• Journal of the Korean Wood Science and Technology
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• v.32 no.1
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• pp.59-66
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• 2004

The dried neeldes(1.5 kg) of Juniperus rigida were ground, extracted with acetone-H₂O(7:3, v/v), concentrated, and fractionated with a series of hexane, CH₂Cl₂, EtOAc and water on a separatory funnel. Each fraction was freeze dried to give dark-brown powder and EtOAc and water soluble fractions were chromatographed on a Sephadex LH-20 column using a series of aqueous methanol and ethanol-hexane mixture as eluent. Spectrometric analysis such as NMR and FAB or EI-MS including TLC were performed to characterize the structures of the isolated compounds. The needles of Juniperus rigida contained a large amount of (+)-catechin, quercetin-3-O-α-L-rhamnopyranoside and isoconiferin, in addition to a small amount of umbelliferone and quercetin-3-O-β-D-rutinoside. The antioxidative activities of each fraction and isolated compounds were tested by DPPH radical scavenging method, and EtOAc soluble fraction, (+)-catechin and quercetin-3-O-α-L-rhamnopyranoside were effective.

• Journal of Microbiology and Biotechnology
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• v.23 no.2
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• pp.184-188
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• 2013

In the continued search for inhibitors of enoyl-acyl carrier protein (ACP) reductase, we found that four acylbenzenediol sulfate metabolites from Streptomyces sp. AN1761 potently inhibited bacterial enoyl-ACP reductases of Staphylococcus aureus, Streptococcus pneumoniae, and Mycobacterium tuberculosis. Their structures were identified as panosialins A, B, wA, and wB by MS and NMR data. They showed stronger inhibition against S. aureus FabI and S. pneumoniae FabK with $IC_{50}$ of 3-5 ${\mu}M$ than M. tuberculosis InhA with $IC_{50}$ of 9-12 ${\mu}M$. They also exhibited a stronger antibacterial spectrum on S. aureus and S. pneumoniae than M. tuberculosis. In addition, the higher inhibitory activity of panosialin wB than panosialin B on fatty acid biosynthesis was consistent with that on bacterial growth, suggesting that they could exert their antibacterial activity by inhibiting fatty acid synthesis.

• Bulletin of the Korean Chemical Society
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• v.23 no.12
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• pp.1778-1784
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• 2002

Novel membrane lipids containing the unusual very long chain fatty $acid{\alpha}{\omega}-1316-dimethyloctacosanedioate$, dimethyl. Ester (DME C30) was isolated and purified from thermophilic anaerobic eubacterium, Thermoanaerobacter ethanolicus. Structures of the lipids containing the bifunctional fatty acyl components were proposed by various analyses such as $^1H,\;^{13}C,\;^{31}P$ nuclear magnetic resonance (NMR), Fourier transform infrared(FTIR) spectroscopy, gas chromatography/mass spectrometry (GC/MS) and fast atom bombardment mass spectrometry (FAB/MS). Combined with the GC/MS, $^1H,\;and\;^{13}C$NMR data, we confirmed that the head groups of the lipids contained the glycerol and/or glucosamine molecules. $^{31}P$ NMR spectrum also showed that the lipids contained phosphate in a phosphodiester linkage. The proposed structures of these novel lipid components were the ones in which two head groups were linked by the membrane spanning fatty acyl component(DME C30)and regular chain fatty acids on glycerol moiety of each head group.

• Journal of the Korean Chemical Society
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• v.40 no.8
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• pp.557-564
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• 1996

FAB CAD MS/MS(Fast Atom Bombardment Collision Activated Dissociation Mass Spectrometry/Mass Spectrometry) was used to study different degree of bond stability according to the linkage positions of alkali cationized $(Na^+, Li^+, K^+, NH_4^+)$ stereoisomeric and synthetic oligosaccharides. The alkali metal cations were much more stable, requiring over -40 eV of collision energy vs. only -10 eV for the protonated forms. Of the cations, the potassium cationized trisaccharides were more stable than the others. They would not yield fragment ions under the conditions of collision available in triple quadrupole. Other cationized species exhibited decreasing stability in the series $Nap^+>Li^+>NH_4^+$ using 0.8 mTorr argon pressure in the collision cell. Metal cations of the oligosaccharides maintained charge principally on the amino sugar as shown by shift of all the fragment ions containing the amino sugar. The reason for the higher stability of the metal cationized form is the formation of crown ether-like bond around metal cations, N-acetyl group on GlcNAc and oxygens on fucose moiety. Depending on the metal sizes and the conformation of linkage-isomeric region, cationized species gave linkage dependent fragment patterns and exhibited stability in the series 1-6 > 1-4 > 1-3 linkage.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2006.11a
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• pp.285-289
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• 2006

In screening of algicidal bacteria, we isolated a marine bacterium which had potent algicidal effects on harmful algal bloom (HAB) species. This organism was identified as a strain very close to Bacillus subtilisby 16S rRNA gene sequencing. This bacterium, Bacillus sp. SY-1, produces very active algicidal compounds against the harmful dinoflagellate Cochlodinium polykrikoides. We isolated three algicidal compounds (MS 1056, 1070, 1084) and identified them by amino acid analyses, fast atom bombardment mass spectrometry (FAB-MS), infrared spectroscopy (IR), $^1H$, $^{13}C$, and extensive two-dimensional nuclear magnetic resonance (2D NMR) techniques including $^1H-^{15}N$ HMBC analysis. One of them, MS 1056, contains a b-amino acid residue with an alkyl side chain of $C_{15}$. MS 1056, 1070, and 1084 showed algicidal activities against C. polykrikoides with an $LC_{50}$ (6 hrs) of 2.3, 0.8, $0.6\;{\mu}g/ml$, respectively. These compounds also showed significant algicidal activities against other harmful dinoflagellates and raphidophytes. In contrast, MS 1084 showed no significant growth inhibition against various organisms coexisting with HAB species in natural environments, including bacteria, eukaryotic microalgae, and cyanobacteria, although it inhibited growth of some fungi and yeasts. These observations imply that algicidal bacterium Bacillus sp. SY-1 and its algicidal compounds could play an important role in regulating the onset and development of HABs in the natural environments.

• Food Science and Biotechnology
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• v.16 no.3
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• pp.349-354
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• 2007

The objectives of this study were to systemically identify phenolic compounds in roasted wild ginseng (Panax ginseng C.A. Meyer) leaves and investigate their radical scavenging activities. Seven phenolic compounds were identified by NMR (H, C, COSY, HMQC, HMBC) and mass (EI-MS, FAB-MS) analyses: 5-caffeoylquinic acid, kaempferol, quercetin, 3,4-dihydroxy-benzoic acid, 4-hydroxy-benzoic acid, 3-(3,4-dihydroxyphenyl)-2-propenoic acid, and 3-(4-hydroxy-3-methoxyphenyl)-2-propenoic acid. Their concentrations ranged from 0.4 (3,4-dihydroxy-benzoic acid) to 7.5 mg (kaempferol) per 100 g of roasted leaves. Among these compounds, 5-caffeoylquinic acid, kaempferol, and quercetin were found exclusively in the leaf portions of the ginseng plants. When their antioxidant activities were measured by DPPH and superoxide anion radical scavenging activity, quercetin, and kaempferol were most effective.

• Korean Journal of Pharmacognosy
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• v.27 no.2
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• pp.91-95
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• 1996

In the course of searching for acetylcholinesterase inhibitors from crude drugs, it was found that total MeOH extract of Corydalis Tuber showed significant inhibitory effect on acetylcholinesterase. To isolate acetylcholinesterase inhibitors from Corydalis Tuber, total MeOH extract of the the crude drug was subjected to activity guided fractionation. The MeOH extract was suspended in water and fractionated with methylene chloride and subjected to acid-base fractionation. Silica gel column chromatography of the basic fraction which showed significant inhibitory effect on acetylcholinesterase was carried out and 5 subfractions (1-5) were obtained. From subtraction 4, compound I was isolated. The structure of isolated compound I was identified by spectroscopic parameters of $^1H-NMR$, $^{13}C-NMR$, EI-MS and FAB-MS. The compound I was identified as berberine. It was found from the Lineweaver-Burk plot that berberine was a reversible and specific inhibitor of acetylcholinesterase having 90% inhibitory effect at the concentration of $2.5{\mu}M$.

• 한국태양에너지학회:학술대회논문집
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• 2012.03a
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• pp.397-399
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• 2012

Dye-sensitized solar cells (DSSCs) have received considerable attention as the most promising candidates for renewable energy systems in recent years. Among these, organic dyes which have many advantages such as large absorption coefficients, customized molecular design for desired photophysical and photochemical properties, inexpensiveness and environment-friendliness, are suitable as photosensitizers for DSSCs. We have studied on the design and synthesis of two organic dyes (BECZ 1 and BECZ 2) with a 9-ethyl-9H-carbazole core for dye-sensitized solar cells (DSSCs). Two organic dyes comprised of two 9-ethyl-9H-carbazole moiety as electron-donor, two types of cyanoacrylic acid moiety acting as acceptor. In addition, n-ethyl unit introduced for increasing the solubility and the donating power. The obtained organic dyes were comprehensively characterized by NMR, GC-MS, FAB-MS and UV/Vis spectroscopies. DSSCs sensitized by the dyes BECZ1 and BECZ2 produced ${\eta}$ value 3.31% and a ${\eta}$ value 3.21%.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1998.11a
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• pp.127-127
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• 1998

Specific inhibitors of a calcium activated neutral protease calpain could be used for the treatment of neurodegenerative diseases, cataract and muscular dystrophy diseases because of their therapeutic effects. In the course of screening for potential calpain inhibitors from microorganisms, a new analogue of chymostatins named calmostinol was isolated from the culture filtrate of an actinomycete. The MW was determined to be 596 [(M + H)$\^$+/] by FAB-MS in glycerol matrix. The structure was elucidated to be N-[((S)-1-carboxy-2-phenylethyl)-carbamoyl]-${\alpha}$-[2- iminohexahydro-4(S)-pyrimidyl]-L-glycyl- L-valyl-phenylalaninol, by the spectroscopic methods such as NMR and MS fragmentation studies. Calmostinol exhibited strong activity against calpain while not against a Ca$\^$2+/ -independent cysteine protease papain.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1998.11a
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• pp.134-134
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• 1998

The modulation of glycosidase activity by inhibitors is of great interest. Such compounds have been shown to be important tools in mechanistic studies on glycohydrolase as well as having promising therapeutic application. An ${\alpha}$-glucosidase inhibitor was isolated from culture filterates of Penicillium sp. The inhibitor was active against ${\alpha}$-glucosidase isolated from yeast and porcine small intestine. However, it showed no inhibition to Aspergillus ${\alpha}$-galactosidase, Escherichia coli ${\beta}$-galactosidase, and jack bean ${\alpha}$-mannosidase. The inhibitor was highly soluble in ether, methanol and chloroform. The inhibitor was purified using silica gel, Sephadex LH-20 column chromatography and reverse-phase HPLC. The inhibitory compound designated PA-7(IC$\sub$50/=35$\mu\textrm{g}$) was obtained as white powder. The structure of PA-7 was determined with spectroscopic data of EI-MS, FAB-MS, $^1$H, and $\^$13/C NMR. The inhibitor has a diketopiperazine moiety.