• 제목/요약/키워드: electrospray ionization (ESI)

검색결과 186건 처리시간 0.019초

Lanostane Triterpenoids from Ganoderma tropicum Collected in Vietnam and Their Nitroblue Tetrazolium Reductive Activity In Vitro

  • Nguyen, Thi Duyen;Nguyen, Minh Khoi;Phan, Nguyen Truong Thang;Duong, Minh Tan;Tran, Viet Hung;Do, Thi Ha
    • Natural Product Sciences
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    • 제26권4호
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    • pp.334-339
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    • 2020
  • A new compound, 3��-acetoxylanosta-7,9(11),24-triene-26-al (3), and seven known compounds (1 - 2 and 4 - 8) were isolated from Ganoderma tropicum (Jung.) Bres. collected in Tay Nguyen, Vietnam. The structures of these compounds were determined by one- and two-dimensional nuclear magnetic resonance spectroscopy, electrospray ionization mass spectrometry (ESI-MS), and high-resolution ESI-MS, and by comparison with literature data. All of the isolated compounds were tested for nitroblue tetrazolium (NBT) reduction activity in Saccharomyces cerevisiae-stimulated RAW 246.7 cells. Among them, compounds 2 - 4 and 6 - 8 enhanced the NBT reduction in a dose-dependent manner.

Quantitative Proteomics Towards Understanding Life and Environment

  • Choi, Jong-Soon;Chung, Keun-Yook;Woo, Sun-Hee
    • 한국환경농학회지
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    • 제25권4호
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    • pp.371-381
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    • 2006
  • New proteomic techniques have been pioneered extensively in recent years, enabling the high-throughput and systematic analyses of cellular proteins in combination with bioinformatic tools. Furthermore, the development of such novel proteomic techniques facilitates the elucidation of the functions of proteins under stress or disease conditions, resulting in the discovery of biomarkers for responses to environmental stimuli. The ultimate objective of proteomics is targeted toward the entire proteome of life, subcellular localization biochemical activities, and the regulation thereof. Comprehensive analysis strategies of proteomics can be classified into three categories: (i) protein separation via 2-dimensional gel electrophoresis (2-DE) or liquid chromatography (LC), (ii) protein identification via either Edman sequencing or mass spectrometry (MS), and (iii) proteome quantitation. Currently, MS-based proteomics techniques have shifted from qualitative proteome analysis via 2-DE or 2D-LC coupled with off-line matrix assisted laser desorption ionization (MALDI) and on-line electrospray ionization (ESI) MS, respectively, toward quantitative proteome analysis. In vitro quantitative proteomic techniques include differential gel electrophoresis with fluorescence dyes. protein-labeling tagging with isotope-coded affinity tags, and peptide-labeling tagging with isobaric tags for relative and absolute quantitation. In addition, stable isotope-labeled amino acids can be in vivo labeled into live culture cells via metabolic incorporation. MS-based proteomics techniques extend to the detection of the phosphopeptide mapping of biologically crucial proteins, which ale associated with post-translational modification. These complementary proteomic techniques contribute to our current understanding of the manner in which life responds to differing environment.

HPLC/ESI/MS를 이용한 물 중의 알킬페놀에톡실레이트 분석 (Determination of alkylphenol ethoxylate in water by high performance liquid chromatography/electrospray ionization/mass spectrometry)

  • 이정애;박송자;정봉철
    • 분석과학
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    • 제17권3호
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    • pp.263-270
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    • 2004
  • 알킬페놀에톡실레이트 (APEO)는 주로 비이온성 계면활성제로 쓰이고 있으며 세제, 액체연료 및 농약에도 이용이 되고 있다. APEO 자체는 독성물질로 분류되어 있지 않지만, 그 대사생성물질인 단사슬 APEO, 알킬페놀 및 카르복실 유도체등은 폐수 또는 음용수를 염소처리하는 동안 mutagenic ring halogenated derivative를 생성한다. 이들 생성물들은 estrogenic effect를 나타내기 때문에 APEO를 제한 또는 규제하고 있는 추세이다. 본 연구에서는 APEO의 대사체로서 단사슬 APEO 인 4-nonylphenol-di-ethoxylate (NP2EO), 4-octylphenol-di-ethoxylate (OP2EO)를 분석하기 위해서 p-n-nonylphenol-di-ethoxylate-ring-$^{13}C_6$을 내부표준물질로 사용하여 HPLC/ESI/MS를 이용하여 분석하였다. 분석조건은 이온화 용매인 trifluoroacetic acid가 $10{\mu}M$이 되도록 각각 물과 메탄올에 첨가시켜 사용하였다. 물시료 1 L에 진한 황산을 이용하여 pH를 2이하로 조정한 후, 아세톤, 메탄올 및 물 (pH 2)로 활성화시킨 Sep-Pak $C_{18}$에 loading 시킨 후 아세톤으로 용출하여 시료용액으로 하였다. 이 방법으로 농도범위가 20 ~ 500 ng/L 내에서 검량선의 직선성은 r=0.999 (OP2EO)와 0.990 (NP2EO)였으며, 검출한계는 OP2EO는 20 ng/L, NP2EO는 50 ng/L 이었다. 정확도 및 정밀도는 85.8~122.1% 및 8.2~18.8 %로 좋은 결과를 나타냈다. 이 방법은 환경시료로부터 미량의 APEO를 분석하는데 사용될 수 있고, APEO 오염실태 조사에 응용될 수 있을 것으로 사료된다.

Toxicoproteomics in the Study of Aromatic Hydrocarbon Toxicity

  • Cho, Chang-Won;Kim, Chan-Wha
    • Biotechnology and Bioprocess Engineering:BBE
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    • 제11권3호
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    • pp.187-198
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    • 2006
  • The aromatic hydrocarbons (AHs), which include benzene, polycyclic aromatic hydrocarbons, and dioxin, are important chemical and environmental contaminants in industry that usually cause various diseases. Over the years, numerous studies have described and evaluated the adverse health effects induced by AHs. Currently, "Omics" technologies, transcriptomics and proteomics, have been applied in AH toxicity studies. Proteomics has been used to identify molecular mechanisms and biomarkers associated with global chemical toxicity. It could enhance our ability to characterize chemical-induced toxicities and to identify noninvasive biomarkers. The proteomic approach (e.g. 2-dimensional electrophoresis [2-DE]), can be used to observe changes in protein expression during chemical exposure with high sensitivity and specificity. Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) and electrospray ionization-quadrupole (ESI-Q)-TOF MS/MS are recognized as the most important protein identification tools. This review describes proteomic technologies and their application in the proteomic analysis of AH toxicity.

Identification of Nandrolone and its Metabolite 5α-Estran-3β, 17α-Diol in Horse Urine after Chemical Derivatization by Liquid Chromatography Tandem Mass Spectrometry

  • Dubey, Saurabh;Beotra, Alka
    • Mass Spectrometry Letters
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    • 제8권4호
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    • pp.90-97
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    • 2017
  • Androgenic anabolic steroids (AASs) are synthetic derivatives of testosterone with a common structure containing cyclopentanoperhydrophenanthrene nucleus. Their use enhances the muscle building capacity and is beneficial during performance. The AASs are one of the most abused group of substances in horse doping. Liquid chromatography tandem mass spectrometry ($LC/MS^n$) has been successfully applied to the detection of anabolic steroids in biological samples. However, the saturated hydroxysteroids viz: nandrolone, $5{\alpha}-estrane-3{\beta}$, $17{\alpha}-diol$ exhibit lower detection responses in electrospray ionisation (ESI) because of their poor ionisation efficiency. To overcome this limitation pre-column chemical derivatization has been introduced to enhance their detection responses in $LC-ESI-MS^n$ analysis. The aim of present study was to develop a sensitive method for identification and confirmation of nandrolone and its metabolite in horse urine incorporating pre-column derivatization using picolinic acid. The method consists of extraction of targeted steroid conjugates by solid phase extraction (SPE). The eluted steroid conjugates were hydrolysed by methanolysis and free steroids were recovered with liquid-liquid extraction. The resulting steroids were derivatized to form picolinoyl esters and identification was done using LC-ESI-MS/MS in positive ionization mode. The picolinated steroid adduct enhanced the detection levels in comparison to underivatized steroids.

Quantitative and Qualitative Analysis of Alkaloids in Coptis chinensis (Coptidis Rhizoma) by LC-DAD and LC-ESI/MS

  • Yu, Young-Beob;Bae, Chang-Hyu
    • 한국자원식물학회지
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    • 제30권6호
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    • pp.693-698
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    • 2017
  • The quality control of natural products is principal key to guarantee the Good Manufacturing Practices (GMP) and Good Clinical Practices (GCP) for the functional food, pharmaceuticals and cosmeceuticals in the industry. In this study, we examined the quantitative analysis of berberine as marker substance of Coptidis Rhizoma by high performance liquid chromatography-photodiode array detector (HPLC-DAD). The HPLC method was validated and met all the requirements for the quality control analysis recommended by FDA and ICH. The berberine was separated on a Xterra $C_{18}$ column ($5{\mu}m$, $4.6{\times}250mm$) using mobile phase consisting of distilled water and acetonitrile with $KH_2PO_4$ (3.4 g) and $Na_2SO_4$ (1.7 g). Calibration curve of berberine has been estimated (y = 42293.47x-41589 with the correlation coefficient 0.9999). The amount of berberine was calculated as 4.25%. And berberastine, palmatine, columbamine, jatrorrhizine, epiberberine, berberine and coptisine in the Coptidis Rhizoma were identified by high performance liquid chromatography - electrospray ionization-mass spectrometer (HPLC-ESI-MS) method.

Molecular Simulations and Conformational Studies of Fucoseα1-3)Gal(β1-X)GlcNAc where X=3, 4, or 6 Oligosaccharides

  • Yoo, Eun-Sun;Yoon, In-Mo
    • Bulletin of the Korean Chemical Society
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    • 제29권9호
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    • pp.1755-1760
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    • 2008
  • Energy minimization and conformational studies of molecular ions generated by ESI (electrospray ionization) tandem mass spectrometry (MS/MS) can be used for the discrimination of stereoisomeric permethylated and sodium cationized trisaccharides. Sets of fucose-containing trisaccharides having different internal and terminal linkages have been synthesized to analyze the reducing terminal linkage positions using BT and IT fusion approaches. A detailed investigation has been undertaken on the conformational behaviors of four trisaccharide fragments from human milk and blood group determinants of Type 1 and Type 2, namely Fuc($\alpha$1- 3)Gal($\beta$1-3)GalNAc and Fuc($\alpha$1-3)Gal($\beta$1-X)GlcNAc where X = 3, 4 and 6 using molecular modeling methods. Three dimensional rigid and adiabatic phi-psi-energy maps (Surfer program) describing the energy as a function of rotation around corresponding glycosidic linkages were calculated by SYBYL molecular modeling and MM4 force field programs conjunction with cleavage energies of ESI MS/MS for the side group orientations. This approach predicted conformational behaviors exhibited by isomer saccharides for future applications on biologically active glycoconjugates and to exploit a faster method of synthesizing a series of structural isomeric oligosaccharides.

금강 지표수에서 LC-ESI-MS/MS에 의한 염소산이온의 극미량 분석 (Determination of perchlorate in the Gum-River surface water by LC-ESI-MS/MS)

  • 이영준;이준배;홍선화;김현지;신호상
    • 분석과학
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    • 제25권6호
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    • pp.435-440
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    • 2012
  • 지표수 중에 과염소산이온을 LC-ESI-MS/MS을 사용하여 분석하였다. 시료는 단지 PTFE 필터를 사용하여 거른 후 LC-ESI-MS/MS 시스템에 직접 주입하여 분석하였다. 이 방법은 3% 이내의 정밀도를 보였고 정량한계는 0.17 ${\mu}g/L$이었다. 시료는 금강물 35 개 유역에서 2, 4, 6월에 각각 시료를 채취하였다. 그 결과 일반 하천수에서는 과염소산이온이 0.23-3.73 ${\mu}g/L$ (평균 0.20 ${\mu}g/L$) 농도범위로 15% 빈도로 검출되었고 공단 근처의 지표수에서는 0.36-25.10 ${\mu}g/L$ (평균 1.69 ${\mu}g/L$)로 36%의 빈도로 검출되었다.

Quantitative Evaluation of Radix Astragali through the Simultaneous Determination of Bioactive Isoflavonoids and Saponins by HPLC/UV and LC-ESI-MS/MS

  • Kim, Jin-Hee;Park, So-Young;Lim, Hyun-Kyun;Park, Ah-Yeon;Kim, Ju-Sun;Kang, Sam-Sik;Youm, Jeong-Rok;Han, Sang-Beom
    • Bulletin of the Korean Chemical Society
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    • 제28권7호
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    • pp.1187-1194
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    • 2007
  • The three major active isoflavonoids (calycosin-7-O-β -glucoside, isomucronulatol 7-O-β-glucoside, formononetin) and two main saponins (astragaloside I, astragaloside IV) in an extract of Radix Astragali were determined using rapid, sensitive, reliable HPLC/UV and LC-ESI-MS/MS methods. The separation conditions employed for HPLC/UV were optimized using a phenyl-hexyl column (4.6 × 150 mm, 5 μm) with the gradient elution of acetonitrile and water as the mobile phase at a flow rate of 1.0 mL/min and a detection wavelength of 230 nm. The specificity of the peaks was determined using a triple quadrupole tandem mass spectrometer equipped with an electrospray ionization (ESI) source that was operated in multiple reaction monitoring (MRM) in the positive mode. These methods were fully validated with respect to the linearity, accuracy, precision, recovery and robustness. The HPLC/UV method was applied successfully to the quantification of three major isoflavonoids in the extract of Radix Astragali. The results indicate that the established HPLC/UV and LC-ESI-MS/MS methods are suitable for the quantitative analysis and quality control of multi-components in Radix Astragali.

LC-ESI-MS/MS를 이용한 평위산 주요 성분의 함량 분석 (Quantitative Determination of the Marker Components in Pyungwi-San Using LC-ESI-MS/MS)

  • 서창섭;신현규
    • 생약학회지
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    • 제49권3호
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    • pp.270-277
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    • 2018
  • Pyungwi-san has been used to treat the digestive system diseases, physconia, nausea, anorexia, and dyspepsia in Korea. In this study, an ultra-performance liquid chromatography-electrospray ionization-mass spectrometry (UPLC-ESI-MS/MS) method was optimized for simultaneous determination of the 14 marker components, spinosin, liquiritirn apioside, liquiritin, narirutin, 6'''-feruloylspinosin, hesperidin, liquiritigenin, glycyrrhizin, 6-gingerol, atractylenolide III, honokiol, atractylenolide II, magnolol, and atractylenolide I in Pyungwi-san extract. All analytes were separated on a Waters Acquity UPLC BEH $C_{18}$ analytical column ($2.1{\times}100mm$, $1.7{\mu}m$) with maintained at $45^{\circ}C$. The mobile phase consisted of 0.1% (v/v) aqueous formic acid and acetonitrile. The MS conditions were as follows: capillary voltage 3.3 kV, extractor voltage 3.0 V, RF lens voltage 0.3 V, source temperature $120^{\circ}C$, desolvation temperature $300^{\circ}C$, desolvation gas 600 L/h, cone gas 50 L/h and collision gas 0.14 mL/min. The coefficient of determination of 14 analytes was 0.9989-1.0000. The limits of detection and quantification values of the all analytes were 0.04-2.56 and 0.13-7.69 ng/mL, respectively. As a result of the analysis using the established LC-ESI-MS/MS method, the 5 components, spinosin, 6'''-feruloylspinosin, atractylenolide III, II, and I derived from Zizyphi Fructus and Atractylodis Rhizoma, were not detected in this extract. On the other hand, the 9 components except for the 5 components were 4.15-498.87 mg/kg in lyophilized Pyungwi-san extract. Among these components, glycyrrhizin, marker compound of Glycyrrhizae Radix et Rhizoma, was detected the most amount as a 498.87 mg/kg.