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Hamburg, Germany

Trox J.,Institute for Biological Chemistry and Nutrition | Vadivel V.,Institute for Biological Chemistry and Nutrition | Vetter W.,Institute of Food Chemistry | Stuetz W.,Institute for Biological Chemistry and Nutrition | And 4 more authors.
Journal of Agricultural and Food Chemistry | Year: 2010

In the present study, the effects of various conventional shelling methods (oil-bath roasting, direct steam roasting, drying, and open pan roasting) as well as a novel "Flores" hand-cracking method on the levels of bioactive compounds of cashew nut kernels were investigated. The raw cashew nut kernels were found to possess appreciable levels of certain bioactive compounds such as β-carotene (9.57 μg/100 g of DM), lutein (30.29 μg/100 g of DM), zeaxanthin (0.56 μg/100 g of DM), α-tocopherol (0.29 mg/100 g of DM), γ-tocopherol (1.10 mg/100 g of DM), thiamin (1.08 mg/100 g of DM), stearic acid (4.96 g/100 g of DM), oleic acid (21.87 g/100 g of DM), and linoleic acid (5.55 g/100 g of DM). All of the conventional shelling methods including oil-bath roasting, steam roasting, drying, and open pan roasting revealed a significant reduction, whereas the Flores hand-cracking method exhibited similar levels of carotenoids, thiamin, and unsaturated fatty acids in cashew nuts when compared to raw unprocessed samples. © 2010 American Chemical Society. Source

Ivana S.,University of Bucharest | Ivana S.,Asclepius 2008 Research and Development Center | Tuluca E.,Institute of Food Chemistry | Dinu C.P.,Carol Davila University of Medicine and Pharmacy | Dinu C.P.,Scientific Research Center for Defense and Ecology
Cellulose Chemistry and Technology | Year: 2013

The paper presents the results concerning the modifications in the sugar composition resulted from lignocellulosic substrates subjected to the action of lignolytic fungi: Pleurotus ostreatus and Phanerochaete chrysosporium. The substrates used were formed by various mixtures of corn cobs and oak tree leaves, oak tree sawdust and oak tree leaves, and oak tree bark - oak tree leaves, all in ratios of 2:1 (marked as mixtures I, II and III). The evaluation of the sugar composition of the substrates biodegraded by the above-mentioned fungi, for 30 days, was performed after hydrolysis, using IN sulfuric acid at 120 °C, for one hour, followed by sodium carbonate treatment until a pH of 5.8 was reached. The quantitative determinations were performed through gas chromatography. The gathered data showed that the highest degree of the heteropolysaccharide degradation corresponded to Pleurotus ostreatus, while the fungus Phanerochaete chrysosporium cultivated under the same conditions degraded carbohydrates at a lower level. Also, a large consumption of pentoses was recorded, evaluated through the variation of the xylose amounts, which rapidly decreased in case of the Pleurotus ostreatus microorganism, in comparison with the substrate inoculated by Phanerochaete chrysosporium. Similarly, the hexoses consumption levels (mainly of glucose) were quite modest in the case of Pleurotus ostreatus and quite significant for Phanerochaete chrysosporium. Source

Weiss A.,Institute of Food Chemistry | Brockmeyer J.,Institute of Food Chemistry
Toxins | Year: 2013

Enterohemorrhagic E. coli (EHEC) causes severe diseases in humans worldwide. One of its virulence factors is EspP, which belongs to the serine protease autotransporters of Enterobacteriaceae (SPATE) family. In this review we recapitulate the current data on prevalence, biogenesis, structural properties and functionality. EspP has been used to investigate mechanistic details of autotransport, and recent studies indicate that this transport mechanism is not autonomous but rather dependent on additional factors. Currently, five subtypes have been identified (EspPα-EspPε), with EspPα being associated with highly virulent EHEC serotypes and isolates from patients with severe disease. EspPα has been shown to degrade major proteins of the complement cascade, namely C3 and C5 and probably interferes with hemostasis by cleavage of coagulation factor V. Furthermore, EspPα is believed to contribute to biofilm formation perhaps by polymerization to rope-like structures. Together with the proteolytic activity, EspPα might ameliorate host colonization and interfere with host response. © 2013 by the authors; licensee MDPI, Basel, Switzerland. Source

Unterberg M.,University of Potsdam | Hubner F.,Institute of Food Chemistry | Humpf H.-U.,Institute of Food Chemistry | Lepikhov K.,Saarland University | And 3 more authors.
Toxicology Research | Year: 2014

This study aims to further mechanistically understand toxic modes of action after chronic inorganic arsenic exposure. Therefore long-term incubation studies in cultured cells were carried out, to display chronically attained changes, which cannot be observed in the generally applied in vitro short-term incubation studies. Particularly, the cytotoxic, genotoxic and epigenetic effects of an up to 21 days incubation of human urothelial (UROtsa) cells with pico- to nanomolar concentrations of iAsIII and its metabolite thio-DMAV were compared. After 21 days of incubation, cytotoxic effects were strongly enhanced in the case of iAsIII and might partly be due to glutathione depletion and genotoxic effects on the chromosomal level. These results are in strong contrast to cells exposed to thio-DMAV. Thus, cells seemed to be able to adapt to this arsenical, as indicated among others by an increase in the cellular glutathione level. Most interestingly, picomolar concentrations of both iAsIII and thio-DMAV caused global DNA hypomethylation in UROtsa cells, which was quantified in parallel by 5-medC immunostaining and a newly established, reliable, high resolution mass spectrometry (HRMS)-based test system. This is the first time that epigenetic effects are reported for thio-DMAV; iAsIII induced epigenetic effects occur in at least 8000 fold lower concentrations as reported in vitro before. The fact that both arsenicals cause DNA hypomethylation at really low, exposure-relevant concentrations in human urothelial cells suggests that this epigenetic effect might contribute to inorganic arsenic induced carcinogenicity, which for sure has to be further investigated in future studies. © The Royal Society of Chemistry 2014. Source

Masini T.,University of Groningen | Pilger J.,Max Planck Institute for Biophysical Chemistry | Kroezen B.S.,University of Groningen | Illarionov B.,Institute of Food Chemistry | And 4 more authors.
Chemical Science | Year: 2014

We applied for the first time an innovative ligand-based NMR methodology (STI) to a medicinal-chemistry project aimed at the development of inhibitors for the enzyme 1-deoxy-d-xylulose-5-phosphate synthase (DXS). DXS is the first enzyme of the 2C-methyl-d-erythritol-4-phosphate (MEP) pathway, present in most bacteria (and not in humans) and responsible for the synthesis of the essential isoprenoid precursors. We designed de novo a first generation of fragments, using Deinococcus radiodurans DXS as a model enzyme, targeting the thiamine diphosphate (TDP) pocket of DXS whilst also exploring the putative substrate-binding pocket, where selectivity over other human TDP-dependent enzymes could be gained. The STI methodology-suitable for weak binders-was essential to determine the binding mode in solution of one of the fragments, circumventing the requirement for an X-ray co-crystal structure, which is known to be particularly challenging for this specific enzyme and in general for weak binders. Based on this finding, we carried out fragment growing and optimisation, which led to a three-fold more potent fragment, about as potent as the well-established thiamine analogue deazathiamine. The STI methodology proved therefore its strong potential as a tool to support medicinal-chemistry projects in their early stages, especially when dealing with weak binders. © 2014 the Partner Organisations. Source

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