• Title/Summary/Keyword: ESI MS

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Two New Caffeoyl Threonate Esters from the Leaves of Toxicodendron vernicifluum

  • Jang, Jae Young;Ahn, Jong Hoon;Jo, Yang Hee;Turk, Ayman;Kang, So Young;Hwang, Bang Yeon;Lee, Mi Kyeong
    • Natural Product Sciences
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    • v.25 no.4
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    • pp.354-357
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    • 2019
  • Toxicodendron vernicifluum, also called as Rhus verniciflua is a deciduous tree belonging to Anacardiaceae family. Two new caffeoyl threonate esters, rhuseols A (1) and B (2), together with 5-O-(E)-caffeoylquinic acid methyl ester (3) were isolated from the leaves of T. vernicifluum. The structures of isolated compounds were established by using 1D and 2D NMR in combination with HR-ESI-MS. Compounds 1 - 3 showed DPPH radical scavenging effects with IC50 values of 47.9, 107.8 and 15.4 μM, respectively. Taken together, these compounds might contribute to the antioxidant properties of the leaves of T. vernicifluum, which will be useful for various oxidative stress mediated diseases.

Chemical Constituents of Nelumbo nucifera Seeds

  • Rho, Taewoong;Yoon, Kee Dong
    • Natural Product Sciences
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    • v.23 no.4
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    • pp.253-257
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    • 2017
  • The phytochemical study for the extract of Nelumbo nucifera (Nymphaceae) seeds has led to the isolation of ten compounds including five simple phenolic compounds, two indole derivatives, a flavonoid glycoside, two abscisic acid derivatives. The interpretation of 1D and 2D NMR and ESI-Q-TOF-MS spectroscopic data revealed the chemical structures of isolates to be p-hydroxybenzoic acid (1), protocatechuic acid (2), (E)-p-coumaric acid (3), (E)-ferulic acid (4), (E)-sinapate-4-O-${\beta}$-$\text\tiny{D}$-glucopyranoside (5), tryptophan (6), 3-indoleacetic acid (7), isoschaftoside (8), dihydrophaseic acid (9), dihydrophaseic acid 3'-O-${\beta}$-$\text\tiny{D}$-glucopyranoside (10). To the best of our knowledge, 1 - 5 and 7 were identified for the first time from N. nucifera seeds, and the presence of dihydrophaseic acid (9) and its glucoside (10) were demonstrated secondly in this plant.

Isolation of Prenylated Isoflavonoids from Cudrania tricuspidata Fruits that Inhibit A2E Photooxidation

  • Uddin, Golam Mezbah;Lee, Hee-Ju;Jeon, Je-Seung;Chung, Dong-Hwa;Kim, Chul-Young
    • Natural Product Sciences
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    • v.17 no.3
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    • pp.206-211
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    • 2011
  • High-performance liquid chromatography coupled to an online $ABTS^+$-based assay (online HPLC-$ABTS^+$) system was used to determine the principal antioxidants in Cudrania tricuspidata fruits. Six prenylated isoflavonoids (1 - 6) were isolated from C. tricuspidata fruits according to the online HPLC-$ABTS^+$ system. The structures of isolated compounds, alpiniumisoflavone (1), 6,8-diprenylorobol (2), 6,8-diprenylgenistein (3), pomiferin (4), 4'-methylalpiniumisoflavone (5), and osajin (6) were identified by their retention time, UV spectra, ESI-MS, and NMR data. Among these compounds, 6,8-diprenylorobol (2) and pomiferin (4) reduced A2E photooxidation in a dose dependent manner.

Antibacterial Compound against Pasteurella haemolytica is produced from Streptomyces sp. 51086

  • Kang, Hee-Chol;In- Ja Ryoo;Yun, Bong-Sik;Yu, Seung-Hun;Yoo, Ick-Dong
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1998.11a
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    • pp.129-129
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    • 1998
  • The Pasteurella haemolytica-induced pneumonic lesions are frequently occurred with stress and infection of virus in the cattle. In the course of screening for antimicrobial activity against Pasteurella haemolytica, compound 51086 has been isolated from the fermentation broth of the strain streptomyces sp. The compound 51086 was purified by column chromatography and HPLC, subsequently. The structure of compound 51086 was determined as a hygromycin A by a combination of $^1$H NMR, $\^$l3/C NMR, HMBC, and ESI -MS. This compound showed significant antibacterial activity against P. haemolytica and P. multocidn in Gram-negative bacteria.

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Purification and Characterization of a New κ-Carrageenase from the Marine Bacterium Vibrio sp. NJ-2

  • Zhu, Benwei;Ning, Limin
    • Journal of Microbiology and Biotechnology
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    • v.26 no.2
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    • pp.255-262
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    • 2016
  • The carrageenan-degrading marine bacterium Vibrio sp. strain NJ-2 was isolated from rotten red algae, and κ-carrageenase with high activity was purified from the culture supernatant. The purified enzyme with molecular mass of 33 kDa showed the maximal activity of 937 U/mg at 40℃ and pH 8.0. It maintained 80% of total activity below 40℃ and between pH 6.0 and 10.0. The kinetics experiment showed the Km and Vmax values were 2.54 g/ml and 138.89 mmol/min/mg, respectively. The thin layer chromatography and ESI-MS analysis of hydrolysates indicated that the enzyme can endolytically depolymerize the κ-carrageenan into oligosaccharides with degrees of depolymerization of 2-8. Owing to its high activity, it could be a valuable tool to produce κ-carrageenan oligosaccharides with various biological activities.

2-Aminothiazolinium Based Tripodal Receptors:Synthesis and Recognition of Oxoanions

  • Nguyen, Quynh Pham Bao;Le, Thanh Nguyen;Kim, Taek-Hyeon
    • Bulletin of the Korean Chemical Society
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    • v.30 no.8
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    • pp.1743-1748
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    • 2009
  • Novel 2-aminothiazolinium based tripodal receptors were designed and synthesized. The binding property of these receptors toward various anions was investigated by the isothermal titration calorimetry (ITC) method. Receptor 4 recognized the acetate anion with 1:1 stoichiometry, whereas it bound the other oxoanions such as sulfate and phosphate in complex modes. By modifying the phenyl groups at the 4-position of the thiazoline rings of the tripodal receptor 4 to induce a mutual aromatic stacking interaction among the three ligands, receptor 10 showed totally different binding behavior, which gave rise to the 1:1 binding mode for the sulfate anion. This result was confirmed by ESI MS spectrometry.

Characterization of Extremely Hydrophobic Immunostimulatory Lipoidal Peptides by Matrix Assisted Laser Desorption Ionization Mass Spectrometry

  • 장정석;이성택;장윤석
    • Bulletin of the Korean Chemical Society
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    • v.17 no.11
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    • pp.1036-1039
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    • 1996
  • Synthetic lipoidal peptides based on viral protein sequences have been prepared. These peptides contain an N-palmitoyl group at the N-terminal residue, which is a modified cysteine, containing a S-[2,3-bis(acyloxy)-(2-R,S)-propyl] moiety. When this residue (Pam3Cys) is at the N-terminus of a synthetic peptide, it acts as potent immunoadjuvant to enhance both IgM and IgG antibody responses to the attached peptide. Conventional analytical procedures (e.g., Edman degradation and amino acid analysis) are either not applicable due to the N-terminal modification, or do not provide confirmation of the intact structure. Chromatographic analysis is also hindered by the tendency of these lipoidal Pam3Cys peptides to form large aggregates, and in some cases to be permanently adsorbed on reversed phase columns. We have applied several mass spectrometric techniques, including fast atom bombardment (FAB), electrospray ionization (ESI) and matrix assisted laser desorption ionization (MALDI) to characterize the intact structures of a number of different Pam3Cys synthetic peptides. The MALDI-MS has been found to be the most sensitive for the analysis of the structure of Pam3Cys peptides.

A New Cycloartane Glycoside from Camptosorus sibiricus Rupr.

  • Ning-Li;Xian-Li;Peng-Zhang;Li, Zhan-Lin;Yang, Shi-Lin;Wang, Jin-Hui
    • Archives of Pharmacal Research
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    • v.27 no.7
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    • pp.727-729
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    • 2004
  • A new cycloartane glycoside was isolated from the dried whole herbs of Camptosorus sibiricus Rupr By means of chemical (hydrolysis) and spectroscopic methods (IR, 1D, and 2D NMR, ESI-MS), the structure was established as $3{\beta}$, $7{\beta}$, $24{\beta}$, 25, 30-pentahydroxycycloartane-3-O-${\beta}$-D-glucopyranoside-24-O-${\beta}$-D-glucopyranoside (1).

Chemical Constituents from Aegle marmelos Fruits

  • Kim, Hye Jin;Seo, Young Ju;Htwe, Khin Myo;Yoon, Kee Dong
    • Natural Product Sciences
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    • v.27 no.4
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    • pp.240-244
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    • 2021
  • Aegle marmelos (Rutaceae) is a deciduous shrub or tree and typically known as bael throughout Southeast Asia and has been used as a medicinal plant and a food ingredient. In this study eight compounds were determined to be O-(3,3-dimethylallyl) halfordinol (1), (R)-aegeline (2), (R)-marmeline (3), imperatorin (4), xanthotoxol (5), valencic acid (6), vanillic acid (7) and rutin (8). The chemical structures of the isolates were elucidated through spectroscopic evidence including 1D, 2D NMR, ESI-Q-TOF-MS and optical rotation.