardening Law Based on Dislocation Densities

A self‐consistent texture model is implemented in the finite‐element code ABAQUS/Explicit®. Hardening of the slip systems is described by evolution laws for dislocation densities, and the Bauschinger effect is included. With these ingredients the cold rolling of an IF‐steel is simulated and the evolution of texture and anisotropy is examined. The use of the dislocation based hardening law is found to have a significant effect on the evolution of the anisotropic yield surface, but only very little influence on the texture. Furthermore, the hardening model is used to investigate the evolution of dislocation densities in differently oriented grains during plane strain compression. It is found that the dislocation density varies greatly depending on orientation, an observation which can help to explain the orientation dependence of recrystallization.     

Combining Acoustic Emission and Vibration Technologies Harbors Huge Potential for Material Characterization

The demand for raw materials is growing worldwide, in step with increasing world population and rising living standards of emerging countries. It is becoming more difficult to exploit primary raw materials because of declining ore grades and increasingly complicated mineralogies. Thus, the efficient and environmentally sustainable exploitation of primary resources using innovative technologies has emerged as an important research field to address these issues. An innovative approach is introduced to optimize process and quality control by combining acoustic emission (AE) and vibration technology. The general feasibility of these two technologies for material recognition and characterization is examined. The new approach was tested to determine whether coal could be distinguished from waste rock.