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1.
Gangarapu Kiran Manda Sarangapani Thumma Gouthami Anreddy Rama Narsimha reddy 《毒物与环境化学》2013,95(3):367-378
In the present study, the synthesis of new bis-isatin carbohydrazone derivatives and their antimicrobial and antioxidant activities were investigated. The structures of new compounds were elucidated by Fourier transform infrared, 1H nuclear magnetic resonance and mass spectra. The antimicrobial activity of the compounds was determined by using the two-fold serial dilution technique against various bacterial and fungal species in comparison to standard drugs. All synthesized compounds displayed a broad spectrum of activities with minimum inhibitory concentration values ranging from 6.25 to 100 μg/ml against tested microorganisms. The in vitro antioxidant activity was evaluated using 1,1-diphenyl-2-picryl-hydrazyl and hydrogen peroxide (H2O2), and the total antioxidant capacity by a phosphomolybdenum assay and their ability to chelate ferrous iron. In general, the derivatives were found to exhibit antioxidant activity. Further, the compounds with electron-withdrawing groups at the C5 position demonstrated significant antimicrobial and antioxidant activities. 相似文献
2.
Many sites of former ammunition plants are contaminated with the explosive 2,4,6-trinitrotoluene, its derivatives and reduction products. Such nitroaromatic compounds have a high human and ecotoxic potential. Plant uptake of these organic pollutants is known and could be confirmed under field conditions. In this paper rhizospheric soil was analyzed to characterize the effect of vegetation on TNT-contaminated soil. Common beans (Phaseolus vulgaris) were used as test plants. The experiments were performed on two areas with different TNT concentrations. The data reveal a significant decrease of extractable TNT in rhizospheric soil by a factor of 5 to 6 during the vegetation period. On the area with high TNT concentration, an enrichment of nitroaromatic compounds in root tissue was found compared to the rhizospheric soil. Aminodinitrotoluene could be confirmed as the primary pollutant in the root. These results refer to a potential application of plants to biological remediation of soil contaminated with ammunition-specific pollutants. 相似文献
3.
许多有机化合物自身没有致癌毒性,但进入生物体内,经过体内代谢酶的催化后转化成活性中间体,与DNA形成共价化合物.这些间接的损伤会最终导致DNA分子结构和功能的变化,对人类的健康造成威胁.因此,建立一种快速有效的方法检测间接致癌化合物对DNA的损伤,成为当前研究的热点.论文建立了一种新型的光电化学生物传感器来检测有机化合物苯乙烯对DNA的间接损伤效应,该传感器以层层自组装的方式将光电信号分子、双链DNA和血红蛋白组装在半导体电极上.在H2O2存在的条件下,传感膜中的血红蛋白可将苯乙烯转化为氧化苯乙烯,氧化苯乙烯扩散到膜内,与DNA形成加合物,引起DNA结构变化,导致光电分子光电流信号的增加.实验中,将修饰好的电极置于终浓度为2mM H2O2和2%苯乙烯(体积比)的混合液(pH7.3的磷酸缓冲液配制)中反应一段时间后,在电解质溶液中进行光电流检测.实验结果表明,光电流信号随着反应时间逐渐升高,在30min后趋于稳定,表明苯乙烯在传感膜上的氧化和DNA的损伤反应基本完成.与反应前相比,反应后光电流增加了40%,并且酶催化苯乙烯生成的氧化苯乙烯经紫外可见光谱得到验证.论文建立的光电化学生物传感器模拟了体内DNA损伤反应过程,能快速有效地检测苯乙烯对DNA的间接损伤效应,有望为有机化合物潜在基因毒性的风险评估提供一个快速筛查工具。 相似文献
4.
堆肥处理对污泥腐殖物质组成和光谱学特征的影响 总被引:9,自引:0,他引:9
采用凝胶(Sephadex G-75)色谱、荧光光谱和红外光谱法研究了污泥堆肥的HA和FA在堆制前后的组成与结构特征变化.凝胶色谱分析表明,污泥经过63d堆腐后,HA中大分子组分含量明显提高;而FA则由不同分子量物质组成,其中小分子量物质占主要部分,在堆腐以后,FA中大分子物质含量下降30%,小分子量物质含量则相对增加.同时,荧光光谱、红外光谱的结果表明:随着污泥堆肥的进行,HA中有机物不饱和结构的多聚化或联合程度增大,芳香结构物质含量增加;但经过堆制的FA具有更多的结构简单的低分子量物质和更低的芳构化水平. 相似文献
5.
Detmar Beyersmann 《毒物与环境化学》2013,95(1-4):61-67
The biochemical speciation of chromium compounds in mammalian cells is discussed with respect to uptake, metabolism, DNA binding and damaging. Whereas soluble hexavalent chromium is taken up rapidly and accumulated intracellularly after its reduction, compounds of trivalent chromium penetrate biomembranes about three orders of magnitude slower. Cr(VI) after its uptake is metabolised by electron donating compounds via Cr(V) to Cr(III) compounds. Chromium from various Cr(III) compounds, but not chromate, binds to chromatin in isolated cell nuclei. The DNA‐protein crosslinks and DNA strand breaks observed in rat liver and kidney after chromate administration are also found in vitro, when Cr(III) compounds (but not chromate) interacts with isolated nuclei. In the Chinese Hamster cell HGPRT mutation assay, three out of four tested Cr(III) complexes were found to be mutagenic. In a direct DNA strand break assay with supercoiled bacteriophage PM 2 DNA, neither chromate nor the four Cr(III) compounds tested caused nicks. However, the combined action of chromate plus glutathione as well as the isolated complex of pentavalent chromium, Na4Cr(glutathione)4, did cause DNA breaks. Reactive oxygen species are inferred to be the ultimate DNA nicking agents in this assay. In conclusion there appear to be two mechanisms of chromate genotoxicity; one with direct DNA damage caused by Cr(V) species and one via DNA‐protein crosslinks formed with Cr(III), the final reduction state of chromate. 相似文献
6.
Summary. Pyrrolizidine alkaloids (PAs) present a model system in the investigation of tritrophic interactions mediated by plant secondary compounds. However, their toxicity for insect herbivores has never been experimentally proven. Here, we demonstrate the toxic effects of a PA on growth and survival of the eri silk moth Philosamia ricini. In a feeding experiment, larvae of this generalist herbivore fed with an artificial PA diet gained weight significantly slower than control animals, and died as pupae. We suggest that derivatives of the ingested PA N-oxide damage developmental functions during metamorphosis. A tracer test with [14C]senecionine N-oxide revealed that the caterpillars lack adaptations that would prevent conversion of the chemical into the pro-toxic free base. In contrast, the PA adapted leaf beetle Longitarsus anchusae accumulates PAs as N-oxides. We tested the purpose of sequestration in this species as defence against predators. Through a series of prey choice experiments with three carabid predator species, chemically non-protected bark beetle pupae were chosen almost uniformly over L. anchusae pupae. In a following choice test with one of these predators, artificially PA-treated mealworm segments deterred the predator from feeding. Overall the study corroborates the immediate toxic effect of PAs on non-adapted herbivores and the protective effect that adapted insects may gain by sequestering them. It thereby underlines the potential for PAs to play a central role in multitrophic interactions between plants, phytophages and their predators. 相似文献
7.
Fuqiang Liu Mingfang Xia Zhenghao Fei Jinlong Chen Aimin Li 《Frontiers of Environmental Science & Engineering》2007,1(1):73-78
Both bottle-point and column-feeding experiments involving different solutes and sorbents were carried out to investigate the adsorption selectivity and separation performance of salicylic acid and 5-sulfosalicylic acid. Their adsorption isotherms onto such hypercrosslinked polymeric adsorbents as NDA-100 and NDA-99 could be well described by the Freundlich equations whose characteristics describe extrathermic and favorable adsorption processes. The adsorption towards NDA-100 mainly depended on the π-π interaction, while that towards NDA-99 was extremely influenced by the static-electric interaction. Additionally, the adsorptive capacity of salicylic acid on NDA-99 decreased while it increased on NDA-100 with the presence of 5-sulfosalicylic acid in the adsorptive environment as the competitive component. Comparatively, the adsorption capacity of 5-sulfosalicylic acid decreased on both resins with salicylic acid as the competitive component. In fact, the difference in the interaction between adsorbent and adsorbate resulted in the straight antagonism on the effective adsorption sites on the adsorbent. In conclusion, the adsorption selectivity of salicylic acid onto NDA-100 was obviously larger than that onto NDA-99 with the existence of 5-sulfosalicylic acid in the adsorptive environment. A satisfactory separation and recovery of tested solutes in aqueous phase could be foreseeably achieved by the sequencing adsorption technique involving NDA-100 as well as NDA-99. 相似文献
8.
Michael Wink Angelika Hofer Martin Bilfinger Elke Englert Martinus Martin Dietrich Schneider 《Chemoecology》1993,4(2):93-107
Summary The palatability of plants was studied in young, immature and adult geese of three species,Anser anser, Anser indicus andBranta canadensis, with respect to secondary plant metabolites. In their first 1–4 weeks of life, hand-reared goslings feed on a wide variety of plants, more or less irrespective of their allelochemical contents. Older birds become more selective, but still consume plants which are normally considered to be unpalatable or even toxic for other animals. Choice experiments were performed with pure secondary metabolites which were offered on otherwise highly palatable food items, such as leaves ofTaraxacum officinale. These experiments revealed a similar trend, in that very young goslings discriminate their food much less than older goslings or adult geese. In general, food contaminated with essential oils was rejected, whereas alkaloids, glycosides, amines and sulfur compounds were tolerated to a remarkable degree. In consequence, especially young, but also adult geese must have a high capacity to tolerate and/or to detoxify dietary allelochemicals. Another detoxification mechanism became evident during the experiments: geese ingest soil and mud quite regularly. It could be shown experimentally that the respective soil had a high capacity to bind alkaloids. We assume that geophagy is a means (besides a presumed active detoxification in the liver) to adsorb and thus reduce the contents of dietary allelochemicals. 相似文献
9.
Impact of cannibalism on predator-prey dynamics: size-structured interactions and apparent mutualism
Direct and indirect interactions between two prey species can strongly alter the dynamics of predator-prey systems. Most predators are cannibalistic, and as a consequence, even systems with only one predator and one prey include two prey types: conspecifics and heterospecifics. The effects of the complex direct and indirect interactions that emerge in such cannibalistic systems are still poorly understood. This study examined how the indirect interaction between conspecific and heterospecific prey affects cannibalism and predation rates and how the direct interactions between both species indirectly alter the effect of the cannibalistic predator. I tested for these effects using larvae of the stream salamanders Eurycea cirrigera (prey) and Pseudotriton ruber (cannibalistic predator) by manipulating the relative densities of the conspecific and heterospecific prey in the presence and absence of the predator in experimental streams. The rates of cannibalism and heterospecific predation were proportional to the respective densities and negatively correlated, indicating a positive indirect interaction between conspecific and heterospecific prey, similar to "apparent mutualism." Direct interactions between prey species did not alter the effect of the predator. Although both types of prey showed a similar 30% reduction in night activity and switch in microhabitat use in response to the presence of the predator, cannibalism rates were three times higher than heterospecific predation rates irrespective of the relative densities of the two types of prey. Cumulative predation risks differed even more due to the 48% lower growth rate of conspecific prey. Detailed laboratory experiments suggest that the 3:1 difference in cannibalism and predation rate was due to the higher efficiency of heterospecific prey in escaping immediate attacks. However, no difference was observed when the predator was a closely related salamander species, Gyrinophilus porphyriticus, indicating that this difference is species specific. This demonstrates that cannibalism can result in the coupling of predator and prey mortality rates that strongly determines the dynamics of predator-prey systems. 相似文献
10.
Chingoileima Maibam Patrick Fink Giovanna Romano Maria Cristina Buia Maria Cristina Gambi Maria Beatrice Scipione Francesco Paolo Patti Maurizio Lorenti Emanuela Butera Valerio Zupo 《Marine Biology》2014,161(7):1639-1652
Plants evolve the production of wound-activated compounds (WACs) to reduce grazing pressure. In addition, several plant-produced WACs are recognized by various invertebrates, playing the role of infochemicals. Due to co-evolutionary processes, some invertebrates recognize plant infochemicals and use them to identify possible prey, detect the presence of predators or identify algae containing various classes of toxic metabolites. Different metabolites present in the same algae can play the role of toxins, infochemicals or both simultaneously. We investigated the infochemical activity of compounds extracted from three diatoms epiphytes of the seagrass Posidonia oceanica, by conducting choice experiments on invertebrates living in the same community or in close proximity. Furthermore, the specific toxicity of the extracts obtained from the same algae was tested on sea urchin embryos using a standard bioassay procedure, to detect the presence of toxins. The comparison of the two effects demonstrated that invertebrates are subjected to diatom wound-activated toxicants when these algae are not associated with their own habitat, but they are able to recognize volatile infochemicals derived from diatoms associated with their habitats. The specific toxicity of WACs was shown to be inversely correlated to the perceptive ability of invertebrates towards volatile compounds liberated by the same algae. Hence, when the recognition of specific algae by a given invertebrate species evolves, their detrimental effects on the receiving organism may be lost. 相似文献
11.
Xianying Ma Xinhui Zhou Mengjie Zhao Wenzhuo Deng Yanxiao Cao Junfeng Wu Jingcheng Zhou 《Frontiers of Environmental Science & Engineering》2022,16(1):3
12.
Floral scents are known as an olfactory signal for attracting pollinators, but why the flowers pollinated by highly specialised pollinators emit scents consisting of mixtures of many compounds and dominated by one or a few compounds is still poorly understood. We supposed that each (especially characteristic) chemical in floral scents may play a specific role in mediating pollinator behaviours and tested this supposition in a fig-fig wasp mutualism. Ficus curtipes is obligately pollinated by an undescribed Eupristina species. In the scent of F. curtipes receptive figs, over 50 compounds have been identified, and the scent is dominated by two compounds, 6-methyl-5-hepten-2-ol (OL) and 6-methyl-5-hepten-2-one (NE). We therefore tested the roles of the two major chemicals in mediating the pollinator behaviours. Our results show that OL and NE, respectively, act as a long-distance attractant and a fig-entry behaviour stimulant to the obligate pollinator wasp. Namely, OL attracts the wasps to the figs and NE guides the wasps into the figs. This finding on the work division of floral scent compounds partially explains the maintenance mechanism of the fig-fig wasp mutualism and the significance of the chemical diversity of floral scent in plant–pollinator interactions, especially in specialised pollination systems. 相似文献
13.
G. Bronzetti A. Galli P. Boccardo R. Vellosi R. Del Carratore E. Sabbioni 《毒物与环境化学》2013,95(1-2):103-111
The genotoxicity of chromium chloride was investigated in cells of D7 strain of Saccharomyces cerevisiae harvested either from logarithmic or stationary growth phase. A weak induction of mifotic gene conversion and point reverse mutation was obtained when the incubations were performed using phosphate buffer. No genetic effect was observed when the incubations were performed using Tris‐HCl buffer. The experiments with 51Cr radiotracer demonstrated that Cr3+ ion enters the yeast cells and binds to DNA even if the incubation mixture was performed with Tris HCl buffer. This behaviour could be due to the highest concentration of CrCl3 that cause some damages to cytoplasmatic membrane. 相似文献
14.
Aditya AK Chattopadhyay S Mitra S 《Journal of environmental biology / Academy of Environmental Biology, India》2002,23(1):61-64
Adult pre-spawning fish Labeo rohita were sublethally (1/5th 96h LC50) exposed to mercuric chloride and metacid-50 (methyl parathion). Accumulation of mercury and methyl parathion was studied and it was found that pre-spawning ovary appears as a potent organ for deposition of both the pollutants. RNA/DNA ratio of the control and treated fish were studied. It was found that the signifcant decrease in RNA/DNA ratio occurs after 9 and 30 days of exposure for mercury and 30 days for methyl parathion. Fluorescence microscopic studies by acridine orange staining method were also performed to show how much it is related to biochemical alterations. In some cases loss of metachromasia is correlated with the fall in RNA/DNA ratio. Some other abnormalities like fall in stage II: stage I oocyte ratio and necrosis was also observed. 相似文献
15.
Louis Hautier Jean-Claude Grégoire Jérôme de Schauwers Gilles San Martin Pierre Callier Jean-Pierre Jansen Jean-Christophe de Biseau 《Chemoecology》2008,18(3):191-196
Summary. Under laboratory conditions, the multicolored Asian lady beetle, Harmonia axyridis is well known as an intraguild predator of other ladybirds. However the real impact of this exotic species on native species
was poorly investigated in the field. Because many ladybird species produce alkaloids as defensive compounds, we propose here
a new method of intraguild predation monitoring in coccinellids based on alkaloid quantification by GC-MS. In laboratory experiments,
adaline was unambiguously detected in fourth instar larvae of H. axyridis having ingested one egg or one first instar larva of Adalia bipunctata. Although prey alkaloids in the predator decreased with time, traces were still detected in pupae, exuviae and imagines of
H. axyridis having ingested one prey when they were fourth instar larvae. Analysis of H. axyridis larvae collected in two potato fields shows for the first time in Europe the presence of exogenous alkaloids in 9 out of
28 individuals tested. This new method of intraguild predation detection could be used more widely to follow the interactions
between predators and potential chemically defended insect preys. 相似文献
16.
A dynamic plot-scale model PROGRASS was developed to simulate the seasonal and inter-annual dynamics of productive, cut grass/clover mixtures in response to management, and specifically to examine the role of root development on grass/clover interactions. The model was parameterized by virtue of data for dry matter yield, leaf area index, root mass, soil mineral N uptake and biological N fixation from a long-term field trial in north-eastern Switzerland. It was tested using 5 years of independent data for yield and clover fraction from a field experiment with two management regimes carried out on the Swiss Central Plateau. The results of transient simulations indicated that under intensive fertilization grass dominance was initiated by preferential allocation of assimilates to the roots. The rapid growth of the grass root system lowered the substrate C:N ratio, favouring carbon allocation to the shoot, which eventually provided competitive advantages with respect to light interception. Under extensive management, limited N acquisition capacity of the grass root system maintained preferential allocation to the roots, limiting shoot development in the grass and leading to clover dominance. Co-existence regimes with dominance by one of the components were also found in equilibrium experiments, with a transition regime from clover to grass dominance for annual N applications in the range 100–200 kg N ha−1 y−1 that reflected adjustments of the root system to fertilization. It is concluded that the dynamics of grass/clover mixtures is driven by negative and positive feedbacks in the soil–plant system that are strongly controlled by root development and therefore by the allocation patterns of the grass component. 相似文献
17.
18.
Growth as an integrative parameter of all physiological processes was measured in young sporophytes of temperate Laminaria digitata, Laminaria saccharina and Laminaria hyperborea exposed in the laboratory to irradiance consisting of either only photosynthetically active radiation (PAR) or to a spectrum
including ultraviolet radiation (UVR) (PAR+UVA+UVB) by use of cut-off glass filters. Size increment was measured every 10 min
over a period of 18–21 days using growth chambers with on-line video measuring technique. In the chamber, plants were grown
at 10±2°C and 16:8 h light–dark cycles with 6 h additional UVR exposure in the middle of the light period. Tissue morphology
and absorption spectra were measured in untreated young sporophytes while chlorophyll a content and DNA damage were measured
in treated thalli at the end of the experiment. Sensitivity of growth under UVR was found to be related to the observed upper
depth distribution limit of the upper sublittoral L. digitata, upper to mid sublittoral L. saccharina and lower sublittoral L. hyperborea. Tissue DNA damage is, however, dependent on thallus thickness which minimizes UVR effect where outer cell layers shade inner
cells and provide longer pathlength for UVR. Exposure to UVR causes cellular, enzymatic and molecular damage. Presence of
UV-absorbing compounds further reduces effective UVR from reaching physiological targets. The cost of producing higher amount
of UV-absorbing compounds and effective DNA repair mechanism can, however, divert photosynthate at the expense of growth.
Tissue chlorophyll a content was not significantly different between treatments suggesting a capacity for acclimation to moderate
UVR fluence. Growth acclimation to repeated UVR exposure was observed within a period of 12 days while growth inhibition was
observed after a longer UVR exposure period of 21 days. The results give further insight into the effects of UVR on the cellular
level and show how ecological parameters such as the upper depth distribution limit are dependent on cellular processes. 相似文献
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20.
Cristina Zago Gabriele Capodaglio Carlo Barbante Michele Giani Ivo Moret Giuseppe Scarponi Paolo Cescon 《Chemistry and Ecology》2002,18(1):39-51
In the present study the concentrations of cobalt, copper, iron, manganese, zinc were analysed and the speciation of copper and zinc performed, with a summer and winter sampling, for two areas in the Northern Adriatic Sea and crossing at the farthest zones of the Po river-sea water interface. Results show that when salinity increases the concentrations of all investigated metals (with the exception of cobalt) present some degree of biogeochemical cycling. Copper is the element whose dissolved phase has the highest importance in metal transport across the salinity gradient. Results of speciation analysis demonstrate that the presence of excess amounts (5-8 fold) of unbound ligands confers a buffering capacity for potential inputs of dissolved metals into the Northern Adriatic Sea. The speciation of both copper and zinc in the dissolved phase was dominated by organic complexation. 相似文献