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Chromatography

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https://www.readbyqxmd.com/read/27936405/identification-of-lipopolysaccharide-interacting-plasma-membrane-type-proteins-in-arabidopsis-thaliana
#1
Cornelius S Vilakazi, Ian A Dubery, Lizelle A Piater
Lipopolysaccharide (LPS) is an amphiphatic bacterial glycoconjugate found on the external membrane of Gram-negative bacteria. This endotoxin is considered as a microbe-associated molecular pattern (MAMP) molecule and has been shown to elicit defense responses in plants. Here, LPS-interacting proteins from Arabidopsis thaliana plasma membrane (PM)-type fractions were captured and identified in order to investigate those involved in LPS perception and linked to triggering of innate immune responses. A novel proteomics-based affinity-capture strategy coupled to liquid chromatography-tandem mass spectrometry (LC-MS/MS) was employed for the enrichment and identification of LPS-interacting proteins...
November 30, 2016: Plant Physiology and Biochemistry: PPB
https://www.readbyqxmd.com/read/27936316/bioprospecting-of-turbinaria-macroalgae-as-a-potential-source-of-health-protective-compounds
#2
Milena Stranska-Zachariasova, Isma Kurniatanty, Helena Gbelcova, Monika Jiru, Josep Rubert, Tjokorda Gde Tirta Nindhia, Cosimo Walter D'Acunto, Sony Heru Sumarsono, Marselina Irasonia Tan, Jana Hajslova, Tomas Ruml
The present study aims to focus on the bioprospecting of marine macroalgae of Turbinaria species, plenteous biomass of the world ocean. Three types of solvents, i.e. water, methanol:water (80:20, v/v) and hexane:isopropanol (50:50, v/v), were used for extraction. Both the biological activity, as well as the pattern of present chemicals were characterized. For the cell proliferation assay, the human embryonic kidney 293 cells, cervix / breast / pancreatic adenocarcinoma, and osteosarcoma cells were used. For the antioxidant activity determination, both intracellular assay with human embryonic kidney and cervix adenocarcinoma cells, as well as the biochemical DPPH test, were employed...
December 9, 2016: Chemistry & Biodiversity
https://www.readbyqxmd.com/read/27936100/a-high-resolution-crystal-structure-of-a-psychrohalophilic-%C3%AE-carbonic-anhydrase-from-photobacterium-profundum-reveals-a-unique-dimer-interface
#3
Vijayakumar Somalinga, Greg Buhrman, Ashikha Arun, Robert B Rose, Amy M Grunden
Bacterial α-carbonic anhydrases (α-CA) are zinc containing metalloenzymes that catalyze the rapid interconversion of CO2 to bicarbonate and a proton. We report the first crystal structure of a pyschrohalophilic α-CA from a deep-sea bacterium, Photobacterium profundum. Size exclusion chromatography of the purified P. profundum α-CA (PprCA) reveals that the protein is a heterogeneous mix of monomers and dimers. Furthermore, an "in-gel" carbonic anhydrase activity assay, also known as protonography, revealed two distinct bands corresponding to monomeric and dimeric forms of PprCA that are catalytically active...
2016: PloS One
https://www.readbyqxmd.com/read/27936051/forsythia-suspensa-suppresses-house-dust-mite-extract-induced-atopic-dermatitis-in-nc-nga-mice
#4
Yoon-Young Sung, Taesook Yoon, Seol Jang, Ho Kyoung Kim
Forsythia suspensa (F. suspensa) is a traditional medicine for treatment of inflammation. In this study, we evaluated the therapeutic effects of an ethanol extract from F. suspensa fruits on atopic dermatitis both in vivo and in vitro. We investigated the inhibitory effects of F. suspensa extract on the development of atopic dermatitis-like skin lesions in an NC/Nga mouse model exposed to Dermatophagoides farinae crude extract. Topical application of F. suspensa extract to the mice attenuated the atopic dermatitis symptoms, including increased dermatitis severity score, ear thickness, infiltration of inflammatory cells in the skin lesions, serum levels of IgE, TNF-α, and histamine, and expression of chemokines, cytokines, and adhesion molecules in ear tissue...
2016: PloS One
https://www.readbyqxmd.com/read/27936013/%C3%AE-asarone-rescues-pb-induced-impairments-of-spatial-memory-and-synaptogenesis-in-rats
#5
Qian-Qian Yang, Wei-Zhen Xue, Rong-Xin Zou, Yi Xu, Yang Du, Shuang Wang, Lai Xu, Yuan-Zhi Chen, Hui-Li Wang, Xiang-Tao Chen
Chronic lead (Pb) exposure causes cognitive deficits. This study aimed to explore the neuroprotective effect and mechanism of β-asarone, an active component from Chinese Herbs Acorus tatarinowii Schott, to alleviate impairments of spatial memory and synaptogenesis in Pb-exposed rats. Both Sprague-Dawley developmental rat pups and adult rats were used in the study. Developmental rat pups were exposed to Pb throughout the lactation period and β-asarone (10, 40mg kg-1, respectively) was given intraperitoneally from postnatal day 14 to 21...
2016: PloS One
https://www.readbyqxmd.com/read/27935671/two-dimensional-liquid-chromatography-a-state-of-the-art-tutorial
#6
Dwight R Stoll, Peter W Carr
In this tutorial, we discuss the motivations for doing two-dimensional liquid chromatography (2D-LC) and describe the commonly used implementations of the method. We review important guiding principles for method development, discuss the state of the art in 2D-LC performance as measured by peak capacity, and describe example applications from different fields that we hope will inspire new users to adopt 2D-LC for their analytical problems.
December 9, 2016: Analytical Chemistry
https://www.readbyqxmd.com/read/27935425/how-is-herstatin-a-tumour-suppressor-splice-variant-of-the-oncogene-her2-regulated
#7
Marco Silipo, Hannah Gautrey, Swapna Satam, Thomas Lennard, Alison Tyson-Capper
The human epidermal growth factor receptor 2 (HER2)/receptor tyrosine-protein kinasebB-2 (ERBB2) is over-expressed in 20-30% of breast tumours leading to faster growing and more aggressive tumours. Alternative splicing generates a functionally distinct HER2 variant called Herstatin, which is produced by the inclusion of intron 8. Herstatin acts as a tumour suppressor by effectively blocking HER2 activity and cell proliferation, while promoting apoptosis. In the present study we investigated HER2 pre-mRNA regulatory sequences and splicing factors which regulate the alternative splicing of Herstatin...
December 9, 2016: RNA Biology
https://www.readbyqxmd.com/read/27935281/engineering-cyclohexanone-monooxygenase-for-the-production-of-methyl-propanoate
#8
Hugo L van Beek, Elvira Romero, Marco W Fraaije
A previous study showed that cyclohexanone monooxygenase from Acinetobacter calcoaceticus (AcCHMO) catalyzes the Baeyer-Villiger oxidation of 2-butanone, yielding ethyl acetate and methyl propanoate as products. Methyl propanoate is of industrial interest as a precursor of acrylic plastic. Here, various residues near the substrate and NADP+ binding sites in AcCHMO were subjected to saturation mutagenesis to enhance both the activity on 2-butanone and the regioselectivity toward methyl propanoate. The resulting libraries were screened using whole cell biotransformations, and headspace gas chromatography-mass spectrometry was used to identify improved AcCHMO variants...
December 9, 2016: ACS Chemical Biology
https://www.readbyqxmd.com/read/27935260/in-vitro-studies-on-flubromazolam-metabolism-and-detection-of-its-metabolites-in-authentic-forensic-samples
#9
Carolina Noble, Marie Mardal, Niels Bjerre Holm, Sys Stybe Johansen, Kristian Linnet
Flubromazolam is a triazole benzodiazepine with high potency and long-lasting central nervous system depressant effects; however, limited data about its pharmacokinetics are available. Here, we report in vitro studies of the human flubromazolam metabolism analyzed by liquid chromatography high-resolution mass spectrometry (LC-HRMS). In vitro investigations were carried out in pooled human liver microsomes (pHLM) and recombinant cytochrome P450 (CYP)-enzymes. To confirm those metabolites detected in vitro, authentic samples obtained from two forensic cases were also analyzed by LC-HRMS...
December 9, 2016: Drug Testing and Analysis
https://www.readbyqxmd.com/read/27935254/application-of-solid-phase-microextraction-with-gas-chromatography-and-mass-spectrometry-for-the-early-detection-of-active-moulds-on-historical-woollen-objects
#10
Tomasz Sawoszczuk, Justyna Syguła-Cholewińska, Julio M Del Hoyo-Meléndez
The goal of this work was to determine the microbial volatile organic compounds emitted by moulds growing on wool in search of particular volatiles mentioned in the literature as indicators of active mould growth. The keratinolytically active fungi were inoculated on two types of media: (1) samples of wool placed on broths, and (2) on broths containing amino acids that are elements of the structure of keratin. All samples were prepared inside 20 mL vials (closed system). In the first case (1) the broths did not contain any sources of organic carbon, nitrogen, or sulfur i...
December 9, 2016: Journal of Separation Science
https://www.readbyqxmd.com/read/27935251/simultaneous-determination-of-35-ultra-trace-level-organophosphorus-pesticide-residues-in-sanjie-zhentong-capsules-of-traditional-chinese-medicine-using-ultra-high-performance-liquid-chromatography-with-tandem-mass-spectrometry
#11
Jiachun Li, Dongpo Li, Jingling Wu, Jianping Qin, Junhua Hu, Wenzhe Huang, Zhenzhong Wang, Wei Xiao, Yu Wang
The aim of this study was to develop an analytical method for the simultaneous determination of ultra-trace levels of 35 organophosphorus pesticide residues in Sanjie Zhentong capsules, a traditional Chinese medicine prescription. A method based on multiclass and multiresidue sample preparation was developed. First, samples were hydrated with water in 4°C. A ratio of 1:3 sample/water was used for each of the sample amounts. Then, different extraction solvents were screened. This step was followed by a dispersive solid-phase extraction clean-up procedure using both primary secondary amine and polyamide...
December 9, 2016: Journal of Separation Science
https://www.readbyqxmd.com/read/27935246/determination-of-a-metabolite-of-nifursol-in-foodstuffs-of-animal-origin-by-liquid-liquid-extraction-and-liquid-chromatography-with-tandem-mass-spectrometry
#12
Chuanxian Wang, Li Qu, Xia Liu, Chaomin Zhao, Fengjuan Zhao, Fuzhen Huang, Zhenou Zhu, Chao Han
An analytical method has been developed for the detection of a metabolite of nifursol, 3,5-dinitrosalicylic acid hydrazide, in foodstuffs of animal origin (chicken liver, pork liver, lobster, shrimp, eel, sausage and honey). The method combines liquid chromatography and tandem mass spectrometry with liquid-liquid extraction. Samples were hydrolyzed with hydrochloric acid and derivatized with 2-nitrobenzaldehyde at 37°C for 16 h. The solutions of derivatives were adjusted to pH 7.0-7.5, and the metabolite was extracted with ethyl acetate...
December 9, 2016: Journal of Separation Science
https://www.readbyqxmd.com/read/27935238/identification-of-novel-disulfide-adducts-between-the-thiol-containing-leaving-group-of-the-nerve-agent-vx-and-cysteine-containing-tripeptides-derived-from-human-serum-albumin
#13
Andreas Kranawetvogl, Jim Küppers, Michael Gütschow, Franz Worek, Horst Thiermann, Paul W Elsinghorst, Harald John
Chemical warfare agents represent a continuous and considerable threat to military personnel and the civilian population. Such compounds are prohibited by the Chemical Weapons Convention, to which adherence by the member states is strictly controlled. Therefore, reliable analytical methods for verification of an alleged use of banned substances are required. Accordingly, current research focuses on long-term biomarkers derived from covalent adducts with biomolecules such as proteins. Recently, we have introduced a microbore liquid chromatography/electrospray ionization high-resolution tandem mass spectrometry method allowing for the investigation of two different classes of adducts of the nerve agent VX with human serum albumin (HSA)...
December 9, 2016: Drug Testing and Analysis
https://www.readbyqxmd.com/read/27935227/preparative-isolation-of-bioactive-compounds-from-stem-bark-of-juglans-mandshurica-by-using-high-speed-counter-current-chromatography
#14
Yuwei Zhang, Hua Lin, Shanshan Li, Jianbo Chen, Yinshi Sun, Yuxin Li
High-speed counter-current chromatography was applied for the first time to the separation and purification of bioactive compounds contained in the stem bark of Juglans mandshurica Maxim. Silica gel column chromatography was first used to obtain three composition-enriched target fractions from a crude J. mandshurica methanol extract. Three independent high-speed counter-current chromatography processes were then used to further isolate 13 bioactive compounds, namely, six galloyl glucose derivatives, three flavonones, three naphthoquinones, and ethyl gallate...
December 9, 2016: Journal of Separation Science
https://www.readbyqxmd.com/read/27935213/uhplc-q-tof-ms-based-metabolomics-approach-to-compare-the-saponin-compositions-of-xueshuantong-injection-and-xuesaitong-injection
#15
Changliang Yao, Wenzhi Yang, Jingxian Zhang, Shi Qiu, Ming Chen, Xiaojian Shi, Huiqin Pan, Wanying Wu, Dean Guo
Various traditional Chinese medicine preparations developed from Notoginseng total saponins, including Xueshuantong Injection and Xuesaitong Injection, are extensively used in China to treat cardio-cerebrovascular diseases. However, the difference of their saponin compositions remains unknown. An ultra high performance liquid chromatography with quadrupole time-of-flight mass spectrometry based metabolomics approach was developed to probe the saponin discrimination between Xueshuantong and Xuesaitong and the related factors by large sample analysis...
December 9, 2016: Journal of Separation Science
https://www.readbyqxmd.com/read/27935189/epigenetic-regulation-of-the-glucose-transporter-gene-slc2a1-by-%C3%AE-hydroxybutyrate-underlies-preferential-glucose-supply-to-the-brain-of-fasted-mice
#16
Kosuke Tanegashima, Yukiko Sato-Miyata, Masabumi Funakoshi, Yasumasa Nishito, Toshiro Aigaki, Takahiko Hara
We carried out liquid chromatography-tandem mass spectrometry analysis of metabolites in mice. Those metabolome data showed that hepatic glucose content is reduced, but that brain glucose content is unaffected, during fasting, consistent with the priority given to brain glucose consumption during fasting. The molecular mechanisms for this preferential glucose supply to the brain are not fully understood. We also showed that the fasting-induced production of the ketone body β-hydroxybutyrate (β-OHB) enhances expression of the glucose transporter gene Slc2a1 (Glut1) via histone modification...
December 9, 2016: Genes to Cells: Devoted to Molecular & Cellular Mechanisms
https://www.readbyqxmd.com/read/27935159/de-novo-sequencing-of-highly-modified-therapeutic-oligonucleotides-by-hydrophobic-tag-sequencing-coupled-with-lc-ms
#17
Rieko Goto, Shin Miyakawa, Emire Inomata, Tomonori Takami, Junji Yamaura, Yoshikazu Nakamura
Correct sequences are prerequisite for quality control of therapeutic oligonucleotides. However, there is no definitive method available for determining sequences of highly modified therapeutic RNAs, and thereby most of the oligonucleotides have been used clinically without direct sequence determination. In this study, we developed a novel sequencing method called 'hydrophobic tag sequencing'. Highly modified oligonucleotides are sequenced by partially digesting oligonucleotides conjugated with a 5'-hydrophobic tag, followed by liquid chromatography-mass spectrometry analysis...
December 9, 2016: Journal of Mass Spectrometry: JMS
https://www.readbyqxmd.com/read/27935129/performance-comparison-of-esi-and-apci-in-untargeted-and-targeted-lc-ms-based-metabolomics-analysis-of-grapeberry-metabolites
#18
Mauro Commisso, Andrea Anesi, Silvia Dal Santo, Flavia Guzzo
RATIONALE: Electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) are both used to generate ions for the analysis of metabolites by liquid chromatography/mass spectrometry (LC-MS). We compared the performance of these methods for the analysis of Corvina grapevine berry methanolic extracts, which are complex mixtures of diverse metabolites. METHODS: Corvina berries representing three ripening stages (veraison, early-ripening and full-ripening) were collected during two growing seasons, powdered and extracted with methanol...
December 9, 2016: Rapid Communications in Mass Spectrometry: RCM
https://www.readbyqxmd.com/read/27934952/effect-of-arginine-on-oligomerization-and-stability-of-n-acetylglutamate-synthase
#19
N Haskins, A Mumo, P H Brown, M Tuchman, H Morizono, L Caldovic
N-acetylglutamate synthase (NAGS; E.C.2.3.1.1) catalyzes the formation of N-acetylglutamate (NAG) from acetyl coenzyme A and glutamate. In microorganisms and plants, NAG is the first intermediate of the L-arginine biosynthesis; in animals, NAG is an allosteric activator of carbamylphosphate synthetase I and III. In some bacteria bifunctional N-acetylglutamate synthase-kinase (NAGS-K) catalyzes the first two steps of L-arginine biosynthesis. L-arginine inhibits NAGS in bacteria, fungi, and plants and activates NAGS in mammals...
December 9, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27934920/functional-human-induced-hepatocytes-hiheps-with-bile-acid-synthesis-and-transport-capacities-a-novel-in-vitro-cholestatic-model
#20
Xuan Ni, Yimeng Gao, Zhitao Wu, Leilei Ma, Chen Chen, Le Wang, Yunfei Lin, Lijian Hui, Guoyu Pan
Drug-induced cholestasis is a leading cause of drug withdrawal. However, the use of primary human hepatocytes (PHHs), the gold standard for predicting cholestasis in vitro, is limited by their high cost and batch-to-batch variability. Mature hepatocyte characteristics have been observed in human induced hepatocytes (hiHeps) derived from human fibroblast transdifferentiation. Here, we evaluated whether hiHeps could biosynthesize and excrete bile acids (BAs) and their potential as PHH alternatives for cholestasis investigations...
December 9, 2016: Scientific Reports
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