• 한국자기공명학회논문지
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• 제20권1호
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• pp.22-26
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• 2016

FANCJ is a DNA helicase which contributes genome stability by resolving G-quadruplex DNA from 5' to 3' direction. In addition to main ATPase helicase core, FANCJ has the protein binding region at its C-terminal part. BRCA1 and BLM are the binding partner of FANCJ and these protein-protein interactions contribute genomic stability and the proper response to replication stress. As the first attempt for studying FANCJ-BLM interaction, we prepared BLM binding region of FANCJ and characterized with CD and NMR spectroscopy. FANCJ (881-941) with N-ter 6xHis was purified as the oligomer. Secondary structure prediction based on CD data revealed that FANCJ (881-941) composed with ${\beta}$ sheet, turn and coils.$^1H-^{15}N$ HSQC spectra showed nonhomogeneous peak intensities with less number of peaks comparing than the number of amino acids in the construct. It indicated that optimization should be necessary for detailed further structural studies.

• Natural Product Sciences
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• 제10권5호
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• pp.220-222
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• 2004

A new prenylated pyranoxanthone, inophyllin B (1), was isolated from the roots of Calophyllum inophyllum (Guttiferae). Together with this compound was also isolated the known pyranoxanthone brasilixanthone B (2) and two common triterpenes friedelin (3) and sitosterol (4). Structural elucidations of these compounds were achieved through $^1H,\;^{13}C$, DEPT, COSY, HSQC and HMBC experiments. The molecular mass was determined using MS techniques. The crude extract indicated weak toxicity to the larvae of Aedes aegypti. We report here the isolation, structural elucidation and bioassay data for Inophyllin B and brasilixanthone B.

• 한국자기공명학회논문지
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• 제13권1호
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• pp.7-14
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• 2009

The spectral data were collected from the two 600 MHz spectrometers from the two major manufacturers, Broker and Varian. The samples were prepared to create standard curves for quantitative measurements of metabolite concentrations. Instead of employing one-dimensional $^1H$ experiments, the two-dimensional $^1H-^{13}C$ HSQC experiments were performed for better separation of resonances. For some resonances, the high salt condition hindered the linear correlation between the intensity and actual metabolite concentration. Excluding overlapped ones, most resonances showed good linearity. Although the Varian spectrometer showed better linearity, both spectrometers were able to generate acceptable standard curves. From this data, we could identify resonances that could be used to better quantify the concentrations of the particular metabolites. With these standard curves, the quantitative measurements of the metabolites from the real samples will be facilitated.

• 한국자기공명학회논문지
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• 제14권2호
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• pp.127-133
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• 2010

Redox-dependent conformational change of human 8-kDa Dynein light chain (LC8) plays important role in regulating NF-${\kappa}B$ signaling pathway. In this study we characterized the structural states of the oxidized and reduced forms of LC8 by using NMR spectroscopy. The $^1H-^{15}N$ 2D HSQC spectra of oxidized LC8 indicated that no significant change in tertiary structure of LC8 occurred upon oxidation. The chemical shift perturbations of LC8 upon oxidation suggest a redox-dependent quaternary structural change.

• Bulletin of the Korean Chemical Society
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• 제34권3호
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• pp.749-752
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• 2013

Trehalose-tethered monomeric and dimeric berberines were synthesized in 50% and 30% from the reaction of berberrubine with 6-tosyl-${\alpha}$,${\alpha}^{\prime}$-trehalose and 6,6'-ditosyl-${\alpha}$,${\alpha}^{\prime}$-trehalose, respectively, and fully characterized by MS (HR and ESI) and NMR ($^1H$, $^{13}C$, COSY and HSQC). Spectrophotometric and spectrofluorimetric titrations indicated that compared with berberine, trehalose-tethered monomeric berberine had comparable DNA-binding affinity toward calf-thymus DNA, whereas trehalose-spaced dimeric berberine exhibited higher DNA-binding affinity. The potential application of these conjugates is also briefly discussed.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.626-629
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• 2000

The Pseudomonas aeruginosa BYK-2(KCTC 18012p) produced three kinds of glycolipids on olive oil as a substrate and purified two types of major glycolipids(Rf=0.48, BS-1; Rf=0.65, BS-2) using silica gel chromatography, TLC, HPLC, etc. From the analysis of the chemical structure, the glycolipid of BS-1 was estimated as rhamnolipid($2-O-{\alpha}-L-rhamnopyranosyl- {\alpha}-L-rhamnopyranosyl-{\beta}-hydroxyldecanoyl-{\beta}-hydroxydecanoic$ acid; M.W. 650) and BS-2 was detected as rhamnolipid methyl ester($2-O-{\alpha}-L-rhamnopyranosyl-{\alpha}-L-rhamnopyranosyl-{\beta}-hydroxyldecanoyl-{\beta}-hydroxydecanoic$ acid methyl ester; M.W. 664) by FT-IR, FAB Mass spectrometry, $^1H-NMR$, $^{13}C$ FT-NMR, DEPT, 2D-NMR (TOCSY, RELAY, NOESY, HSQC, HMBC). In particular, It was found that a marine bacterium Pseudomonas aeruginosa BYK-2(KCTC 18012P) remarkably produced rhamnolipid and rhamnolipid methyl ester simultaneously.

• Natural Product Sciences
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• 제19권4호
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• pp.342-346
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• 2013

A new apotirucallane-type triterpenoid, $3{\alpha}$-tigloylsapelin D (1) together with five known triterpenoids such as meliasenin B (2), sendanolactone (3), (-)-$12{\beta}$-hydroxykulactone (4), cinamodiol (5), and $3{\alpha}$-hydroxytirucalla-7,24(25)-dien-6-oxo-21,16-olide (6) were isolated from the fruits of Melia azedarach. Their structures were established on the basis of various NMR spectroscopic analyses including 2D-NMR techniques (HSQC, HMBC, and NOESY) and HR-FAB-MS data.

• Natural Product Sciences
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• 제19권3호
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• pp.269-274
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• 2013

Nine terpenoids, spinasterone (1), simiarenol (2), phytol (3), lupeol (4), ${\alpha}$-amyrin (5), $1{\beta},4{\beta}$-dihydroxyeudesman-11-ene (6), 3,7-dihydroxyhumula-4,8(15),10(E)-triene (7), 2,6-dihydroxyhumula-3(12),7(13), 9E-triene (8), 23-hydroxybetulin (9) were isolated from the aerial parts of Aster yomena M. Their structures were identified based on 1D and 2D NMR, including $^1H-^1H$ COSY, HSQC, HMBC and NOESY spectroscopic analyses. Compounds 1 - 9 were isolated from this plant for the first time.

• Journal of the Korean Wood Science and Technology
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• 제43권5호
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• pp.558-565
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• 2015

Katsura tree (Cercidiphyllum japonicum Sieb. Et Zucc) leaves were collected, air-dried and extracted with 70% aqueous acetone, then concentrated and sequentially fractionated using n-hexane, methylene chloride ($CH_2Cl_2$), ethylacetate (EtOAc), and $H_2O$. The EtOAc fraction was chromatographed on a Sephadex LH-20 column with various aqueous MeOH eluting solvents and finally treated with acetone-$H_2O$ (7:3, v/v) to isolate a gallotannin. According to the NMR analysis, including HSQC and HMBC, and with the comparison of authentic literature data, the isolate was elucidated as 6-m-digalloyl-1,2,3,4-tetra-O-galloyl ${\beta}$-D-(+)-glucose, one of hydrolyzable tannins and one of gallotannins. The compound was only gallotannin which was firstly isolated from the extracts of Katsura tree leaves, and has not been reported before in domestic tree sources.

• Ocean and Polar Research
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• 제38권4호
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• pp.287-294
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• 2016

Marine sponges have been a remarkably rich source of pharmacologically active and structurally diverse natural products. As a part of our continuing search for novel secondary metabolites of biomedical importance from marine invertebrate, we encountered the sponge Lipastrotethya sp. from Chuuk, Micronesia. The crude organic extract of this animal exhibited considerable cytotoxicity against the K562 cell line. Guided by the $^1H$ NMR analysis, flash chromatography of the crude extract followed by HPLC yielded a new triterpene glycoside, along with ten known saponins of the sarasinoside class. The structure of this new compound was determined by combined spectroscopic methods such as COSY, HSQC and HMBC experiment. Among these metabolites, six compounds exhibited moderate cytotoxicity against ACHN, MDA-MB-231, NCI-H23 and NUGC-3 cell lines.