• Title/Summary/Keyword: High-resolution mass spectrometry

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Chemotaxonomic Significance of Catechin 7-O-beta-D-apiofuranoside in Ulmus Species

  • KIM, Mi;LEE, Yong Jo;SHIN, Jae-Cheon;CHOI, Sun Eun
    • Journal of the Korean Wood Science and Technology
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    • v.48 no.6
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    • pp.888-895
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    • 2020
  • Ulmus genus has excellent various physiological activities, including anti-ulcer, antioxidant, antibacterial, anti-cancer, immunity, and homeostasis maintenance effects, and it is known to have many additional drug effects And one of reasons for these excellentbiological activities is a flavan-3-ol chemical group in Ulmus genus. In this study a new flavan-3-ol compound was identified in Ulmus davidiana var. japonica. A flavan-3-ol,(2R,3S)-7-[(2S,3R,4R)-3,4-dihydroxy-4-(hydroxymethyl)oxolan-2-yl]oxy-2-(3,4-dihydroxyphenyl)-3,4-dihydro-2H-chromene-3,5-diol, named as catechin 7-O-beta-D apiofuranoside, was isolated from the stems and barks of Ulmus davidiana var. japonica for. suberosa, which is a species belonging to the genus Ulmus, growing throughout the Korea peninsula. The structure was elucidated by various spectroscopic methods including high-resolution TOF mass spectrometry, 1H-NMR and 13C-NMR spectrometry and comparison with chemical structures of defined compounds.

Bioconversion of Tetracycline Antibiotics to Novel Glucoside Derivatives by Single-Vessel Multienzymatic Glycosylation

  • Pandey, Ramesh Prasad;Chu, Luan Luong;Kim, Tae-Su;Sohng, Jae Kyung
    • Journal of Microbiology and Biotechnology
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    • v.28 no.2
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    • pp.298-304
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    • 2018
  • The single-vessel multienzyme UDP-${\alpha}$-$\text\tiny{D}$-glucose recycling system was coupled with a forward glucosylation reaction to produce novel glucose moiety-conjugated derivatives of different tetracycline antibiotic analogs. Among five tetracycline analogs used for the reaction, four molecules (chlorotetracycline, doxytetracycline, meclotetracycline, and minotetracycline) were accepted by a glycosyltransferase enzyme, YjiC, from Bacillus licheniformis to produce glucoside derivatives. However, the enzyme was unable to conjugate sugar units to rolitetracycline. All glucosides of tetracycline derivatives were characterized by ultraviolet absorbance maxima, ultra-pressure liquid chromatography coupled with photodiode array, and high-resolution quadruple time-of-flight electrospray mass spectrometry analyses. These synthesized glucosides are novel tetracycline derivatives.

Terpenoids from Citrus unshiu Peels and Their Effects on NO Production

  • Vu, Thi Oanh;Seo, Wonyoung;Lee, Jeong Hyung;Min, Byung Sun;Kim, Jeong Ah
    • Natural Product Sciences
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    • v.26 no.2
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    • pp.176-181
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    • 2020
  • Two new compounds, 3-methyl-but-2-en-1-yl-1-O-β-xylopyranosyl-(1"→2')-O-β-glucopyranoside (1) and 1-O-β-glucopyranosyl-6-hydroxy-2-methyl-hep-2-enoic acid (2), along with sixteen known terpenoids were isolated from the peels of Citrus unshiu Markov. Their structures were elucidated based on extensive NMR analyses (1H NMR, 13C NMR, DEPT, COSY, HMQC, and HMBC) and high-resolution mass spectrometry. In addition, all isolates (1 - 18) were tested their effects on nitric oxide (NO) production in RAW264.7 cells. Limonin (15) showed to inhibit LPS-induced NO production in a concentration-dependent manner without cytotoxicity.

Small-molecule probes elucidate global enzyme activity in a proteomic context

  • Lee, Jun-Seok;Yoo, Young-Hwa;Yoon, Chang No
    • BMB Reports
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    • v.47 no.3
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    • pp.149-157
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    • 2014
  • The recent dramatic improvements in high-resolution mass spectrometry (MS) have revolutionized the speed and scope of proteomic studies. Conventional MS-based proteomics methodologies allow global protein profiling based on expression levels. Although these techniques are promising, there are numerous biological activities yet to be unveiled, such as the dynamic regulation of enzyme activity. Chemical proteomics is an emerging field that extends these types proteomic profiling. In particular, activity-based protein profiling (ABPP) utilizes small-molecule probes to monitor enzyme activity directly in living intact subjects. In this mini-review, we summarize the unique roles of smallmolecule probes in proteomics studies and highlight some recent examples in which this principle has been applied.

Intramolecualr cyclization of a dipyrromethane by an electrophilic aromatic substitution reaction producing a new chiral compound

  • Kim, Seung Hyun;Kim, Sung Kuk
    • Journal of the Korean Magnetic Resonance Society
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    • v.22 no.4
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    • pp.115-118
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    • 2018
  • Dipyrromethane 2 functionalized with 3-chloropropyl group on the meso carbon undergoes an unusual intramolecular electrophilic aromatic substitution reaction in the presence of $NaN_3$ instead of a simple nucleophilic substitution reaction. As a result, a new chiral dipyrromethane 1 was synthesized. In this reaction, the ${\beta}$-carbon of the pyrrole ring functions as a nucleophile while the carbon next to the chlorine atom acts as an electrophile. Interestingly, this reaction progresses even in the absence of an acid catalyst. Compound 1 was fully characterized by $^1H-^1H$ and $^1H-^{13}C$ COSY NMR spectroscopic analyses and the high resolution EI mass spectrometry.

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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    • v.26 no.4
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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.

Quantitation of L-carnitine in plasma by electrospray ionization tandem mass spectrometry (ESI/MS/MS를 이용한 혈장 중 카르니틴 정량분석)

  • Kang, Seung Woo;Kim, Ho Hyun;Lee, Kyung Ryul;Yoon, Hye-Ran
    • Analytical Science and Technology
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    • v.18 no.2
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    • pp.163-167
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    • 2005
  • In this study, a novel analytical method has been developed for the rapid determination of L-carnitine in human plasma using electrospray ionization tandem mass spectrometry. Free carnitine (FC) was analyzed after extraction with 80% methanol and total carnitine (TC) was analyzed after hydrolysis and extraction. Acyl carnitine (AC) was subtracted FC from TC. Analytical methods used multiple reaction monitoring (MRM) scan modes. A correlation coefficient of linear regression ($r^2$) was 0.9995, recovery was 97%, reproducibility was less than 10%, and limit of detection (LOD) was $0.0016{\mu}mol/L$. This method reduced sample preparation time and showed high resolution and good reproducibility compared to that with liquid chromatographic methods. Normal control showed AC was lower than FC. Clinical management of patients with inborn error of metabolism showed FC was lower than AC. Thus, carnitine fraction level was very important to monitoring patients with metabolic disorder.

Proteomic Analysis of Resting and Activated Human $CD8^+$ T Cells

  • Koo Jung-Hui;Chae Wook-Jun;Choi Je-Min;Nam Hyung-Wook;Morio Tomohiro;Kim Yu-Sam;Jang Yang-Soo;Choi Kwan-Yong;Yang Jung-Jin;Lee Sang-Kyou
    • Journal of Microbiology and Biotechnology
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    • v.16 no.6
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    • pp.911-920
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    • 2006
  • [ $CD8^+$ ] T Iymphocytes with the cytotoxic activity and capability to release various cytokines are the major players in immune responses against viral infection and cancer. To identify the proteins specific to resting or activated human CD8$^+$ T cells, human CD8$^+$ T cells were activated with anti-CD3+anti-CD28 mAb in the presence of IL-2. The solubilized proteins from resting and activated human CD8$^+$ T cells were separated by high-resolution two-dimensional polyacrylamide gel electrophoresis, and their proteomes were analyzed. Proteomic analysis of resting and activated T cells resulted in identification of 35 proteins with the altered expression. Mass spectrometry coupled with Profound and SWISS-PROT database analysis revealed that these identified proteins are to be functionally associated with cell proliferation, metabolic pathways, antigen presentation, and intracellular signal transduction pathways. We also identified six unknown proteins predicted from genomic DNA sequences specific to resting or activated CD8$^+$ T cells. Protein network studies and functional characterization of these novel proteins may provide new insight into the signaling transduction pathway of CD8$^+$ T cell activation.

Comparing eight types of ginsenosides in ginseng of different plant ages and regions using RRLC-Q-TOF MS/MS

  • Dai, Yu-Lin;Qiao, Meng-Dan;Yu, Peng;Zheng, Fei;Yue, Hao;Liu, Shu-Ying
    • Journal of Ginseng Research
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    • v.44 no.2
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    • pp.205-214
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    • 2020
  • Background: This article aims to compare and analyze the contents of ginsenosides in ginseng of different plant ages from different localities in China. Methods: In this study, 77 fresh ginseng samples aged 2-4 years were collected from 13 different cultivation regions in China. The content of eight ginsenosides (Rg3, Rc, Rg1, Rf, Rb2, Rb1, Re, and Rd) was determined using rapid resolution liquid chromatography coupled with quadrupole-time-of-flight tandem mass spectrometry (RRLC-Q-TOF MS/MS) to comparatively evaluate the influences of cultivation region and age. Results: Ginsenoside contents differed significantly depending on age and cultivation region. The contents of ginsenosides Re, Rc, Rg1, Rg3, and Rf increased with cultivation age, whereas that of ginsenoside Rb1 peaked in the third year of cultivation. Moreover, the highest ginsenoside content was obtained from Changbai (19.36 mg/g) whereas the lowest content was obtained from Jidong (12.05 mg/g). Ginseng from Jilin Province contained greater total ginsenosides and was richer in ginsenoside Re than ginseng of the same age group in Heilongjiang and Liaoning provinces, where Rb1 and Rg1 contents were relatively high. Conclusion: In this study, RRLC-Q-TOF MS/MS was used to analyze ginsenoside contents in 77 ginseng samples aged 2-4 years from different cultivation regions. These patterns of variation in ginsenoside content, which depend on harvesting location and age, could be useful for interested parties to choose ginseng products according to their needs.

A Proteomic Approach for Quantitative Analysis of Calcitonin Gene-related Peptides in the Cerebrospinal Fluid Obtained from a Rat Model of Chronic Neuropathic Pain (만성 신경병성 통증이 유발된 쥐의 뇌척수액에서 단백체학을 이용한 Calcitonin Gene-related Peptides의 정량분석)

  • Kim, Dong Hee;Hong, Sung Ho
    • The Korean Journal of Pain
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    • v.21 no.2
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    • pp.112-118
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    • 2008
  • Background: This study was conducted to quantitatively analyze proteins associated with the calcitonin gene-related peptide (CGRP) in cerebrospinal fluid (CSF) that was obtained from a rat model of chronic neuropathic pain following administration of intrathecal $CGRP_{8-37}$. Methods: Male Sprague-Dawley rats (100-150 g, 5-6 wks) were divided into two groups, sham controls and neuropathic pain models. At the time of operation for neuropathic pain model, an intrathecal catheter was threaded through the intrathecal space. At 1 or 2 wks after the operation (maximum pain state), a test dose of 1, 5, 10, or 50 nM of $CGRP_{8-37}$ was injected into the intrathecal catheter and the CSF was then aspirated. Conventional proteomics to evaluate the CSF were then performed using high resolution 2-D, gel electrophoresis followed by computational image analysis and protein identification by mass spectrometry. Results: Treatment with $CGRP_{8-37}$ effectively alleviated mechanical allodynia in a dose dependent manner. The most effective response was obtained when a dose of 50 nM was administered, but significant differences were obtained following administration of only 5 nM $CGRP_{8-37}$. Furthermore, the results of the proteomic analysis were consistent with the experimental results. Specially we detected 30 differentially expressed spots in 7 images when 2-D gel electrophoresis was conducted. The intensity of 6 of these spots (spot number: 20 and 26-30) was found decrease the $CGRP_{8-37}$ dose increased; therefore, these spots were evaluated by mass spectrometry. This analysis identified 2 different proteins, CGRP (spot numbers: 26-30) and neurotensin-related peptide (spot number: 20). Conclusions: The results of this study suggest that CGRP plays a role in chronic central neuropathic pain and is a major target of chronic neuropathic pain management.