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501.
Bruce Anna Skye Thogmartin Wayne E. Trosen Chris Oberhauser Karen Gratton Claudio 《Landscape Ecology》2022,37(1):93-108
Landscape Ecology - It is estimated that over one billion milkweed stems need to be restored to sustain the eastern North American migratory population of monarch butterflies; where and in what... 相似文献
502.
Concetta Imperatore Filomena D’Aniello Anna Aiello Stefano Fiorucci Claudio D’Amore Valentina Sepe Marialuisa Menna 《Marine drugs》2014,12(4):2066-2078
Purification of the apolar extracts of the marine ascidian Phallusia fumigata, afforded two new sulfated sterols, phallusiasterols A (1) and B (2). The structures of the new compounds have been elucidated using mass spectrometry and NMR experiments. The effects of phallusiasterols A and B as modulators of pregnane-X-receptor (PXR) have been investigated. These studies revealed that phallusiasterol A induces PXR transactivation in HepG2 cells and stimulates the expression of the PXR target genes CYP3A4 and MDR1 in the same cell line. Molecular docking calculations suggested the theoretical binding mode of phallusiasterol A with hPXR and revealed that phallusiasterol A fitted well in the LBD of PXR. 相似文献
503.
Valentina Sepe Francesco Saverio Di Leva Claudio D’Amore Carmen Festa Simona De Marino Barbara Renga Maria Valeria D’Auria Ettore Novellino Vittorio Limongelli Lisette D’Souza Mahesh Majik Angela Zampella Stefano Fiorucci 《Marine drugs》2014,12(6):3091-3115
In recent years many sterols with unusual structures and promising biological profiles have been identified from marine sources. Here we report the isolation of a series of 24-alkylated-hydroxysteroids from the soft coral Sinularia kavarattiensis, acting as pregnane X receptor (PXR) modulators. Starting from this scaffold a number of derivatives were prepared and evaluated for their ability to activate the PXR by assessing transactivation and quantifying gene expression. Our study reveals that ergost-5-en-3β-ol (4) induces PXR transactivation in HepG2 cells and stimulates the expression of the PXR target gene CYP3A4. To shed light on the molecular basis of the interaction between these ligands and PXR, we investigated, through docking simulations, the binding mechanism of the most potent compound of the series, 4, to the PXR. Our findings provide useful functional and structural information to guide further investigations and drug design. 相似文献
504.
Review on iron availability in soil: interaction of Fe minerals,plants, and microbes 总被引:1,自引:0,他引:1
Claudio Colombo Giuseppe Palumbo Ji-Zheng He Roberto Pinton Stefano Cesco 《Journal of Soils and Sediments》2014,14(3):538-548
Purpose
The rationale of this paper is to review the state of the art regarding the biotic and abiotic reactions that can influence Fe availability in soils. In soil, the management-induced change from oxic to anoxic environment results in temporal and spatial variations of redox reactions, which, in turn, affect the Fe dynamics and Fe mineral constituents. Measuring the Fe forms in organic complexes and the interaction between bacteria and Fe is a major challenge in getting a better quantitative understanding of the dynamics of Fe in complex soil ecosystems.Materials and methods
We review the existing literature on chemical and biochemical processes in soils related with the availability of Fe that influences plant nutrition. We describe Fe acquisition by plant and bacteria, and the different Fe–organic complexes in order to understand their relationships and the role of Fe in the soil carbon cycle.Results and discussion
Although total Fe is generally high in soil, the magnitude of its available fraction is generally very low and is governed by very low solubility of Fe oxides. Plants and microorganisms can have different strategies in order to improve Fe uptake including the release of organic molecules and metabolites able to form complexes with FeIII. Microorganisms appear to be highly competitive for Fe compared with plant roots. Crystalline Fe and poorly crystalline (hydro)oxides are also able to influence the carbon storage in soil.Conclusion
The solubility of crystalline Fe minerals in soil is usually very low; however, the interaction with plant, microbes, and organic substance can improve the formation of soluble FeIII complexes and increase the availability of Fe for plant growth. Microbes release siderophores and plant exudates (e.g., phytosiderophores, organic acids, and flavonoids), which can bind and solubilize the Fe present in minerals. The improved understanding of this topic can enable the identification of effective solutions for remedying Fe deficiency or, alternatively, restricting the onset of its symptoms and yield’s limitations in crops. Therefore, development and testing of new analytical techniques and an integrated approach between soil biology and soil chemistry are important prerequisites. 相似文献505.
Puglisi Edoardo Zaccone Claudio Cappa Fabrizio Cocconcelli Pier Sandro Shotyk William Trevisan Marco Miano Teodoro M. 《Biology and Fertility of Soils》2014,50(5):815-826
Biology and Fertility of Soils - Peatlands are archives of extreme importance for the assessment of past ecological, environmental and climatic changes. The importance as natural archives is even... 相似文献
506.
Anfossi L Calderara M Baggiani C Giovannoli C Arletti E Giraudi G 《Journal of agricultural and food chemistry》2008,56(6):1852-1857
The official methods for the quantification of aflatoxin M1 in dairy products (cheese and yogurt) include extraction into dichloromethane or chloroform, evaporation of the solvent, partitioning of the reconstituted residue with hexane, and subsequent analysis. To secure a rapid and inexpensive screen for aflatoxin M1 contamination, a sensitive competitive ELISA, using a rabbit polyclonal antibody, was developed for measuring aflatoxin M1 in milk and used in a comparative study for measuring the extraction efficiency of aflatoxin M1 in aqueous or organic solvent buffers using yogurt samples. An aqueous sodium citrate solution was found to be suitable for extracting aflatoxin M1, thus eliminating the need for organic solvents. The citrate extraction proved to be efficient (recovery ranged from 70 to 124%) in fortified samples of very different kinds of dairy products, including yogurt and six types of cheese. Fourteen yogurt and cheese samples were extracted with citrate solution and analyzed by ELISA. A good correlation was observed (y=0.95x-0.59, r2=0.98) when the data were compared with those obtained through the official method, across a wide range of aflatoxin M1 contaminations (10-200 ng/kg). 相似文献
507.
Tanja Mimmo Luciano Cavani Riccardo Reggiani Claudio Marzadori Carlo Gessa 《Biology and Fertility of Soils》2008,44(3):521-526
This study investigated the interactions of CrIII and CrVI present as free metal ions or as organic CrIII (Cr-L) with a Ca-polygalacturonate
(Ca-PG) network. Ca-PG networks were treated with solutions of chromium (CrIII and CrVI) at different concentrations at three
different pH values. The Cr-L complex were obtained by water extraction of hydrolysed leather. The CrVI had almost no interaction
with the Ca-PG networks, whereas CrIII as a free metallic ion was strongly retained by the network. The calculated Langmuir
adsorption isotherms showed a twofold increase in maximum CrIII adsorption but a decrease in the affinity of the metal with
the Ca-PG networks. This would indicate that the different chromium species, i.e. CrIII and its hydrolytic species, interact
in a different way with the polygalacturonate chains. In addition, thermal analysis showed that CrIII sorption modified the
structure of the network. These modifications were reduced, and thermal stability increased if Ca-PG adsorbed Cr-L or L. Furthermore,
the treatment of Ca-PG with hydrolysed leather water extract-reduced CrIII sorption by 94%. The hydrolysed leather fraction
immobilized onto the Ca-PG networks probably consisted of peptides and could therefore represent an important source of organic
N. 相似文献
508.
Cavani L Ter Halle A Richard C Ciavatta C 《Journal of agricultural and food chemistry》2006,54(24):9160-9167
The use of protein hydrolysate-based fertilizers (PHF) as adjuvant for pesticides or herbicides has been proposed; however, the behaviors of mixtures of PHFs and pesticides under solar light are not known, and various photochemical reactions may occur. The photosensitizing properties of PHFs were investigated in water solutions (0.8 g of total organic carbon L(-1)) within the wavelength range of 300-450 nm, using furfuryl alcohol (FA) as a probe to test the involvement of singlet oxygen and Irgarol 1051 as an example of organic pollutant. Two commercial PHFs and one standard PHF were studied, all of the products being of animal origin. PHFs photosensitize the transformation of FA (10(-4) M), and the kinetics of FA disappearance follows an apparent first-order rate law. Through the use of sodium azide (1 x 10(-3) M) as singlet oxygen scavenger and deuterium oxide (D2O) for increasing the singlet oxygen lifetime it was shown that singlet oxygen contributes largely to the phototransformation of FA. The replacement of water by D2O increases the apparent first-order rate constant 6 times, whereas the addition of sodium azide reduces it by approximately 90%. These results are confirmed using Irgarol 1051 (10(-5) M). The photosensitizing properties of PHFs might be due to pigments naturally present in tissues from which they are extracted or to compounds generated during the production processes. 相似文献
509.
Fiorentino A D'Abrosca B Pacifico S Mastellone C Piscopo V Monaco P 《Journal of agricultural and food chemistry》2006,54(25):9592-9597
Carotenoid metabolites are common plant constituents with significant importance for the flavor and aroma of fruits. Three new carotenoid derivatives, (2E,4E)-8-hydroxy-2,7-dimethyl-2,4-decadiene-1,10-dioic acid 1-O-beta-D-glucopyranosyl ester (1), (2Z,4E)-8-beta-D-glucopyranosyloxy-2,7-dimethyl-2,4-decadiene-1,10-dioic acid (3), and 3,9-dihydroxymegastigmast-5-ene-3-O-[beta-D-glucopyranosyl-(1-->6)]-beta-D-glucopyranoside (5), as well as three known compounds, have been isolated from the ethanolic extract of peels of Cydonia vulgaris, the fruit of a shrub belonging to the same family as the apple. All the compounds were identified by spectroscopic techniques, especially 1D and 2D NMR. Antioxidant activities of all the isolated metabolites were assessed by measuring their ability to scavenge DPPH radical and superoxide radical (O2*-) and to induce the reduction of Mo(VI). 相似文献
510.
Hetz C Bernasconi P Fisher J Lee AH Bassik MC Antonsson B Brandt GS Iwakoshi NN Schinzel A Glimcher LH Korsmeyer SJ 《Science (New York, N.Y.)》2006,312(5773):572-576
Accumulation of misfolded protein in the endoplasmic reticulum (ER) triggers an adaptive stress response-termed the unfolded protein response (UPR)-mediated by the ER transmembrane protein kinase and endoribonuclease inositol-requiring enzyme-1alpha (IRE1alpha). We investigated UPR signaling events in mice in the absence of the proapoptotic BCL-2 family members BAX and BAK [double knockout (DKO)]. DKO mice responded abnormally to tunicamycin-induced ER stress in the liver, with extensive tissue damage and decreased expression of the IRE1 substrate X-box-binding protein 1 and its target genes. ER-stressed DKO cells showed deficient IRE1alpha signaling. BAX and BAK formed a protein complex with the cytosolic domain of IRE1alpha that was essential for IRE1alpha activation. Thus, BAX and BAK function at the ER membrane to activate IRE1alpha signaling and to provide a physical link between members of the core apoptotic pathway and the UPR. 相似文献