• Natural Product Sciences
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• v.22 no.1
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• pp.41-45
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• 2016

Extraction and fractionation of Pulsatilla koreana flowers followed by, repeated open column chromatography for EtOAc and n-BuOH fractions yielded four flavonoid glycosides, namely, astragalin (1), tiliroside (2), buddlenoide A (3), and apigenin-7-O-(3"-E-p-coumaroyl)-glucopyranoside (4). The chemical structures of these flavonoid glycosides were elucidated on the basis of various spectroscopic methods including electronic ionization mass spectrometry (EI-MS), 1D NMR ($^1H$, $^{13}C$, DEPT), 2D NMR (gCOSY, gHSQC, gHMBC), and infrared (IR) spectrometry. This study represents the first report of the isolation of the flavonoid glycosides from the flowers of P. koreana.

• Korean Journal of Food Science and Technology
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• v.33 no.3
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• pp.389-394
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• 2001

In order to isolate antimicrobial substances from Schizandra chinensis, the dried fruits were extracted with the methanol and the extract showed a strong antimicrobial activity. Also, the methanol exract was further fractionated with hexane, dichloromethane, ethylacetate and buthanol. The ethyl acetate-soluble fraction showed the strongest antimicrobial activity. These fraction were further separated by using various chromatographic methods including thin layer chromatography, silicagel open column chromatography and prep. HPLC. A major component S-EA-5-T1 and S-EA-5-T3 from the ethyl acetate fraction, which showed a strong antimicrobial activity was identified by Mass and NMR spectrometry. Two compounds were isolated and identified as trimethylcitrate and the essential oil of Schizandra chinensis and was estimated as gomisin C, respectively. The growth of S. typhimurium was also inhibited about 1.65 to 2.86 log cycle in minced pork by the addition 1% of Schizandra chinensis extract for 12 days at $4^{\circ}C$. These results suggested that these compounds have a strong potential as a natual food preservatives.

• Microbiology and Biotechnology Letters
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• v.33 no.2
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• pp.96-105
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• 2005

For screening of autoregulator receptor gene from Streptomyces longwoodensis, PCR was performed with primers of receptor gene designed on the basis of amino acid sequences of autoregulator receptor proteins with known function. PCR products were subcloned into the BamHIsite of pUC19 and transformed into the E. coli $DH5{\alpha}$. The isolated plasmid from transformant contained the fragment of 100 bp, which was detected on $2\%$ gel after BamHI treatment. The insert, 100 bp PCR product, was confirmed as the expected internal segment of gene encoding autoregulator receptor protein by sequencing. Southern and colony hybridizations with the 100 bp fragment as a probe allowed to select a genomic clone of S. longwoodensis, pSLT harboring a 4.4 kb SphI fragment. Nucleotide sequencing analyses revealed a 651 bp open reading frame(ORF) were isolated protein showing moderate homology ($35{\sim}46\%$) with the ${\Gamma}$-butyrolactone autoregulator receptors from Streptomyces sp., and this ORF was named sltR The sltR/pET-17b plasmid was constructed to overexpress the recombinant SltR protein (rSltR) in E. coli BL21 (DE3)/pLysS, and the rSltR protein was purified to homogeneity by DEAE-Sephacel column chromatography, and DEAE-5PW chromatography (HPLC). The molecular mass of the purified rSltR protein was 55 kDa by HPLC gel-filtration chromatography and 28 kDa by SDS-PAGE, indicating that the rSltR protein is present as a dimer. A binding assay with tritium-labeled autoregulators revealed that the rSltR has clear binding activity with a A-factor type autoregulator as the most effective ligand.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.8
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• pp.979-984
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• 2008

The stems of P etasites japonicus were extracted with ethanol and then partitioned with hexane, chloroform, ethyl acetate, n-butanol and water, successively. The antioxidant potency of five crude fractions were determined using (1) 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay, (2) thiobarbituric acid reactive substances (TBARS) assay in the linoleic acid model system, and (3) lipoxygenase inhibition assay. Among the crude fractions, the ethyl acetate fraction exhibited the most potent antioxidant effect. By activity-guided fractionation, compound PJ-4 was isolated from the ethyl acetate fraction through the repeated silica gel open column chromatography. The chemical structure of the isolated compound was determined as kaempferol by $^1H-$ and $^{13}C$-NMR analysis and its antioxidative capacity was further investigated. DPPH radical scavenging activity of the compound was 65.76% at the concentration of $100 \;{\mu}g/mL$. The inhibitory activity of the compound against lipid peroxidation and lipoxygenase exhibited 43.47% and 58.60%, respectively at the concentration of $100\;{\mu}g/mL$. The result suggests that the compound may serve as a useful natural antioxidant and furthermore indicates the possibility of developing the stems of Petasites japonicus as a natural antioxidant source.

• Korean Journal of Food Science and Technology
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• v.21 no.3
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• pp.391-398
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• 1989

Triglyceride molecular species In some vegetable oils were analyzed by capillary column gas chromatography and electron impact ionization mass spectrometry utilizing selected ion monitoring. Triglycerides were separated according to their molecular weights and their degrees of unsaturation on $25m{\times}0.25mm$ fused silica open tubular capillary column coated with a phenylmethylsilicone gum stationary phase and in an analysis time less than 13 min. Triglyceride molecular species were identified by analyzing the fragment ions having the same time on the selected ion monitoring profile . The major triglyceride molecular species in each oils were $C_{18:1}.\;C_{18:2}.\;C_{18:2}(OLL:18.3%),\;C_{18:2}.\;C_{18:2}.\;C_{18:2}(LLL;\;14.3%),\;C_{18:0}.\;C_{18:2}.\;C_{18:2}(SLL;\;14.1%),\;C_{16:0}.\;C_{18:2}.\;C_{18:2}(PLL;\;13.2%),\;C_{16:0}.\;C_{18:2}.\;C_{18:1}(PLO;\;11.6%)$ in corn oil, $C_{18:2}.\;C_{18:2}.\;C_{18:2}(LLL;\;18.0%),\;C_{18:1}.\;C_{18:2}.\;C_{18:2}(OLL;\;18.0%),\;C_{16:0}.\;C_{18:2}.\;C_{18:2}(PLL;\;17.1%)$ in safflower oil, $C_{16:0}.\;C_{18:2}.\;C_{18:2}(PLL;\;23.5%),\;C_{16:0}.\;C_{18:2}.\;C_{18:1}(PLO;\;13.8%),\;C_{18:0}.\;C_{18:1}.\;C_{18:1}(SOO;\;13.5%),\;C_{18:1}.\;C_{18:2}.\;C_{18:2}(OLL;\;10.6%)$ in cottonseed oil.

• Korean Journal of Food Science and Technology
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• v.45 no.2
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• pp.174-179
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• 2013

Three low-molecular compounds were isolated from methanol extracts of pear (Pyrus pyrifolia N. cv. Chuhwangbae) fruit peels using solvent fractionation, various types of column chromatogrphy (Diaion HP-20, Sephadex LH-20, and silica gel), and high performance liquid chromatography with an assay guided by 1,1-diphenyl-2-picrylhydrazyl radical-scavenging activity. The isolated compounds were identified as 2-carboxyl-4(1H)-quinolinone (kynurenic acid, 1) from butanol fraction, cis-p-coumaric acid (2) from ethyl acetate-acidic fraction, and vanillin (3) from the ethyl acetate-phenolic fraction, respectively. These isolated compounds were confirmed on the basis of the spectroscopic data of electrospray ionization mass spectrometry and nuclear magnetic resonance. This is the first time that compounds 1-3 were isolated and identified in pear.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.3
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• pp.179-183
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• 1998

The cyanidin 3-glucoside (C3G) extracted from pigmented rice seeds in 0.5% TFA (Trifluoro acetic acid) -95% ethanol was separated by High Performance Liquid Chromatography (HPLC). A HPLC system using a Develosil ODS-5 column and 0.1 % TFA-$H_2O$～0.1 % TFA-$CH_3CN$ gradient elution was selected for separation and quantitative determination of C3G. Regression equation obtained for the standard content of C3G pigment was as Y=21.95293$^*$X-14.726771 (r=0.99$^{**}$). Using this method, 326 domestic and introduced collections were evaluated for the C3G content. The Korean bred cultivar 'Heugjinjubyeo', showed highest C3G content (552 mg/100g seed) among the tested cultivars. Among the pigmented rice cultivars ten cultivars were selected for containing a high content of C3G. The content of C3G per 100g seeds was in high order as follows: Heugjinjubyeo (552mg)>Cheng Chang (321mg)>Kilimgeugmi (240mg)>PI160979-2 (224mg)>Hong Shei Lo (221mg)>Heugnambyeo (191 mg)>Mitak =PIl60979-1 (186mg)>Suwon425 (163mg)>Sanghaehyanghyeolla (108mg). The C3G pigment was not detected in the common white rice cultivars.

• Journal of Microbiology and Biotechnology
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• v.16 no.1
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• pp.77-83
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• 2006

A gene encoding a $\gamma-butyrolactone$ autoregulator receptor was cloned from Saccharopolyspora erythraea, and the biochemical characteristics, including the autoregulator specificity, were determined with the purified recombinant protein. Using primers designed for the conserved amino acid sequence of Streptomyces $\gamma-butyrolactone$ autoregulator receptors, a 120 bp S. erythraea DNA fragment was obtained by PCR. Southern and colony hybridization with the 120 bp fragment as a probe allowed to select a genomic clone of S. erythraea, pESG, harboring a 3.2 kb SacI fragment. Nucleotide sequencing analysis revealed a 615 bp open reading frame (ORF), showing moderate homology (identity, $31-34\%$; similarity, $45-47\%$) with the $\gamma-butyrolactone$ autoregulator receptors from Streptomyces sp., and this ORF was named seaR (Saccharopolyspora erythraea autoregulator receptor). The seaR/pET-3d plasmid was constructed to overexpress the recombinant SeaR protein (rSeaR) in Escherichia coli, and the rSeaR protein was purified to homogeneity by DEAE-Sephacel column chromatography, followed by DEAE-ion-exchange HPLC. The molecular mass of the purified rSeaR protein was 52 kDa by HPLC gel-filtration chromatography and 27 kDa by SDS-polyacrylamide gel electrophoresis, indicating that the rSeaR protein is present as a dimer. A binding assay with tritium-labeled autoregulators revealed that rSeaR has clear binding activity with a VB-C-type autoregulator as the most effective ligand, demonstrating for the first time that the erythromycin producer S. erythraea possesses a gene for the $\gamma-butyrolactone$autoregulator receptor.

• Natural Product Sciences
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• v.17 no.4
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• pp.367-371
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• 2011

Effects of the extract and fractions from Parasenecio pseudotaimingasa on rat lens aldose reductase (AR) inhibition have been investigated. Among them, the n-BuOH fraction was exhibited good inhibitory potencies ($IC_{50}$ value 1.42 ${\mu}g/ml$). Phytochemical constituents were isolated from the n-BuOH fraction by open column chromatography. Their structures were elucidated as luteolin-7-O-rutinoside (1) and luteolin-7-Oglucoside (2) on the basis of spectroscopic analysis. Compounds 1 and 2 exhibited strong AR inhibitory activity, with $IC_{50}$ values of 2.37 and 1.05 ${\mu}M$, respectively. This is the first report on the isolation of compounds 1 and 2 from P. pseudotaimingasa. These results suggest that P. pseudotaimingasa could be a useful material in the development of a novel AR inhibitory agent against diabetic complications.

• Journal of Microbiology and Biotechnology
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• v.13 no.1
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• pp.139-145
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• 2003

The gene encoding Thermus caldophilus GK24 polyphosphate kinase (Tca PPK) was cloned and sequenced. The gene contains an open reading frame encoding 608 amino acids with a calculated molecular mass of 69,850 Da. The deduced amino acid sequence of Tca PPK showed a 40% homology to Escherichia coli PPK, and $39\%$ to Klebsiella aerogenes PPK. The Tca ppk gene was expressed under the control of the T7lac promoter on pET-22b(+) in E. coli and its enzyme was purified about 70-fold with $36\%$ yield, following heating and HiTrap chelating HP column chromatography. The native enzyme was found to have an approximate molecular mass of 580,000 Da and consisted of eight subunits. The optimum pH and temperature of the enzyme were 5.5 and $70^{\circ}C$, respectively. A divalent cation was required for the enzyme activity, with $Mg^2+$ being the most effective.