检索结果-南通市图书馆

Chinese Journal of Chemistry 2012年第3期30卷 656-664页

作者：辛杨皮子凤宋凤瑞刘志强刘淑莹 Changchun Center of mass spectrometry Changchun Institute of Applied ChemistryChinese Academy of Sciences5625 Renmin StreetChangchunJilin 130022China Graduate School of the Chinese Academy of Sciences Beijing 100039China

The extract of Radix aconiti was incubated with rat intestinal bacteria in vitro. Further, aconitine and hypaconitine standard were incubated at the same condition as the extract of Radix aconiti, respectively. Ultra Performance Liquid Chromatography/Multi-mass spectrometry （UPLC/MSn） was used for detecting and identifying all the aco- nite alkaloids. Results showed that there were four metabolites which were identified as 8-butyryl-14-benzoylmesa- conine （m/z 660）, 8-propionyl-14-benzoylaconine （m/z 660）, 8-butyryl-14-benzoylaconine （m/z 674） and 8-valeryl-14-benzoylmesaconine （m/z 674） in the metabolized sample of the extract of Radix aconiti. The relative area ratio of them presented increasing trend during 6 d. On the basis of all results, we could concluded that substi- tution at N atom mainly influenced the metabolizing rate of diester-diterpenoid alkaloids （DDAs）, C-8 substitute was active metabolized site, intestinal bacterial metabolites of the aconite alkaloids in the extract of Radix aconiti were mainly the substitute with propionyl group, butyl group or valeryl group at C-8. This paper illustrated holistic metabolizing profile of the extract of Radix aconiti in vitro and possible metabolizing reaction type of main DDAs, which could provide reference for finding out potential bioactive components in the extract and the prescription of Chinese Medicine.

关键词： Radix aconiti alkaloids intestinal bacteria liquid chromatography-mass spectrometry

EXPERIMENTAL STUDY ON THE IONIZATION AND DESORPTION REGION OF DESORPTION ATMOSPHERIC PRESSURE CHEMISTRY IONIZATION

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

EXPERIMENTAL STUDY ON THE IONIZATION AND DESORPTION REGION O...

Proteogenomic review of the changes in primate apoC-I during evolution

第十四届北京分析测试学术报告会暨展览会(BCEIA 2011)

作者： Feng HONG Bin JIA Yongzhong OUYANG Nannan WANG Huanwen CHEN Jiangxi Key laboratory for mass spectrometry and Instrumentation East China Institute of Technology

Desorption atmospheric pressure chemical ionization(DAPCI)has recently attracted increased attentions for its high sensitivity in the analysis of compounds of weak and *** this study,the PH test paper was used for det...

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Frontiers in Biology 2013年第5期8卷 533-548页

作者： Donald L. PUPPIONE Julian P. WHITELEGGE The Molecular Biology Institute University of California Los Angeles CA 90095 USA The Pasarow mass spectrometry laboratory The Jane & Terry Semel Institute for Neuroscience and Human Behavior David Geffen School of Medicine University of California Los Angeles CA 90095 USA

Apolipoprotein C-I has evolved more rapidly than any of the other soluble apolipoproteins. During the course of primate evolution, the gene for this apolipoprotein was duplicated. Prompted by our observation that the two resulting genes encode two distinct forms of apoC-I in great apes, we have reviewed both the genomic and proteomic data to examine what changes have occurred during the course of primate evolution. We have found data showing that one of the duplicated genes, known to be a pseudogene in humans, was also a pseudogene in Denisovans and Neandertals. Using genomic and proteomic data for primates, we will provide in this review evidence that the duplication took place after the divergence of New World monkeys from the human lineage and that the formation of the pseudogene took place after the divergence of the bonobos and chimpanzees from the human lineage.

关键词： mass spectrometry apoC-IA apoC-IB apes Old World monkeys New World monkeys

APPLICATIONS AND MECHANISMS OF EXTRACTIVE ELECTROSPRAY IONIZATION

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

APPLICATIONS AND MECHANISMS OF EXTRACTIVE ELECTROSPRAY IONIZ...

Vacuum promoted on-tissue derivatization strategy: Unravelling spatial distribution of glycerides on tissue

第十四届北京分析测试学术报告会暨展览会(BCEIA 2011)

作者： Huanwen CHEN Jiangxi Key laboratory for mass spectrometry and Instrumentation East China Institute of Technology

In extractive electrospray ionization(EESI),neutral samples with complex matrices(e.g.,urine,liquid milk,etc.)are directly nebulized to produce a sample plume,which is impacted by a primary ion beam created using an e...

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第12期35卷 503-509页

作者： Yu-Qi Cao Ying-Jie Lu Li Zhang Jing Zhang Yin-Long Guo State Key laboratory of Organometallic Chemistry and National Center for Organic mass spectrometry in Shanghai Center for Excellence in Molecular SynthesisShanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesChinese Academy of Sciences Technical Centre Shanghai Tobacco (Group) Corp. Department of Pharmacognosy School of PharmacyNaval Medical University

Matrix-assisted laser desorption ionization-mass spectrometry imaging (MALDI-MSI) has shown its capability in visualizing the spatial distribution of various kinds of endogenous ***,high quality mass imaging of low polar metabolites remains ***,a platform for sensitive matrix-assisted laser desorption ionization-mass spectrometry imaging of cholesterol and glycerides has been *** the platform,a vacuum promoted on-tissue derivatization strategy was proposed to constantly make the derivatization reaction proceed towards to the direction of *** with traditional on-tissue derivatization procedure,the strategy improved the acquired intensity of derivatized glycerides about 50%.Additionally,the mass spectrometry image reflecting the signal ratio between 3classes of glycerides was achieved to exploit the metabolic level of glycerides on tissue ***,the platform was applied to brain slices of Alzheimer’s transgenic mice,type 2 diabetes mice and normal *** difference was found in mass spectrometry images reflecting the signal ratio of multiple endogenous *** work constructed a promising platform for mapping of glycerides in tissue by mass spectrometry imaging.

关键词： mass spectrometry imaging On-tissue Derivatization Glycerides Alzheimer's disease

Overproduction of Alkaloid Phytoalexins in California Poppy Cells Is Associated with the Co-Expression of Biosynthetic and Stress-Protective Enzymes

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Molecular Plant 2010年第5期3卷 927-939页

作者： Sornitza Angelova Marcus Buchheim Doreen Frowitter Angelika Schierhorn Werner Roos Kliment-Ohridski-University of Sofia Faculty of Biology Institute of Molecular Biology Sofia Bulgaria Martin-Luther-University of Halle-Wittenberg institute of Pharmacy Department of Pharmaceutical Biology and Pharmacology Laboratory of Molecular Cell Biology Kurt Mothes Str. 3 06120 Halle (Saale) Germany Max-Planck-Research Group 'Enzymatics of Protein Folding' Laboratory of Mass Spectrometry Halle (Saale) Germany

Many plant cells respond to pathogens by the induction of phytoalexin biosynthesis, but the underlying changes of gene expression are often obscured by their close linkage to the complex rearrangements during pathogen defense, especially the hypersensitive cell death. In root-derived cell cultures of Eschscholzia californica, the overproduction of cytotoxic benzophenanthridine alkaloids can be triggered by a minimum of pathogen pressure that does not evoke hypersensitive reactions. Such conditions activate a signal chain that is initiated by a short contact to low concentrations of yeast glycoprotein elicitor and includes a transient acidification of the cytoplasm. In contrast, high elicitor concentrations signal via an increase of jasmonate and trigger hypersensitive cell death, preceded by a drastic decay of translatable mRNAs. The main changes in protein and mRNA patterns caused by either signal path were compared by 2D proteomic separation, MS/MS sequencing and mRNA-in vitro translation. The four proteins showing the highest overexpression were identical between cells that received low or high-elicitor treatment and overlapped with the three proteins most upregulated by artificial pH shifts. They comprised one biosynthetic enzyme （norcoclaurine：SAM 4＇ O-methyl-transferase） plus a unique combination of stress-protective proteins： a heat shock protein （hsp 70）; a peptidyl-prolyl-cis/trans isomerase （cyclophilin）; and a glyceraldehyde-3-phosphate dehydrogenase. It appears that overproduction of the benzophenanthri- dine phytoalexins requires the up-regulation of a rate-limiting biosynthetic enzyme plus the coordinated expression of a specific set of protective enzymes and thus is managed like an oxidative stress.

关键词： Benzophenanthridine alkaloid biosynthesis signal transduction stress protection functional proteomics pH signaling.

Resolving impact volatilization and condensation from target rock mixing and hydrothermal overprinting within the Chicxulub impact structure

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Geoscience Frontiers 2022年第5期13卷 16-31页

作者： Thomas Déhais Stepan M.Chernonozhkin Pim Kaskes Sietze J.de Graaff Vinciane Debaille Frank Vanhaecke Philippe Claeys Steven Goderis Analytical Environmental and Geo-ChemistryVrije Universiteit BrusselBrusselsBelgium Laboratoire G-Time UniversitécLibre de BruxellesBrusselsBelgium Department of Chemistry Atomic&Mass SpectrometryGhent UniversityGhentBelgium

This work presents isotopic data for the non-traditional isotope systems Fe,Cu,and Zn on a set of Chicxulub impactites and target lithologies with the aim of better documenting the dynamic processes taking place during hypervelocity impact events,as well as those affecting impact structures during the post-impact *** focus lies on material from the recent IODP-ICDP Expedition 364 Hole M0077A drill core obtained from the offshore Chicxulub peak *** ejecta blanket samples from the UNAM 5 and 7 cores were used to compare the crater lithologies with those outside of the impact *** datasets of bulk Fe,Cu,and Zn isotope ratios are coupled with petrographic observations and bulk major and trace element compositions to disentangle equilibrium isotope fractionation effects from kinetic *** observed Fe and Cu isotopic signatures,with δ^(56/54)Fe ranging from0.95‰to 0.58‰and δ^(65/63)Cu from0.73‰to 0.14‰,mostly reflect felsic,mafic,and carbonate target lithology mixing and secondary sulfide mineral formation,the latter associated to the extensive and long-lived(>105 years)hydrothermal system within Chicxulub *** the other hand,the stable Zn isotope ratios provide evidence for volatility-governed isotopic *** heavier Zn isotopic compositions observed for the uppermost part of the impactite sequence and a metamorphic clast(δ^(66/64)Zn of up to 0.80‰and 0.87‰,respectively)relative to most basement lithologies and impact melt rock units indicate partial vaporization of Zn,comparable to what has been observed for Cretaceous-Paleogene boundary layer sediments around the world,as well as for tektites from various strewn *** contrast to previous work,our data indicate that an isotopically light Zn reservoir(δ^(66/64)Zn down to0.49‰),of which the existence has previously been suggested based on mass balance considerations,may reside within the upper impact melt rock(UIM)*** observation is restricted to a few UIM sampl

关键词： Chicxulub impact structure Non-traditional stable isotopes Impact volatilization Impact condensation Hydrothermal alteration Target lithology mixing

维普期刊数据库

Post-Triassic thermal history of the Tazhong Uplift Zone in the Tarim Basin, Northwest China: Evidence from apatite fssion-track thermochronology

在线全文

学校读者我要写书评

暂无评论

Geoscience Frontiers 2013年第6期4卷 743-754页

作者： Caifu Xiang Xiongqi Pang Martin Daniík State Key laboratory for Petroleum Resource and Prospecting China University of Petroleum College of Geosciences China University of Petroleum John De Laeter Center of mass spectrometry Applied GeologyCurtin UniversityPerth 6152Australia Department of Earth and Ocean Sciences The University of WaikatoPrivate Bag 3105Hamilton 3240New Zealand

The Tarim Basin is a representative example of the basins developed in the northwest China that are characterized by multiple stages of heating and *** order to better understand its complex thermal history,apatite fission track （AFT） thermochronology was applied to borehole samples from the Tazhong Uplift Zone （TUZ）.Twelve sedimentary samples of Silurian to Triassic depositional ages were analyzed from depths coinciding with the apatite partial annealing zone （～60-120 ℃）.The AFT ages,ranging from 132 ± 7 Ma （from a Triassic sample） to 25 ± 2 Ma （from a Carboniferous sample）,are clearly younger than their depositional ages and demonstrate a total resetting of the AFT thermometer after *** AFT ages vary among different tectonic belts and decrease from the *** Faulted Zone （133-105 Ma） in the northwest,the Central Horst Zone in the middle （108-37 Ma）,to the East Buried Hill Zone in the south （51 25 Ma）.Given the low magnitude of post-Triassic burial heating evidenced by low vitrinite reflectance values （Ro ＜ 0.7％）,the total resetting of the AFT system is speculated to result from the hot fluid flow along the *** effects along the faults are well documented by younger AFT ages and unimodal single grain age distributions in the vicinity of the ***-early Triassic basaltic volcanism may be responsible for the early Triassic total annealing of those samples lacking connectivity with the *** above arguments are supported by thermal modeling results.

关键词： Apatite fission track Thermochronology Tectonics Fluid flow Tazhong Uplift Zone Tarim Basin

维普期刊数据库

Comprehensive Assessment of the Safety of Eucommia ulmoides Leaf Extract for Consumption as a Traditional Chinese Health Food

在线全文

学校读者我要写书评

暂无评论

Journal of Renewable Materials 2023年第7期11卷 3091-3114页

作者： Huiling Fu Mijun Peng Qiuwen Tang Haojun Liang Yanli Liang Jiali Fang Xuesong Wang School of Chemical and Environmental Engineering Hunan Institute of TechnologyHengyang421002China Guangdong Provincial Key laboratory of Chemical Measurement and Emergency Test Technology Guangdong Provincial Engineering Research Center for Ambient Mass SpectrometryInstitute of AnalysisGuangdong Academy of Sciences(China National Analytical CenterGuangzhou)Guangzhou510070China

To ensure the export quality of Eucommia ulmoides leaf extract(ELE)and facilitate *** leaf inclusion in the directory of traditional Chinese health foods,an overall safety assessment of ELE was performed,including genotoxicity and long-term toxicity,according to the national food safety standards of *** variations in the reverse mutation number of the nominal bacterial strains were observed under ELE treatment in comparison with the solvent ***,the micronucleus rates of in vivo mammalian erythrocytes and in vitro mammalian cells under ELE treatment were equivalent to or significantly lower than those of the solvent *** fold change in the trifluorothymidine resistance mutation frequency of the thymidine kinase gene under ELE treatment was less than three times in comparison with the solvent control,suggesting that ELE did not cause ***,animal experiments showed that the growth performance of rats under ELE treatment was enhanced because the body weights of rats *** oxidative injury or inflammatory responses were induced and no histopathological lesions of tissues were detected under ELE *** addition,plasma triglycerides and low-density lipoprotein cholesterol levels significantly decreased,and plasma high-density lipoprotein cholesterol levels significantly increased with ELE treatment,suggesting that ELE was ***,moderate to excellent antimicrobial activities,a favorable anticancer capacity,and superior antioxidant abilities of ELE were found,implying ELE possesses good ***,we affirmed ELE is safe to consume as a traditional Chinese health food.

关键词： Eucommia ulmoides leaf extract genotoxicity long-term toxicity growth performance bioactivity

Isolation and Purification of Plantamajoside and Acteoside from Plant Extract of Plantago asiatica L. by high Performance Centrifugal Partition Chromatography

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2009年第6期25卷 817-821页

作者： LI Li LIU Chun-ming CHEN Zhao-jie WANG Jing SHI Dong-fang LIU Zhi-qiang The Central laboratory Changchun Normal University Changchun 130032 P. R. China laboratory of New Drug Research and mass spectrometry Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun 130021 P. R. China Department of Endocrinology of China-Japan Union Hospital Jilin University Changchun 130033 P. R. China

Two phenylethanoid glycosides（PhGs）, plantamajoside and acteoside, were isolated and purified from the aerial parts ofPlantago asiatica for the first time by high performance centrifugal partition chromatography（HPCPC） with ethyl acetate, n-butanol, ethanol and water（0.5：0.5：0.1：1, volume ratio） as solvent system. A total of 45.6 mg of plantamajoside and 293.8 mg of acteoside were purified from 1341 mg of the n-butanol extract of P. asiatica, with a purity of 〉93.3% as determined by HPLC. The HPCPC fractions were analyzed by HPLC-DAD and the structures were identified by their retention time, UV, electrospray ionization multi stage tandem mass spectrometry（ESI-MSn） in the negative ion mode, and confirmed by NMR experiments. The characteristic fragment ions of ESI-MS of the two PhGs isolated from Plantago asiatica were discussed, which are specific and useful for the identification of the structures of PhGs.

关键词： Plantago asiatica L Plantamajoside Acteoside HPCPC ESI-MS HPLC-DAD

维普期刊数据库