• Journal of Microbiology and Biotechnology
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• v.14 no.4
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• pp.751-758
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• 2004

The NCS(Non-Cariogenicity Sugar) from Bacillus sp. S-1013 was purified by cold acetone and methanol precipitation, and DEAE-cellulose ion-exchange and Sephadex G-100 column chromatographies, to yield an amorphous yellow syrup. The melting point and $[\alpha]_D^{20}$ were 155-$157^{\circ}C$ and +53, respectively. Instrumental analyses such as FT-IR, $^1H-NMR, and ^{13}C-NMR$ showed that the NCS contained an O-H group, C-H, C=O, $NH_2$, anomeric carbon, anomeric proton, N-acetylgalactose, fucose, and neuramic acid, thus, the NCS was determined to be a trisaccharide of Fuc($1\longrightarrow4$)GalNAc($2\longrightarrow6$) NeuAc.

• Korean Journal of Pharmacognosy
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• v.49 no.2
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• pp.108-112
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• 2018

Four quinolone alkaloids, 2-heptyl-4-quinolone (1), 2-nonyl-4-quinolone (2), 2-undecyl-4-quinolone (3), and 2-undecen-1'-yl-4-quinolone (4), together with two nitrogen derived benzoic acid derivatives, N-acetylanthranilic acid (5) and o-acetamidobenzamide (6) have been isolated from the Arctic bacterial strain, Pseudomonas aeruginosa. The structures of the compounds were determined by 1D and 2D NMR, and MS experiments, as well as by comparison of their data with published values. To the best of our knowledge, compounds 3-6 were isolated for the first time from P. aeruginosa.

• Polymer(Korea)
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• v.34 no.2
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• pp.159-165
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• 2010

Dipyridine-terminated polystyrenes and polybutadienes were synthesized by the chain endfunctionalization reaction of polystyryllithium (PSLi) and polybutadienyllithium (PBDLi) with di(2-pyridyl) ketone(DPK) using a living anionic polymerization method in the Ar-glove box. Living polymeric lithiums with low molecular weights (Mw=1000~2000 g/mol) were used to investigate the chain end-functionalization yield with DPK and the degree of coupling reaction by the attack of organolithium to the pyridine ring in the presence of TMEDA using GPC, $^1H$-NMR, $^{13}C$ analysis. DPK-terminated PBD exhibited much higher functionalization yield and less amount of coupling reaction compared with DPK-terminated PS. 86% functionalization yield with 9% degree of coupling was obtained when the PBDLi was added dropwise to DPK solution at room temperature. The functionalization yield was increased as the reaction temperature decreased, however, no LiCl effect was observed in this chain end-functionalization reaction with DPK.

• Applied Biological Chemistry
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• v.41 no.2
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• pp.197-200
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• 1998

The MeOH extracts obtained from the flower petals of Carthamus tinctorius were solvent-fractionated with EtOAc, n-BuOH, and $H_2O$, successively. From the n-BuOH extract 2 flavonoid compounds were isolated through the repeated silica gel column chromatographies. From not only the results of physico-chemical data including HMBC but also the adaptation of acid hydrolysis, the chemical structures of the compounds were determined as $3-O-[{\beta}-D-glucopyranosyl(1{\rightarrow}2)\;{\beta}-D-glucopyranosyl]\;kaempferol$ and $3-O-[{\alpha}-L-rhamnopyranosyl(1{\rightarrow}6)\;{\beta}-D-glucopyranosyl]\;kaempferol$. The compounds exhibited $IC_{50}$ values in Grab2-Shc activity to be 43 and $47{\mu}g/ml$, respectively.

• Journal of Applied Biological Chemistry
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• v.59 no.1
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• pp.19-23
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• 2016

A phenol substance was extracted from Pinus koraiensis Siebold et Zucc leaf extracts and its biological efficacy was measured. The highest content of the phenol substance contained in Pinus koraiensis Siebold et Zucc leaves was 13.5 mg/g, which was obtained when it was extracted with 80% ethanol. At a concentration of 200 mg/mL, the phenolic substances extracted with 80% ethanol and water showed antimicrobial activities against Helicobacter pylori, producing clear zones of 10 and 12 mm diameter, respectively. Pinus koraiensis Siebold et Zucc. leaf extracts were separated using a Sephadex LH-20 column and 4 fractions were obtained (fractions A-D). Fractions C and D showed the greatest inhibitory activity against Helicobacter pylori producing 10.1 and 12.3 mm clear zones, respectively. These two fractions were purified using a Sephadex LH-20 and MCI-gel column ($H_2O{\rightarrow}100%$ ethanol). Purified compounds A and B were identified as syringic acid and compound C was identified as p-coumaric acid based on $^1H$-nuclear magnetic resonance (NMR), $^{13}C$-NMR, and fast atom bombardment mass spectrometry spectra. When two or more purified compounds were mixed, a synergistic effect of anti-Helicobacter pylori activity was evident. This result indicates that extracts of Pinus koraiensis Siebold et Zucc leaves could be considered a functional food because of their high antimicrobial properties.

• 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.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.477-480
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• 2002

A thermostable xylanase from Thermotoga maritima (Xyn B) cleaves several pNP-glycosides of monosaccharides. We found that the initial product of the cleavage of pNP-xyloside (pNP-Xy1) was a disaccharide, not xylose, indicating that xylosyl unit of pNP-Xyl was transglycosylated to another pNP-Xyl. We determined that the disaccharide was xylobiose which has the linkage of the ${\beta}$ 1-4, and described the reaction mechanism of the Xyn B. Also, we produced the several pNP-glycosides and propyl-disaccharides from the transglycosylation of Xyn B with varial glycosides and/or 1-propanol. All reaction products were purified by column chromatography (Toyo-pearl HW-40C, 45 cm${\times}$2.5 cm or 45 cm ${\times}$ 2.5 cm${\times}$ 2). The isolated products were analyzed by means of 1D and 2D NMR.

• Journal of Microbiology and Biotechnology
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• v.15 no.2
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• pp.384-387
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• 2005

Four new antibiotic peptaibols, named neoatroviridins A (1), B (2), C (3), and D (4), have been isolated from the culture broth of Trichoderma atroviride. Their amino acid sequences were determined mainly by mass spectrometry in combination with NMR studies. The absolute stereochemistry of neoatroviridins was established as L by GC analysis of their acid hydrolysates with derivatization, except for isovaline which was in D. Neoatroviridins, composed of 18 amino acid residues, showed significant membrane-perturbing activity responsible for their antibiotic action, which was comparable to that of alamethicin, a well-known 20-residue peptaibol.

• Natural Product Sciences
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• v.21 no.4
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• pp.289-292
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• 2015

Intensive chemical investigation of Korean marine sponge Spongia sp. has led to the isolation of two new scalaranes. The planar structures of the new compounds 1 and 2 were determined through 1D and 2D NMR spectral data analysis, while the relative stereochemistry of the compounds was determined based on the analysis of $^1H-^1H$ coupling constants and NOESY spectroscopic data. Compounds 1 and 2 did not display any significant biological activities on farnesoid X-activated receptor (FXR) in co-transfection assay.

• Natural Product Sciences
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• v.15 no.2
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• pp.106-109
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• 2009

Phytochemical investigations of the EtOAc-soluble fraction of the whole plants of Salvia plebeia using repeated column chromatography with preparative HPLC led to the isolation of a new phenylbutanone glucoside, 4-{4-0-[6-(4-hydroxybenzoyl)-0-${\beta}$-D-glucopyranosyl]-3-hydroxyphenyl}-butan-2-one (salviaplebeiaside, 1) along with two known phenolic compounds, rosmarinic acid methyl ester (2) and luteolin-7-0-${\beta}$-D-glucoside (3). The structures of these compounds were determined on the basis of spectroscopic methods including 1D-, 2D-NMR and MS spectrometry and comparison of spectroscopic data with those of values reported in the literatures.