2,194 research outputs found

    Bioactive secondary metabolites from the endophytic fungus Chaetomium sp. isolated from Salvia officinalis growing in Morocco

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    This study reports the chemical investigation and cytotoxic activity of the secondary metabolites produced by the endophytic fungus Chaetomium sp. isolated from Salvia officinalis growing in Morocco. This plant was collected from the Beni-Mellal Mountain in Morocco and belongs to the Lamiaceae family and is named in Morocco 'Salmia'. The endophytic fungus Chaetomium sp. was isolated from the tissues of the stem of this plant. The fungal strain was identified by PCR. The crude organic extract of the fungal strain was proven to be active when tested for cytotoxicity against L5178Y mouse lymphoma cells. Chemical investigation of the secondary metabolites showed that cochliodinol is the main component beside isocochliodinol. The structures of the isolated compounds were determined on the basis of NMR analysis (1H, 13C, COSY and HMBC) as well as by mass spectrometry using ESI (Electron Spray Ionisation) as source

    Thermochemical stability of low-iron, manganese-enriched olivine in astrophysical environments

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    Low-iron, manganese-enriched (LIME) olivine grains are found in cometary samples returned by the Stardust mission from comet 81P/Wild 2. Similar grains are found in primitive meteoritic clasts and unequilibrated meteorite matrix. LIME olivine is thermodynamically stable in a vapor of solar composition at high temperature at total pressures of a millibar to a microbar, but enrichment of solar composition vapor in a dust of chondritic composition causes the FeO/MnO ratio of olivine to increase. The compositions of LIME olivines in primitive materials indicate oxygen fugacities close to those of a very reducing vapor of solar composition. The compositional zoning of LIME olivines in amoeboid olivine aggregates is consistent with equilibration with nebular vapor in the stability field of olivine, without re-equilibration at lower temperatures. A similar history is likely for LIME olivines found in comet samples and in interplanetary dust particles. LIME olivine is not likely to persist in nebular conditions in which silicate liquids are stable

    Study of the system of middle atmosphere-ionosphere using remote-sensing data

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    In the present investigation, the methods of statistical spectral analysis are employed for a study of the quasi-periodic changes of state parameters of the middle atmosphere and the ionosphere, taking into account oscillations with periods of several days. The considered oscillations are typical for planetary waves. The theory and empirical findings regarding transient planetary waves are utilized as a basis for the concepts employed in the data analysis and for the interpretation of the results. The results of the investigation show a presence of coherent variations in the time series of radiation density measurements and other state parameters for the middle atmosphere and the ionosphere. The existence of presumably dynamic coupling processes can be recognized in oscillations with periods of about 16 or 5 days

    Antimicrobial activities of marine fungi from Malaysia

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    Copyright 2011 Elsevier B.V., All rights reserved.Peer reviewedPublisher PD

    Formylation of mischarged E. coli tRNAMetf

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    Application of metabolomics and molecular networking in investigating the chemical profile and antitrypanosomal activity of British bluebells (Hyacinthoides non-scripta)

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    Bulb, leaf, scape and flower samples of British bluebells (Hyacinthoides non-scripta) were collected regularly for one growth period. Methanolic extracts of freeze-dried and ground samples showed antitrypanosomal activity, giving more than 50% inhibition, for 20 out of 41 samples. High-resolution mass spectrometry was used in the dereplication of the methanolic extracts of the different plant parts. The results revealed differences in the chemical profile with bulb samples being distinctly different from all aerial parts. High molecular weight metabolites were more abundant in the flowers, shoots and leaves compared to smaller molecular weight ones in the bulbs. The anti-trypanosomal activity of the extracts was linked to the accumulation of high molecular weight compounds, which were matched with saponin glycosides, while triterpenoids and steroids occurred in the inactive extracts. Dereplication studies were employed to identify the significant metabolites via chemotaxonomic filtration and considering their previously reported bioactivities. Molecular networking was implemented to look for similarities in fragmentation patterns between the isolated saponin glycoside at m/z 1445.64 [M + formic-H]− equivalent to C64H104O33 and the putatively found active metabolite at m/z 1283.58 [M + formic-H]− corresponding to scillanoside L-1. A combination of metabolomics and bioactivity-guided approaches resulted in the isolation of a norlanostane-type saponin glycoside with antitrypanosomal activity of 98.9% inhibition at 20 µM

    \u3ci\u3eFinal Report of the Minnesota Tax Study Commission\u3c/i\u3e

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    Chapter 6: The Tax System and Intergovernmental Linkages, authored by John Bartle, UNO faculty member. This volume contains state and local tax policy recommendations, placed within the context of changing economic structures, demographic trends and institutional relationships.https://digitalcommons.unomaha.edu/facultybooks/1171/thumbnail.jp

    Bioactive secondary metabolites from the endophytic fungus Chaetomium sp. isolated from Salvia officinalis growing in Morocco

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    This study reports the chemical investigation and cytotoxic activity of the secondary metabolites produced by the endophytic fungus Chaetomium sp. isolated from Salvia officinalis growing in Morocco. This plant was collected from the Beni-Mellal Mountain in Morocco and belongs to the Lamiaceae family and is named in Morocco “Salmia”. The endophytic fungus Chaetomium sp. was isolated from the tissues of the stem of this plant. The fungal strain was identified by PCR. The crude organic extract of the fungal strain was proven to be active when tested for cytotoxicity against L5178Y mouse lymphoma cells. Chemical investigation of the secondary metabolites showed that cochliodinol is the main component beside isocochliodinol. The structures of the isolated compounds were determined on the basis of NMR analysis (1H, 13C, COSY and HMBC) as well as by mass spectrometry using ESI (Electron Spray Ionisation) as source

    CPT Violation Implies Violation of Lorentz Invariance

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    An interacting theory that violates CPT invariance necessarily violates Lorentz invariance. On the other hand, CPT invariance is not sufficient for out-of-cone Lorentz invariance. Theories that violate CPT by having different particle and antiparticle masses must be nonlocal.Comment: Minor changes in the published versio
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