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101.
Insecticidal Metabolites from the Rhizomes of Veratrum album against Adults of Colorado Potato Beetle,Leptinotarsa decemlineata
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Tuba Aydin Ahmet Cakir Cavit Kazaz Neslihan Bayrak Yasin Bayir Yavuz Taşkesenligil 《化学与生物多样性》2014,11(8):1192-1204
The dried rhizomes of Veratrum album were individually extracted with CHCl3, acetone, and NH4OH/benzene to test the toxic effects against the Colorado potato beetle, Leptinotarsa decemlineata, which is an important agricultural pest. Fifteen compounds in various amounts were isolated from the extracts using column and thin‐layer chromatography. The chemical structures of 14 compounds were characterized as octacosan‐1‐ol ( 1 ), β‐sitosterol ( 2 ), stearic acid ( 3 ), diosgenin ( 4 ), resveratrol ( 5 ), wittifuran X ( 6 ), oxyresveratrol ( 7 ), β‐sitosterol 3‐O‐β‐D ‐glucopyranoside ( 8 ), diosgenin 3‐O‐α‐L ‐rhamnopyranosyl‐(1→2)‐β‐D ‐glucopyronoside ( 9 ), oxyresveratrol 3‐O‐β‐D ‐glucopyranoside ( 10 ), jervine ( 11 ), pseudojervine ( 13 ), 5,6‐dihydro‐1‐hydroxyjervine ( 14 ), and saccharose ( 15 ) using UV, IR, MS, 1H‐ and 13C‐NMR, and 2D‐NMR spectroscopic methods. However, the chemical structure of 12 , an oligosaccharide, has not fully been elucidated. Compounds 4, 6, 9 , and 10 were isolated from V. album rhizomes for the first time in the current study. The toxic effects of three extracts (acetone, CHCl3, and NH4OH/benzene) and six metabolites, 2, 2 + 4, 5, 7, 8 , and 11 , were evaluated against the Colorado potato beetle. The assay revealed that all three extracts, and compounds 7, 8 , and 11 exhibited potent toxic effects against this pest. This is the first report on the evaluation of the toxic effects of the extracts and secondary metabolites of V. album rhizomes against L. decemlineata. Based on these results, it can be concluded that the extracts can be used as natural insecticides. 相似文献
102.
Selmin Toplan Nuran Dariyerli Semra Ozdemir Dervis Ozcelik Emel U. Zengin Mehmet C. Akyolcu 《Biological trace element research》2013,152(3):373-378
The present study was conducted to explore the possible effects of different doses of lithium carbonate on thyroid functions, erythrocyte oxidant–antioxidant status, and osmotic fragility. Twenty-four Wistar-type male rats were equally divided into three groups: groups I and II received 0.1 and0.2 % lithium carbonate in their drinking water, respectively, for 30 days. The rats in group III served as controls, drinking tap water without added lithium. At the end of the experimental period, the erythrocyte osmotic fragility and the levels of triiodothyronine (T3), thyroxine (T4), thyroid-stimulating hormone (TSH), malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione (GSH) were measured in blood samples. Compared to controls, there was a statistically significant increase of TSH but decreases of the T3 and T4 levels in group II. Both experimental groups showed a statistically significant increase of the maximum osmotic fragility limit. The minimum osmotic fragility values of the animals in group II were statistically higher than those of controls. The standard hemolytic increment curve of both experimental groups was shifted to the right when compared to the curve obtained from the controls. Also, relative to controls, the activities of MDA and SOD were significantly higher and the GSH level lower in group II, but not so in group I. The results of the present study show that treatment with lithium carbonate may result in thyroid function abnormalities, increased oxidative damage, and possible compromise of the erythrocyte membrane integrity resulting from increased osmotic fragility. 相似文献
103.
An empirical test of the relative and combined effects of land‐cover and climate change on local colonization and extinction
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Land‐cover and climate change are two main drivers of changes in species ranges. Yet, the majority of studies investigating the impacts of global change on biodiversity focus on one global change driver and usually use simulations to project biodiversity responses to future conditions. We conduct an empirical test of the relative and combined effects of land‐cover and climate change on species occurrence changes. Specifically, we examine whether observed local colonization and extinctions of North American birds between 1981–1985 and 2001–2005 are correlated with land‐cover and climate change and whether bird life history and ecological traits explain interspecific variation in observed occurrence changes. We fit logistic regression models to test the impact of physical land‐cover change, changes in net primary productivity, winter precipitation, mean summer temperature, and mean winter temperature on the probability of Ontario breeding bird local colonization and extinction. Models with climate change, land‐cover change, and the combination of these two drivers were the top ranked models of local colonization for 30%, 27%, and 29% of species, respectively. Conversely, models with climate change, land‐cover change, and the combination of these two drivers were the top ranked models of local extinction for 61%, 7%, and 9% of species, respectively. The quantitative impacts of land‐cover and climate change variables also vary among bird species. We then fit linear regression models to test whether the variation in regional colonization and extinction rate could be explained by mean body mass, migratory strategy, and habitat preference of birds. Overall, species traits were weakly correlated with heterogeneity in species occurrence changes. We provide empirical evidence showing that land‐cover change, climate change, and the combination of multiple global change drivers can differentially explain observed species local colonization and extinction. 相似文献
104.
The effect of cyclic anaerobic–aerobic conditions on the biodegradative capability of the mixed microbial culture for the
azo dye Remazol Brilliant Violet 5R (RBV-5R) was investigated in the sequencing batch reactor (SBR) fed with a synthetic textile
wastewater. The SBR had a 12-h cycle time with anaerobic–aerobic periods of 3/9, 6/6 and 9/3 h. General SBR performance was
assessed by measurement of catabolic enzymes (catechol 2,3-dioxygenase, azo reductase), chemical oxygen demand (COD), color
and amount of aromatic amines. In this study, under steady-state conditions, the anaerobic period of the cyclic SBR was found
to allow the reductive decolorization of azo dye. Longer anaerobic periods resulted in higher color removal efficiencies,
approximately 71% for the 3-h, 87% for 6-h and 92% for the 9-h duration. Total COD removal efficiencies were over 84% under
each of the cyclic conditions and increased as the length of the anaerobic period was increased; however, the highest color
removal rate was attained for the cycle with the shortest anaerobic period of 3 h. During the decolorization of RBV-5R, two
sulfonated aromatic amines (benzene based and naphthalene based) were formed. Additionally, anaerobic azo reductase enzyme
was found to be positively affected with the increasing duration of the anaerobic period; however; it was vice versa for the
aerobic catechol 2,3-dioxygenase (C23DO) enzyme. 相似文献
105.
Background
Large-scale compilation of gene expression microarray datasets across diverse biological phenotypes provided a means of gathering a priori knowledge in the form of identification and annotation of bimodal genes in the human and mouse genomes. These switch-like genes consist of 15% of known human genes, and are enriched with genes coding for extracellular and membrane proteins. It is of interest to determine the prediction potential of bimodal genes for class discovery in large-scale datasets. 相似文献106.
107.
Agar Guleray Taspinar Mahmut Sinan Yildirim Ertan Aydin Murat Yuce Merve 《Journal of Plant Growth Regulation》2020,39(2):897-904
Journal of Plant Growth Regulation - Heavy metal pollution, which is one of the most important environmental problems, has a significant effect on plant growth and development. Plants influence all... 相似文献
108.
Plasma and inflammatory fluid kininogen levels, and blood and inflammatory fluid free kinin levels were determined in rats 24 h after the injection of carrageenin into an air pouch. Plasma T-kininogen levels increased 7-fold. In the inflammatory fluid levels reached 8 μg/ml. Blood levels of free kinin showed a 5-fold increase. The kinins were identified on HPLC as T-kinin (Ile-Ser-bradykinin) and bradykinin, 63 and 37%, respectively. These results indicate for the first time that free T-kinin as well as bradykinin is released during an inflammatory response in rat and confirms our previous finding that T-kininogen may be a major acutephase protein in inflammation.
T-kinin T-kininogen Bradykinin Inflammation Acute-phase protein Carrageenin 相似文献
109.
Trichotoxin A40. Purification by counter-current distribution and sequencing of isolated fragments 总被引:2,自引:0,他引:2
The isolation of the membrane-modifying polypeptide antibiotics from the mycelium of Trichoderma viride 5242 was optimized via extraction with dichloromethane and chromatography on Sephadex LH-20. The components trichotoxin A40 and A50 were separated from each other and purified by multiplicative counter-current distribution. The sequence of proteinase-resistant trichotoxin A40 was determined by combined gas chromatography and mass spectrometry of three isolated N-acetylated dodecapeptides and two N-prolylhexapeptides obtained after selective trifluoroacetolysis. Including amino acid exchanges due to natural microheterogeneity, the sequence is Ac-Aib-Gly(LAla)-Aib-LLeu-Aib-LGln-Aib-Aib-Aib(LAla )-LAla-Aib-Aib-LPro-LLeu -Aib-DIva(Aib)-LGlu-LValol. In contrast to the eicosapeptide alamethicin, trichotoxin A40 contains only 18 residues, with a higher proportion of alpha-aminoisobutyric acid (Aib), C-terminal L-valinol (Vol), one D-isovaline (Iva) and no proline at the N-terminal part. 相似文献
110.
Xinbo Yang Erkan Aydin Hang Xu Jingxuan Kang Mohamed Hedhili Wenzhu Liu Yimao Wan Jun Peng Christian Samundsett Andres Cuevas Stefaan De Wolf 《Liver Transplantation》2018,8(20)
Minimizing carrier recombination at contact regions by using carrier‐selective contact materials, instead of heavily doping the silicon, has attracted considerable attention for high‐efficiency, low‐cost crystalline silicon (c‐Si) solar cells. A novel electron‐selective, passivating contact for c‐Si solar cells is presented. Tantalum nitride (TaN x ) thin films deposited by atomic layer deposition are demonstrated to provide excellent electron‐transporting and hole‐blocking properties to the silicon surface, due to their small conduction band offset and large valence band offset. Thin TaNx interlayers provide moderate passivation of the silicon surfaces while simultaneously allowing a low contact resistivity to n‐type silicon. A power conversion efficiency (PCE) of over 20% is demonstrated with c‐Si solar cells featuring a simple full‐area electron‐selective TaNx contact, which significantly improves the fill factor and the open circuit voltage (Voc) and hence provides the higher PCE. The work opens up the possibility of using metal nitrides, instead of metal oxides, as carrier‐selective contacts or electron transport layers for photovoltaic devices. 相似文献