• Natural Product Sciences
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• v.17 no.3
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• pp.183-188
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• 2011

A bisdesmosidic cholestane glycoside was isolated from the rhizomes of Polygonatum sibiricum and the structure was elucidated by spectroscopic methods and acid hydrolysis as (22S)-cholest-5-ene-$1{\beta}$,$3{\beta}$,$16{\beta}$,22-tetrol 1-O-${\alpha}$-L-rhamnopyranosyl 16-O-${\beta}$-D-glucopyranoside. This compound exhibited weak cytotoxic activity with the $IC_{50}$ value, $63.6\;{\mu}M$ in human MCF-7 breast cancer line, whereas it failed to show agonistic activity at $100{\mu}M$ in TGR5 assay with Chinese hamster ovary (CHO) cells. This is the first report of a bisdesmosidic cholestane glycoside from Polygonatum species and the full assignments of $^1H$, $^{13}C$ NMR by HMBC, TOCSY and NOESY experiments were provided.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2006.04a
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• pp.77-90
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• 2006

Beta-amyloid peptide (A$\beta$) is a major component of senile plaques and its aggregation is considered to play a critical role in pathogenesis of Alzheimer's disease (AD). Aggregation of A$\beta$ could result from both increased synthesis and decreased degradation of A$\beta$. Our laboratory is interested in understanding the mechanism of A$\beta$ degradation in brain. Recently our laboratory identified a bacterial gene (SKAP) from Streptomyces sp KK565 whose protein product has an activity to cleave A$\beta$ and thus reduce the A$\beta$-induced neurotoxicity. The sequence analysis showed that this gene was closely related to aminopeptidase. Maldi-Tof analysis showed that the recombinant SKAP protein expressed in E. coli cleaves both A$\beta$ 40 and A$\beta$ 42 at the N-terminal of A$\beta$ while an aminopeptidase from Streptomyces griseus (SGAP) cleaves at the C-terminal. We also identified a mammalian homolog of SKAP and the recombinant mammalian protein expressed in Sf-9 insect cells showed a similar proteolytic activity to SGAP, cutting A$\beta$ at the C-terminus. I well discuss the detailed mechanism of the enzyme action and its functional implication in AD.

• Natural Product Sciences
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• v.4 no.1
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• pp.45-50
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• 1998

Seven triterpenoid saponins such as oleanolic acid 28-O-{\beta}-D-glucopyranosyl$ ester, hederagenin $28-O-{\beta}-D-glucopyranosyl$ ester, chikusetsusaponin IVa, udosaponin A, salsoloside C, udosaponins F and C were isolated from the aerial parts of Aralia continentalis, among which two $28-O-{\beta}-D-glucopyranosyl$ esters of oleanolic acid and hederagenin are isolated for the first tome from this plant. These results suggested that the chemical components of Korean Dokwhal are practically identical to those of japanese Udo supporting the chemotaxonomical point of view.

• Natural Product Sciences
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• v.6 no.2
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• pp.96-101
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• 2000

The ethanolic extract of the heartwood of Taxus baccata L. afforded six taxoids, belonging to the skeletally three different groups, $2{\alpha},\;5{\alpha},\;10{\beta}-triacetoxy-14{\beta}-(2-methyl)-butryloxy-4(20)$,11-taxadiene (1), taxusin (2), baccatin VI (3), baccatin III (4), $1{\beta}-hydroxybaccatin$ I (5) and taxol (6). The isolation and structure elucidation of three taxoids (3-5) have been presented in this study. This is the first report for the presence of these taxoids in Taxus baccata L. growing in Turkey.

• Natural Product Sciences
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• v.10 no.5
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• pp.237-239
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• 2004

Mallotus nepalensis (Euphorbiaceae) is a small tree found in central and eastern Himalayas, Nepal, Wallich and Sikkim. The 90% ethanolic extract of Mallotus nepalensis exhibited mild CNS depressant activity. Four compounds, lupeol (1), ${\beta}-sitosterol$ (2), ursolic acid (3) and ${\beta}-sitosterol-\;{\beta}-D-glucoside$ (4) were isolated from the 90% ethanolic extract of this plant of which 1, 3 and 4 are being reported for the first time from this species.

• Natural Product Sciences
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• v.12 no.2
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• pp.101-103
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• 2006

In the course of the continual work on the fresh tubers of Gastrodia elata, a fructoside constituent was isolated from the n-butanol soluble fraction prepared from the methanol extract. The structure of this compound was identified as $n-butyl-{\beta}-D-fructopyranoside$ from various spectroscopic data including $^1H-\;and\;^{13}C-NMR$, HMQC, HMBC, and FABMS.

• Culinary science and hospitality research
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• v.22 no.3
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• pp.224-239
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• 2016

The purpose of this study is to understand the influence of customer-based brand equity(CBBE) on brand trust, customer satisfaction, and repurchase intention in the stock farm products brand, Hoengsung hanwoo. Based on a total of 301 samples obtained from empirical research, this study reviewed the reliability and fitness of the research model and verified a total of 5 hypotheses using the AMOS program. The hypothesized relationships in the model were tested simultaneously by using a structural equation model(SEM). The proposed model provided an adequate fit of the data, ${\chi}^2=635.175$(p<0.001), df=233, CMIN/DF=2.726, GFI=0.863, NFI=0.859, CFI=0.903, TLI=0.885, RMSEA=0.068. The model's fit, as indicated by these indexes, was deemed satisfactory, thus providing a good basis for testing the hypothesized paths. The SEM showed that the sublevels of CBBE of stock farm product brand such as perceived product quality(${\beta}=.562$) and brand image(${\beta}=.377$) had a positive significant influence on brand trust. In addition, brand trust had a positive significant influence on customer satisfaction(${\beta}=.525$) and repurchase intention(${\beta}=.669$). This study confirms that a firm brand management works as a significant factor in forming brand trust, and, as a result, has a positive impact on its consumer's satisfaction and repurchase intention. Through the studys' results, it is study proposed that there is a needs for establishing effective marketing strategies to improve of regional economies.

• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.3
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• pp.215-218
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• 2000

Sialytrisaccharides based on $\beta$-galactosyldisaccharides were synthesized using $\beta$-galactosidase and trans-sialidase in one pot. Using $\beta$-galactosidase from Bacillus Ciculans and trans-sialidase from Trypanosoma cruzi simulaneously, 6mM sialyltrisaccharides composed of about 95% NeuAc$\alpha$(2,3)Gal$\beta$(1,4)GlcNAc and 5% NeuAc$\alpha$(2,3)Gal$\beta$(1,6)GlcNAc were produced from a reaction mixture containing 25mM o-nitropheny1-$\beta$-D-galsctolneuraminic acid. One beauty of this reaction was that a secondary hydrolysis of the disaccharide intermediate occurring between the activated galactopyranoside and N-acetylgucosamine was prevented. Using $\beta$-galactosidase from Escherichia cloi and the same trans-sialidase, 15mM sialyltrisaccharides composed of about 90% NeuAc$\alpha$(2,3)Gal$\beta$(1,6)GlcNac and 10% NeuAc$\alpha$(2,3)Gal$\beta$(1,4)GlcNAc were produced from a reaction misture containing 400nM galactose, 800nM N-acetylglucosylation rection between galactose and N-actylgucosamine was diminant since the disaccharide intermediate mainly resulted sreulted in the silylated product.

• Microbiology and Biotechnology Letters
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• v.25 no.2
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• pp.137-143
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• 1997

Porcine transforming growth factor-$\beta$1 (TGF-$\beta$1) was expressed in Escherichia coli using cDNA of TGF-$\beta$1 and glutathione S-transferase (GST) fusion vector pGEX-1$\lambda$T. An ApoI-Tth111I fragment of cDNA which correspond to the amino acid residues from 123 to 390 of the precursor TGF-$\beta$1 was inserted into EcoRI-Tth111I digested pGEM#-l$\lambda$T and the recombined plasmid was named pGET-12. Gene products from the cloned regions of the recombinant plasmids pGET-12 was not detected in soluble fraction of cell free extract but detected in insoluble fraction. The solubilization of insoluble gene product was achieved by the treatment of N-laurylsarcosine. Molecular weight of partially purified proteins determined by electrophoresis was same as expected from cloned fragment. The ELISA test results of the purified proteins showed that immunologically detectable epitope was preserved in recombinant protein.

• Natural Product Sciences
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• v.6 no.3
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• pp.135-138
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• 2000

MeOH extract of Cuscuta chinensis seeds was fractionated with n-hexane, EtOAc and BuOH successively, and antioxidant activities were tested for all fractions using DPPH free radical scavenging method. In the tested fractions, EtOAc fraction showed high antioxidant activity$(EC_{50},\;50\;{\mu}g)$ From the EtOAc fraction, five compounds have been isolated. On the basis of spectral data, these compounds were identified as ${\beta}-sitosterol$, methyl 4-hydroxy-3,5-dimethoxycinnamate, ${\beta}-sitosterol-3-O-{\beta}-D-glucopyranoside$, caffeic acid, quercetin, kaempferol and calycopteretin. Among these compounds, ${\beta}-sitosterol$ and ${\beta}-sitosterol-3-O-{\beta}-D-glucopyranoside$ showed no antioxidant activity. $EC_{50}$ values of methyl 4-hydroxy-3,5-dimethoxycinnamate, caffeic acid, quercetin, kaempferol and calycopteretin were 0.6, 8, 19, 17 and $12\;{\mu}g$, respectively.