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871.
872.
Miriam Altstein Orna Ben Aziz Alisa Bronshtein Jeanette M. Van Emon 《Analytica chimica acta》2010,675(2):138-147
Two polychlorinated biphenyls (PCB) enzyme linked immunosorbent assays (ELISAs) were developed using goat PCB purified immunoglobulin (IgG) antibodies (Abs). The IgGs exhibited the highest affinity toward PCB-77 (24 ng mL−1) with sensitivities in the range of 6-11 ng mL−1. The Abs cross-reacted with PCB-126 and the heptachlorodibenzofuran 1,2,3,4,6,7,8-HpCDF but not with PCB-169, PCB-118, Aroclor 1232, 1248, 1260 or the hexachlorodibenzofuran 2,3,4,6,7,8-HxCDF. The IgGs were also used to develop a sol-gel-based immunoaffinity purification (IAP) method for cleanup of PCB-126. Recovery efficiencies depended on the sol-gel formats; a 1:12 format resulted in the highest binding capacity. Net binding capacity ranged from 112 to 257 ng, and 90% of the analyte could be eluted with only 2 mL of ethanol. The method was also very efficient in purifying PCB-126 from spiked soil and sediment samples from contaminated sites; and eliminating matrix interferences to a degree that enabled analysis of the purified samples by ELISA. The approaches developed in the course of the study form a basis for the development of additional IAP methods for other PCBs, and their implementation in high-throughput screening programs for PCB in food, soil, and other environmental and biological samples. 相似文献
873.
Vladimíra Tomečková Alena Gajová Beáta Veliká Zuzana Šteffeková Lucia Lichardusová 《光谱学快报》2013,46(2):122-127
Paracetamol interaction with rat liver mitochondria in respiration media in the presence of succinate was the focus of this experiment. Fluorescence of paracetamol in water was studied by three-dimensional synchronous fluorescence fingerprint (SFF) and by excitation emission matrix (EEM). The direct molecular interactions of paracetamol and mitochondria were studied by fluorescence polarization technique. The paracetamol fluorescence maximum of SFF was Δλ = 110/λex = 320 nm, Fmax = 508 nm, and EEM maximum was λex = (320 nm)/λem = 425 nm, Fmax = 508. The fluorescence polarization results showed nonsignificant elevation of fluorescence polarization after addition of paracetamol into mitochondria in comparison to the control mitochondria group without paracetamol at time point t = 0. Paracetamol probably covalently bound to the mitochondrial surface proteins at time point t = 0, but paracetamol also entered mitochondria, which was observed as nonsignificant decline of fluorescence polarization during 30 min in the paracetamol-treated group. The practical advantages of spectral techniques (EEM, SFF, fluorescence polarization) are high sensitivity, reproducibility, minimal quantity of material, and capability to measure the mitochondrial autofluorescence. 相似文献
874.
875.
Melagraki G Afantitis A Sarimveis H Igglessi-Markopoulou O Alexandridis A 《Molecular diversity》2006,10(2):213-221
Summary This work introduces a neural network methodology for developing QSTR predictors of toxicity to Vibrio fischeri. The method adopts the Radial Basis Function (RBF) architecture and the fuzzy means training strategy, which is fast and repetitive,
in contrast to most traditional training techniques. The data set that was utilized consisted of 39 organic compounds and
their corresponding toxicity values to Vibrio fischeri, while lipophilicity, equalized electronegativity and one topological index were used to provide input information to the
models. The performance and predictive ability of the RBF model were illustrated through external validation and various statistical
tests. The proposed methodology can be used to successfully model toxicity to Vibrio fischerifor a heterogeneous set of compounds. 相似文献
876.
Sanctolide A (1), a 14-membered polyketide-nonribosomal peptide (PK-NRP) hybrid macrolide, was isolated from the cultured cyanobacterium Oscillatoria sancta (SAG 74.79). The planar structure was determined using various spectroscopic techniques including HRESIMS, and 1D and 2D NMR analyses. The relative configuration was assigned by J-based configurational analysis in combination with NOE correlations. The absolute configuration was determined by Mosher ester and enantioselective HPLC analyses. The structure of sanctolide A (1) features a rare N-methyl enamide and a 2-hydroxyisovaleric acid, which are incorporated to form a 14-membered macrolide ring structure, comprising a new type of cyanobacterial macrolides derived from a PKS-NRPS hybrid biosynthetic pathway. 相似文献
877.
Adamantios Krokos Olga Deda Christina Virgiliou Helen Gika Nikolaos Raikos Eleni Aggelidou Aristeidis Kritis Georgios Theodoridis 《Molecules (Basel, Switzerland)》2021,26(15)
Cocaine toxicity has been a subject of study because cocaine is one of the most common and potent drugs of abuse. In the current study the effect of cocaine on human liver cancer cell line (HepG2) was assessed. Cocaine toxicity (IC50) on HepG2 cells was experimentally calculated using an XTT assay at 2.428 mM. The metabolic profile of HepG2 cells was further evaluated to investigate the cytotoxic activity of cocaine at 2 mM at three different time points. Cell medium and intracellular material samples were analyzed with a validated HILIC-MS/MS method for targeted metabolomics on an ACQUITY Amide column in gradient mode with detection on a triple quadrupole mass spectrometer in multiple reaction monitoring. About 106 hydrophilic metabolites from different metabolic pathways were monitored. Multivariate analysis clearly separated the studied groups (cocaine-treated and control samples) and revealed potential biomarkers in the extracellular and intracellular samples. A predominant effect of cocaine administration on alanine, aspartate, and glutamate metabolic pathway was observed. Moreover, taurine and hypotaurine metabolism were found to be affected in cocaine-treated cells. Targeted metabolomics managed to reveal metabolic changes upon cocaine administration, however deciphering the exact cocaine cytotoxic mechanism is still challenging. 相似文献
878.
The oral acute toxicity for tri-n-butyltin glycocholate (TBT-GA), a newly synthesized organotin steroid, was determined using Long Evans rats. The compound was suspended in corn oil and adminstered by gavage using standard techniques. Unlike tri-n-butyltin taurocholate, which exhibited two different toxicities, one for the tri-n-butyltin moiety and one for the taurocholic acid moiety, the TBT-GA exhibited a single toxicity, that of the whole molecule. The LD50 value was 213 mg kg?1 (0.274 mmol kg), which on a millimolar basis is similar to that observed for other tri-n-butyltin compounds. The dead rats exhibited distended stomachs, enlarged ceca, and lesions in the intestinal tract. The actual cause of death could not be positively identified. Animals that survived more than three days also exhibited time- and dose-related atrophy of the thymus gland. With 36% more male than female rats succumbing to TBT-GA, the chemical appears to be more toxic towards male than female rats. 相似文献
879.
Metal Sulfide Cluster Complexes and their Biogeochemical Importance
in the Environment 总被引:1,自引:0,他引:1
Aqueous clusters of FeS, ZnS and CuS constitute a major fraction of the dissolved metal load in anoxic oceanic, sedimentary,
freshwater and deep ocean vent environments. Their ubiquity explains how metals are transported in anoxic environmental systems.
Thermodynamic and kinetic considerations show that they have high stability in oxic aqueous environments, and are also a significant
fraction of the total metal load in oxic river waters. Molecular modeling indicates that the clusters are very similar to
the basic structural elements of the first condensed phase forming from aqueous solutions in the Fe–S, Zn–S and Cu–S systems.
The structure of the first condensed phase is determined by the structure of the cluster in solution. This provides an alternative
explanation of Ostwald’s Rule, where the most soluble, metastable phases form before the stable phases. For example, in the
case of FeS, we showed that the first condensed phase is nanoparticulate, metastable mackinawite with a particle size of 2 nm
consisting of about 150 FeS subunits, representing the end of a continuum between aqueous FeS clusters and condensed material.
These metal sulfide clusters and nanoparticles are significant in biogeochemistry. Metal sulfide clusters reduce sulfide and
metal toxicity and help drive ecology. FeS cluster formation drives vent ecology and AgS cluster formation detoxifies Ag in
Daphnia magna neonates. We also note a new reaction between FeS and DNA and discuss the potential role of FeS clusters in denaturing DNA.
An erratum to this article is available at . 相似文献
880.