• Title/Summary/Keyword: 2D NMR techniques

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Brahol : A New Derivative of allo-Inositol from Stocksia brahuica

  • Ahmad, Viqar Uddin;Ali, Zulfiqar;Ali, Muhammad Shaiq;Zahid, Muhammad;Tareen, Rasool Bakhsh
    • Natural Product Sciences
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    • v.4 no.3
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    • pp.170-173
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    • 1998
  • A new derivative of allo-inositol has been isolated from the aerial parts of Stocksia brahuica and named as brahol (1). The structure of 1 was elucidated with the help of extensive 2D-NMR spectroscopic techniques and identified as 5-O-methyl-allo-inositol. The structure was reconfirmed by acetate derivative (2).

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Inhibitors of Adipogenesis in 3T3-L1 Cells Isolated from Wheat Bran (밀겨 유래의 3T3-L1 세포 지방생성 억제물질)

  • Jeong, Won-Sik;Hong, Seong-Su;Lee, Jung-A;Ahn, Eun-Kyung;Oh, Joa-Sub
    • Korean Journal of Pharmacognosy
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    • v.42 no.4
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    • pp.302-308
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    • 2011
  • As a part of our ongoing program on finding biologically active components from natural source we found three known constituents from the EtOH extract of the wheat bran. The known compounds were identified as tachioside (1), pinellic acid (2) and tryptophan (3). The structure and relative stereochemistry were determined from MS, 1D and extensive 2D NMR techniques as well as by comparison of their data with the published values. All isolates were tested their inhibitory effects on the adipogenesis in 3T3-L1 cells. The effect of compounds from wheat bran on 3T3-L1 adipocyte differentiation were measured by Oil Red O staining. These results demonstrate that tachioside (1) and pinellic acid (2) decreased lipid content in 3T3-L1 adipocytes by inhibiting lipogenesis. These compounds had shown antiobesity activities.

A Cytotoxic Monoterpene-Neolignan from the Stem Bark of Magnolia officinalis

  • Youn, Ui-Joung;Lee, Ik-Soo;Chen, Quan Cheng;Na, Min-Kyun;Jung, Hyun-Ju;Lee, Sang-Myung;Choi, Jae-Sue;Woo, Mi-Hee;Bae, Ki-Hwan;Min, Byung-Sun
    • Natural Product Sciences
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    • v.17 no.2
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    • pp.95-99
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    • 2011
  • A monoterpene-neolignan, piperitylmagnolol (1), was isolated from the stem bark of Magnolia officinalis, together with syringaresinol (2), caffeic acid (3), and sinapaldehyde (4). The isolated compounds were established on the basis of spectroscopic and physicochemical analyses including 1D- and 2D-NMR techniques, as well as on comparing the spectral data with those in the literature and of authentic samples. Compounds 1 - 4 were tested for their cytotoxic activity against the HeLa, K562, A549, and HCT116 cancer cell lines in vitro. Of the isolates, piperitylmagnolol (1) exhibited cytotoxic activity against the tested cancer cell lines with $IC_{50}$ values of 7.7 - 9.5 ${\mu}g/ml$.

Equimolar Carbon Dioxide Absorption by Ether Functionalized Imidazolium Ionic Liquids

  • Sharma, Pankaj;Park, Sang-Do;Park, Ki-Tae;Jeong, Soon-Kwan;Nam, Sung-Chan;Baek, Il-Hyun
    • Bulletin of the Korean Chemical Society
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    • v.33 no.7
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    • pp.2325-2332
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    • 2012
  • A series $[C_3Omim]$[X] of imidazolium cation-based ILs, with ether functional group on the alkyl side-chain have been synthesized and structure of the materials were confirmed by various techniques like $^1H$, $^{13}C$ NMR spectroscopy, MS-ESI, FTIR spectroscopy and EA. More specifically, the influence of changing the anion with same cation is carried out. The absorption capacity of $CO_2$ for ILs were evaluated at 30 and $50^{\circ}C$ at ambient pressure (0-1.6 bar). Ether functionalized ILs shows significantly high absorption capacity for $CO_2$. In general, the $CO_2$ absorption capacity of ILs increased with a rise in pressure and decreased when temperature was raised. The obtained results showed that absorption capacity reached about 0.9 mol $CO_2$ per mol of IL at $30^{\circ}C$. The most probable mechanism of interaction of $CO_2$ with ILs were investigated using FTIR spectroscopy, $^{13}C$ NMR spectroscopy and result shows that the absorption of $CO_2$ in ether functionalized ILs is a chemical process. The $CO_2$ absorption results and detailed study indicates the predominance of 1:1 mechanism, where the $CO_2$ reacts with one IL to form a carbamic acid. The $CO_2$ absorption capacity of ILs for different anions follows the trend: $BF_4$ < DCA < $PF_6$ < TfO < $Tf_2N$. Moreover, the as-synthesized ILs is selective, thermally stable, long life operational and can be recycled at a temperature of $70^{\circ}C$ or under vacuum and can be used repeatedly.

Synthetic Characteristics of AlPO$_4$-5 Molecular Sieve (AlPO$_4$-5 분자체의 합성 특성)

  • Sung Hwa Jhung;Suk Bong Hong;Young Sun Uh;Hakze Chon
    • Journal of the Korean Chemical Society
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    • v.37 no.10
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    • pp.867-873
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    • 1993
  • Influences of crystallization time and $H_2O/Al_2O_3$ ratio of the reaction mixtures on the synthesis of AlPO$_4$-5 molecular sieve have been studied by X-ray powder diffraction, nitrogen adsorption, scanning electron microscope (SEM), and solid state $^{27}$Al magic angle spinning nuclear magnetic resonance (MAS NMR) techniques. The degree of crystallinity of AlPO$_4$-5 follows a sigmoid pattem as crystallization time increases. The induction period is shorter than 1 h when the crystallization process is carried out at 150$^{\circ}$C. The conversion of reactants to product, AlPO$_4$-5, can be clearly observed, and all of the determined physical properties change abruptly after about 2 h. It is found that increase in $H_2O/Al_2O_3$ ratio of the reaction mixtures not only changes the crystal morphology from aggregates to hexagonal single crystals, but also results in the formation of longer AlPO$_4$-5 crystals.

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Interaction of flavins and some alcohols on the molecular level

  • Yu, Byung-Sul;Chung, Hyun-Ho;Lee, Sang-Jong;Kim, Yang-Bae;Kim, Chong-Kook
    • Archives of Pharmacal Research
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    • v.4 no.1
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    • pp.43-51
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    • 1981
  • The effect of some alcohols on the riboflavin derivatives in non-polar solvent was studied by various spectroscopic method in order to support the view point that alcohol may directly interect with the isoalloxazine moiety of FAD, the coenzyme of D-amino-acid oxidase. The most possible association complex between alcohol and riboflavin is the 1:1 complex through the 2-C carbonyl function of the isollaxazine ring nd the hydroxyl proton of alcohol. It is appeared that methanol has a larger association constant than any other alcohols, and the association constant decreases with the carbon number increases and being bulkier in the alkyl group of alcohols.

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Isolation and Identification of 13-Deacetyl-taxchinin I, a New Taxoid from Plant Cell Cultures of Taxus chinensis (식물세포 Taxus chinensis 배양으로부터 신물질 13-Deacetyl-taxchinin I의 분리 및 동정)

  • 김진현;기은숙;유시용;최형균;홍승서;이현수
    • KSBB Journal
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    • v.15 no.6
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    • pp.560-565
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    • 2000
  • 13-Deacetyl-taxchinin I, a taxoid having a rearranged 11(15\longrightarrow1)-abeo-taxane skeleton, has been isolated and identified from plant cell cultures of Taxus chinensis. The compound has not previously been encountered in nature. Its structure was elucidated by 1-and 2D NMR techniques including H-H COSY, HMQC, and HMBC experiments. This taxoid also provides information for better understanding of structure-activity relationships and biosynthesis, as well as improving the quality control of paclitaxel production.

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Two New Flavonoids from Dragon's Blood of Dracaena cambodiana

  • Mei, Wen-Li;Luo, Ying;Wang, Hui;Shen, Hai-Yan;Zeng, Yan-Bo;Dai, Hao-Fu
    • Bulletin of the Korean Chemical Society
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    • v.34 no.6
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    • pp.1791-1794
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    • 2013
  • Phytochemical investigation on dragon's blood of Dracaena cambodiana led to the discovery of two new flavonoid derivatives, cambodianin G (1) and cambodianin H (2). Their structures were elucidated on the basis of detailed spectroscopic analysis, including 1D and 2D NMR techniques and chemical methods. The two compounds were observed to exhibit antibacterial activities against Staphylococcus aureus, and compound 1 showed cytotoxicities against K562 and SGC-7901 cell lines.

Two New Phenolic Compounds from the Fruiting Bodies of Ganoderma tropicum

  • Hu, Li-Li;Ma, Qing-Yun;Huang, Sheng-Zhuo;Guo, Zhi-Kai;Guo, Jian-Chun;Dai, Hao-Fu;Zhao, You-Xing
    • Bulletin of the Korean Chemical Society
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    • v.34 no.3
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    • pp.884-886
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    • 2013
  • Chemical investigation of the fruiting bodies of Ganoderma tropicum led to the isolation of two new phenolic compounds, ganodermatropins A (1) and B (2). Their structures were elucidated by spectroscopic techniques (MS, 1D and 2D NMR). Ganodermatropin A exhibited antimicrobial activity against Staphylococcus aureus.

Purification and Structure Determination of Antifungal Phospholipids from a Marine Streptomyces

  • Cho, Ki-Woong;Seo, Young-Wan;Yoon, Tae-Mi;Shin, Jong-Heon
    • Journal of Microbiology and Biotechnology
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    • v.9 no.6
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    • pp.709-715
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    • 1999
  • A series of antifungal compounds were obtained from the methanol extract of the mycelium from marine actinomycetes M428 which was identified as a Stereptomyces species by fatty acid composition and biochemical characteristics. These compounds were purified by combined chromatographic techniques and the structures were characterized with spectroscopic methods including 1D and 2D NMR, and mass spectrometry as sn-l lysophosphatidyl inositols. The side chains were established by chemical degradation followed by GC analysis to be 14-methyl pentadecanoic acid (iso-palmitic acid, i-C16:0, compound A) and 13-methyl tetradecanoic acid (iso-pentadecanoic acid, i-C15:0, compound B). These compounds displayed highly selective antifungal activity against C. albicans with MIC values of $5{\;}\mu\textrm{g}/ml$ (compound A) and $2.5{\;}\mu\textrm{g}/ml$ (compound B), while it had almost negligible antibiotic activity against E. coli and P aerogenosa with MIC value higher than $50{\;}\mu\textrm{g}/ml$ and no cytotoxic activities against human myeloma leukemia K562 ($IC_{50}>100{\;}\mu\textrm{g}/ml$).

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